WO2025006415A2

WO2025006415A2 - Surface-modified textiles

Info

Publication number: WO2025006415A2
Application number: PCT/US2024/035332
Authority: WO
Inventors: Jeffrey M. Catchmark; Kang Zhang
Original assignee: Penn State Research Foundation
Current assignee: Penn State Research Foundation
Priority date: 2023-06-28
Filing date: 2024-06-25
Publication date: 2025-01-02
Anticipated expiration: 2025-12-28
Also published as: WO2025006415A3

Abstract

This document relates to textiles. For example, textiles (e.g., water-repellent textiles) as well as methods for modifying textiles to alter one or more properties of the textiles are provided. In some cases, a textile can be modified to be more water-repellent and/or more oil-repellent. For example, a textile containing one or more cellulose fibers can be modified to have one or more charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile containing one or more synthetic fibers can be produced to have one or more charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent).

Description

SURFACE-MODIFIED TEXTILES

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Patent Application Serial No. 63/523,800, filed on June 28, 2023. The disclosure of the prior application is considered part of, and is incorporated by reference in, the disclosure of this application.

STATEMENT REGARDING FEDERAL FUNDING

This invention was made with government support under Hatch Act Project No. PEN04602 awarded by the United States Department of Agriculture. The Government has certain rights in the invention.

TECHNICAL FIELD

This document relates to textiles. For example, this document provides textiles (e.g., water-repellent textiles) as well as methods for modifying textiles to alter one or more properties of the textiles. In some cases, a textile can be modified to be more water-repellent. For example, a textile (e.g., a textile containing one or more cellulose fibers) can be modified to have one or more hydrophilic charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant, containing a hydrophilic cationic moiety and a hydrophobic moiety) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile (e.g., a textile containing one or more synthetic fibers) can be produced to have one or more hydrophilic charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant containing a hydrophilic cationic moiety and a hydrophobic moiety) to render the surface of the textile more hydrophobic (e.g., more water-repellent). In addition, this document relates to textiles having a surface coating of one or more hydrophilic charged (e.g., negatively charged) moieties, and having a surfactant (e.g., a cationic surfactant containing a hydrophilic cationic moiety and a hydrophobic moiety) bonded (e.g., electrostatically bonded, ionically bonded, or covalently bonded) to the charged moieties. In some cases, a textile having a surface coating of one or more hydrophilic charged (e.g., negatively charged) moieties, and having surfactant (e.g., a cationic surfactant containing a hydrophilic cationic moiety and a hydrophobic moiety) bonded (e.g., electrostatically bonded, ionically bonded, or covalently bonded) to the charged moieties can have the ability to repel water. These textiles can be simultaneously oil resistant. Oil resistance can be achieved by positioning the hydrophilic charged moieties on the surface beneath the hydrophobic moiety of the surfactant. These textiles can be simultaneously oil-repellent and water resistant or simultaneously water- repellent and oil resistant. This can be achieved by placing hydrophilic charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a molecule with an oppositely charged moiety on both ends of the molecule (e.g., positively charged) where the molecule has a hydrophobic central region.

BACKGROUND INFORMATION

Waterproof and water-repellent materials are frequently used in a wide range of applications including clothing fabrics, and various items of socks, hosiery, footwear, upholstery (e.g., fabrics for outdoor furniture), carpets, and window treatments, as well as for industrial textile end uses. Chemical coatings have long been used to create waterproof and water-repellent fabrics. However, research has shown that the chemicals typically used in these coatings can harm the environment or even harm humans, accumulating in both to their detriment.

SUMMARY

This document provides modified textiles and methods for making modified textiles (e g., water-repellent textiles). For example, this document provides modified textiles (e.g., water-repellent textiles) as well as methods for modifying textiles to alter one or more properties of the textiles. In some cases, a textile can be modified to be more water-repellent. For example, a textile (e.g., a textile containing one or more cellulose fibers) can be modified to have one or more hydrophilic charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant containing a hydrophilic cationic moiety and a hydrophobic moiety) to render the surface of the textile more hydrophobic (e.g., more water-repellent). In some cases, a textile containing one or more cellulose fibers can be modified such that at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) are converted to charged (e.g., negatively charged) moieties (e.g., anionic acid groups), and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile (e.g., a textile containing one or more synthetic fibers) can be produced to have one or more hydrophilic charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant containing a hydrophilic cationic moiety and a hydrophobic moiety) to render the surface of the textile more hydrophobic (e.g., more water-repellent). In some cases, a textile containing one or more synthetic fibers can be produced in the presence of a first surfactant (e.g., an anionic surfactant such as a fatty acid) (e.g., and thereby incorporating the first surfactant), such that charged (e.g., negatively charged) regions of the first surfactant are present on the surface of the textile, and the textile can subsequently be contacted with a second surfactant (e.g., a cationic surfactant such as lauric arginate) to render the surface of the textile more hydrophobic (e.g., more water- repellent). In some cases, a textile containing one or more synthetic fibers can be produced incorporating the first surfactant, such that charged (e.g., negatively charged) regions of the first surfactant are present on the surface of the textile.

This document also provides textiles having a surface coating of one or more charged (e.g., negatively charged) moieties, and having a surfactant (e.g., a cationic surfactant) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the charged moieties. For example, a textile (e.g., a textile containing one or more cellulose fibers) can include one or more negatively charged moieties on its surface, and can have a cationic surfactant attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the negatively charged moieties. For example, a textile (e.g., a textile having one or more synthetic fibers) can have (e.g., can be engineered to have) one or more charged (e.g., negatively charged) moieties on its surface, and can have a surfactant (e.g., a cationic surfactant) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the charged moieties. In some cases, a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the negatively charged moieties can have the ability to repel water. For any charge herein, the opposite charge can be employed. For instance and without limitation, a textile can be modified or produced to have one or more hydrophilic charged (e.g., positively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., an anionic surfactant containing a hydrophilic anionic moiety and a hydrophobic moiety) to render the surface of the textile more hydrophobic (e.g., more water-repellent). In some cases, a textile containing one or more synthetic fibers can be produced in the presence of a first surfactant (e.g., a cationic surfactant such as a fatty amine or lauric arginate) (e.g., and thereby incorporating the first surfactant), such that charged (e.g., positively charged) regions of the first surfactant are present on the surface of the textile, and the textile can subsequently be contacted with a second surfactant (e.g., an anionic surfactant such as a fatty acid) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile can have a surface coating of one or more charged (e.g., positively charged) moieties, and having a surfactant (e.g., an anionic surfactant) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the charged (e.g., positively charged) moieties.

In addition to surfactants, other molecules can be attached to charged (e.g., negatively charged and positively charged) regions disposed on a surface of a textile. For example, a molecule can include a non-toxic molecule containing a hydrophobic central region and a positively charged cationic region at both ends, wherein at least one end is attached to negatively charged regions present on a surface of a textile. For example, a molecule can include a non-toxic molecule containing a hydrophobic central region and a negatively charged cationic region at both ends, wherein at least one end is attached to positively charged regions present on a surface of a textile.

A textile containing a cationic surfactant (containing a hydrophilic cationic moiety and a hydrophobic moiety) or other molecule (e.g., containing a hydrophobic central region and a positively charged cationic region at both ends) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to a hydrophilic negatively charged moieties on its surface can also be simultaneously oil resistant. A textile containing an anionic surfactant (containing a hydrophilic anionic moiety and a hydrophobic moiety) or other molecule (e.g., containing a hydrophobic central region and a negatively charged anionic region at both ends) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to a hydrophilic positively charged moieties on its surface can also be simultaneously oil resistant. Oil resistance can be achieved by positioning the hydrophilic charged moieties on the surface of the textile beneath the hydrophobic moiety of the surfactant.

As demonstrated herein, textiles can be modified to be more water-repellent using non-toxic surfactants or other non-toxic molecules. In some cases, textiles that contain cellulose fibers can be rendered hydrophobic by modifying the surface of the textile to contain one or more negatively charged moieties, and then contacting the functionalized textile with a cationic surfactant under conditions where the cationic surfactant forms a bond (e.g., an electrostatic bond, an ionic bond, or a covalent bond) with the negatively charged moieties to render the surface of the textile hydrophobic. In some cases, synthetic textiles can be rendered hydrophobic by synthesizing the textile in the presence of an anionic surfactant (e.g., and thereby incorporating the anionic surfactant), such that the surface of the synthetic textile contains one or more negatively charged moieties, and then contacting the synthetic textile with a cationic surfactant or other cationic molecule under conditions where the cationic surfactant forms a bond or attachment (e.g., an electrostatic bond, an ionic bond, or a covalent bond) with the negatively charged moieties to render the surface of the textile hydrophobic. In some cases, synthetic textiles can be rendered hydrophobic by synthesizing the textile in the presence of a cationic surfactant (e.g., and thereby incorporating the cationic surfactant), such that the surface of the synthetic textile contains one or more positively charged moieties, and then contacting the synthetic textile with an anionic surfactant or other anionic molecule under conditions where the anionic surfactant forms a bond or attachment (e g., an electrostatic bond, an ionic bond, or a covalent bond) with the positively charged moieties to render the surface of the textile hydrophobic. Even though the textile’s surface is hydrophobic and thus water-repellant, it can also resist the penetration of oil since a hydrophilic moiety is present underneath the hydrophobic moiety. This hydrophilic moiety will resist the penetration of the oil.

Having the ability to impart both hydrophobicity and oil resistance to textile materials as described herein (e.g., by modifying a textile to have one or more negatively charged moieties on its surface, and subsequently contacting the textile with a cationic surfactant) provides an ecologically compatible processes to render a textile to be water-repellent and oil resistant. For example, the methods provided herein can be used to render a textile water- repellent and oil resistant while leaving no environmentally toxic compounds on the material that may reside in soils or waterways through wear, washing, or disposal.

Having the ability to impart both hydrophilicity and oil repellency to textile materials as described herein (e.g., by modifying a textile to have one or more negatively charged moieties on its surface, and subsequently contacting the textile with a molecule that has a hydrophilic cationic moiety on either end of a molecule that has a hydrophobic central region) also provides an ecologically compatible processes to render a textile to be oilrepellent and water resistant. For example, the methods provided herein can be used to render a textile oil-repellent and water resistant while leaving no environmentally toxic compounds on the material that may reside in soils or waterways through wear, washing, or disposal.

Repellency and resistance can exist on a spectrum. For example and without limitation, repellency can be characterized by a high contact angle, and resistance may lack such a high contact angle, but the fluid (e.g., oil or water) will not penetrate into the textile.

Accordingly, in one aspect, a textile comprise cellulose fibers, wherein said cellulose fibers comprise a surface modification comprising surface hydroxyl groups converted to anionic acid groups and further comprising a cationic surfactant attached to said anionic acid groups to modify the surface. In some implementations, said textile is more water-repellent than a comparable textile lacking said surface modification.

In another aspect, a method includes modifying a textile comprising cellulose fibers to increase its hydrophobicity.

In another aspect, a textile comprises synthetic fibers, an anionic surfactant, and a coating attached to at least some of said synthetic fibers, wherein said synthetic fibers contains said anionic surfactant such that negatively charged regions of said anionic surfactant are present on a surface of said textile. In some implementations, said textile is more water-repellent than a comparable textile lacking said coating.

In some implementations, said coating comprises a non-toxic cationic surfactant attached to said negatively charged regions. In some implementations, said coating comprises a non-toxic molecule containing a hydrophobic central region and a positively charged cationic region at both ends, wherein at least one end is attached to said negatively charged regions. In another aspect, a textile comprises synthetic fibers, a cationic surfactant, and a coating attached to at least some of said synthetic fibers, wherein said synthetic fibers contains said cationic surfactant such that positively charged regions of said cationic surfactant are present on a surface of said textile.

In some implementations, said coating comprises a non-toxic anionic surfactant attached to said positively charged regions. In some implementations, said coating comprises a non-toxic molecule containing a hydrophobic central region and a negatively charged anionic region at both ends, wherein at least one end is attached to said positively charged regions.

In another aspect, a textile comprises synthetic fibers and a charged surfactant, wherein said synthetic fibers contains said charged surfactant such that charged regions of said charged surfactant are present on a surface of said textile and such that hydrophobic regions of said charged surfactant have diffused into the surface of said textile.

In some implementations, said charged surfactant comprises an anionic surfactant, and said charged regions comprise negatively charged regions. In some implementations, said charged surfactant comprises a cationic surfactant, and said charged regions comprise positively charged regions

In another aspect, a method includes modifying a textile comprising synthetic fibers to increase its hydrophobicity.

In another aspect, a method includes modifying a textile comprising synthetic fibers to provide one or more charged moieties.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF THE DRAWINGS

Figures 1 A - IB. Water penetration of 100% cotton woven fabric that was dyed black before (Figure 1A) and after (Figure IB) cotton functionalization and hydrophobic functionalization with lauric arginate.

Figures 2A - 2B. Water penetration of 50% cotton - 50% recycled polyester woven fabric before (Figure 2 A) and after (Figure 2B) cotton functionalization and hydrophobic functionalization with lauric arginate.

Figures 3A - 3B. Images of water penetration of untreated nylon fabric. A water droplet added to a nylon fabric (Figure 3A) started to diffuse after 34 minutes and completely disappeared after 45 minutes (Figure 3B).

Figures 4A - 4B. Images of water penetration of nylon fabric treated with an anionic surfactant. A water droplet added to a nylon fabric treated with octanoic acid (Figure 4A) started to diffuse after 48 seconds (Figure 4B).

Figures 5A - 5B. Images of water penetration of nylon fabric treated with a cationic surfactant. A water droplet added to a nylon fabric treated with octadecylamine (Figure 5A) began to reduce the contact angle and started to diffuse after 38 minutes (Figure 5B).

Figures 6A - 6C. Images of water penetration of nylon fabric treated with an anionic surfactant and a cationic surfactant. A water droplet added to a nylon fabric treated with octanoic acid and octadecylamine (Figure 6A) did not diffuse into the fabric after 45 minutes (Figure 6B). After 270 minutes, the water did not diffuse and maintained a contact angle of over 90 degrees (Figure 6C).

Figures 7A - 7B. Images of water penetration of untreated polypropylene fabric. A water droplet added to a polypropylene fabric (Figure 7A) maintained a high contact angle at 45 minutes and for over 4 hours, but the contact angle started to reduce and the water started to diffuse after 270 minutes (Figure 7B).

Figures 8A - 8B. Images of water penetration of polypropylene fabric treated with an anionic surfactant. A water droplet did not form on the surface of a polypropylene fabric treated with octanoic acid (Figure 8A) and diffused completely within in minutes. After 45 minutes, no trace of the water could be observed (Figure 8B).

Figures 9A - 9B. Images of water penetration of polypropylene fabric treated with a cationic surfactant. A water droplet added to a polypropylene fabric treated with octadecylamine formed a high contact angle (Figure 9A) but started to diffuse after 8 minutes and disappeared after 23 minutes (Figure 9B).

Figures 10A - IOC. Images of water penetration of polypropylene fabric treated with an anionic surfactant and a cationic surfactant. A water droplet added to a polypropylene fabric treated with octanoic acid and octadecylamine formed a high contact angle (Figure 10A) and maintained the high contact angle for 4 hours (Figure 10B). After 4.5 hours, the contact angle began to reduce (Figure IOC).

Figures 11 A - 1 IB. Images of drops of vegetable oil deposited onto an untreated nylon fabric (Figure 11 A) and a nylon fabric treated with an anionic surfactant and a cationic surfactant (Figure 1 IB) after 1 minute. Oil droplets begin to spread immediately on untreated nylon fabric (Figure 11 A). A oil droplet did not spread on nylon fabric treated with octanoic acid and octadecylamine (Figure 1 IB) after 1 minute.

Figures 12A - 12B. Images of drops of vegetable oil deposited onto an untreated nylon fabric (Figure 12A) and a nylon fabric treated with an anionic surfactant and a cationic surfactant (Figure 12B) after 2.5 hours. Oil droplets spread and penetrated through untreated nylon fabric (Figure 12A). An oil droplet did not spread or penetrate on nylon fabric treated with octanoic acid and octadecylamine (Figure 12B) after 2.5 hours.

Figure 13. Image of drops of water (left and right) and vegetable oil (center) deposited onto a nylon fabric treated with an octanoic acid and octadecylamine. The treated fabric resisted penetration of the oil for 2 days of continuous exposure. Water droplets were then added showing simultaneous water repellency with high contact angle. The water droplets will evaporate, and fresh water can be added with the same effect.

Figures 14A - 14B. Images of drops of water (left and right) and vegetable oil (center) deposited onto an untreated nylon fabric after 1 minute (Figure 14A) and after 1 hour (Figure 14B). The untreated fabric could not resist the spreading and penetration of the oil and impacted the water repellency. Figure 15. A schematic of an exemplary synthetic fiber production setup that can be used to make an exemplary hydrophobic synthetic textile described herein. (1) is the hopper to hold the chips of the material to be melted such as a polymer (e.g., polyesters, polypropylene, or polyamides such as nylon); (2) are the chips of the material to be melted such as a polymer (e.g., polyesters, polypropylene, or polyamides such as nylon); (3) is the outer housing of the extruder; (4), (5) and (6) are zones 1, 2, and 3 of the extruder that can be set to a desired temperature; (7) is an input port to provide the surfactant that can be in any zone but may be in zone 1 (4) or zone 2 (5) to allow better mixing. Also, the surfactant can be added to the hopper (1) or premixed with the chips (2). (8) is the melted material; (9) is the screw of the extruder that mixes and advances the melted material along the extruder; (10) is the melt pump that pumps the melted material to the spinner; (11) is the spinner which produces fibers from the material; (12) is the fiber of the material; (13) is the quenching chamber that cools the fibers; (14) is the air that cools the fibers; (15) is the spin finish applicator; and (16) is the winding system.

Figures 16A - 16B. A schematic of an exemplary hydrophobic synthetic textile described herein that can repel water and resist oil penetration. (17A) is the fiber or material containing an anionic surfactant; (18A) is the surface of the fiber or material containing the anionic surfactant; (17B) is the fiber or material containing a cationic surfactant; (18B) is the surface of the fiber or material containing the cationic surfactant; (19) is the non-polar or hydrophobic region of the anionic surfactant; (20) is the negatively charged or anionic region of the anionic surfactant; (21) is the positively charged or cationic region of a cationic surfactant; and (22) is the non-polar or hydrophobic region of the cationic surfactant. As can be seen, the anionic surfactant can be present on a surface 18A of said textile (Figure 16A), or a cationic surfactant can be present on a surface 18B of said textile (Figure 16B). A further surfactant having an opposite charge (as compared to the charge present on the surface of said textile) can be attached to said surface.

Figure 17. A schematic of an exemplary hydrophobic cotton (cellulose) textile described herein. (23) is the modified cotton fiber textile material; (24) is a schematic representation of the chemical structure of the modified cellulose that composes the hydrophobic cotton textile; (25) is the anionic carboxylic acid (a non-limiting anionic acid group) that has been added to the native cellulose that comprises the native cotton textile (shown deprotonated); and (26) is a cationic surfactant showing the cationic charged moiety associated with the anionic carboxylic acid.

Figure 18A - 18B. A schematic of an exemplary hydrophilic synthetic textile described herein that can repel oil and resist water penetration. (27) is the fiber or material containing an anionic surfactant; (28) is the surface of the fiber or material containing the anionic surfactant; (29) is the non-polar or hydrophobic region of the anionic surfactant; (30) is the negatively charged region of the anionic surfactant; (31) is the positively charged region of a molecule with a hydrophobic central region and a positively charged region at both ends; (32) is the non-polar or hydrophobic region of a molecule with a hydrophobic central region and a positively charged region at both ends; (33) is the positively charged region of a molecule with a hydrophobic central region and a positively charged region at both ends; (34) is the fiber or material containing a cationic surfactant; (35) is the surface of the fiber or material containing the cationic surfactant; (36) is the non-polar or hydrophobic region of the cationic surfactant; (37) is the positively charged region of the cationic surfactant; (38) is the negatively charged region of a molecule with a hydrophobic central region and a negatively charged region at both ends; (39) is the non-polar or hydrophobic region of a molecule with a hydrophobic central region and a negatively charged region at both ends; and (40) is the negatively charged region of a molecule with a hydrophobic central region and a negatively charged region at both ends. As can be seen, the anionic surfactant can be present on a surface 28 of said textile (Figure 18A), or a cationic surfactant can be present on a surface 35 of said textile (Figure 18B). A further molecule having an opposite charge (as compared to the charge present on the surface of said textile) can be attached to said surface.

DETAILED DESCRIPTION

This document provides textiles (e.g., modified textiles) and methods for making textiles (e.g., modified textiles) such as water-repellent and oil-resistant textiles. A surface of the textile can be treated, modified, or otherwise formed to include hydrophilic charged moieties. For example and without limitation, the hydrophilic charged moieties can provide a first layer of chemical functionalization that is hydrophilic (e.g., which can resist oil penetration in the modified textile). In turn, a molecule having an opposite charge can be used to interact with said hydrophilic charged moieties. This molecule can include one or more charged moieties and a hydrophobic moiety. For example and without limitation, this surfactant or other molecule can include an opposite charge (as compared to the hydrophilic charged moieties at the surface of the textile), in which such charge-based interactions provide a second layer that includes hydrophobic moieties. The second layer can be considered to be a hydrophobic layer that overlies the first hydrophilic layer. For example, such layers can provide a textile having water repellency and oil resistance, wherein an overlying hydrophobic surface (or hydrophobic layer) repels water and an underlying hydrophilic layer resists penetration of oil.

The hydrophilic layer can be formed by interactions between the hydrophilic charged moieties at a surface of the textile and the hydrophilic charged moieties provided by a surfactant or other molecule having charged moieties. In some embodiments, the hydrophilic charged moieties at a surface of the textile include negatively charged or anionic regions or moieties, and the surfactants or other molecule can include positively charged or cationic regions or moieties (see, e.g., Figures 16A, 17, and 18A). In some embodiments, the hydrophilic charged moieties at a surface of the textile include positively charged or cationic regions or moieties, and the surfactants or other molecule can include negatively charged or anionic regions or moieties (see, e.g., Figures 16B and 18B). For any charged moiety herein, the opposing charge can be implemented and are encompassed by textiles and methods herein.

This document provides modified textiles (e.g., water-repellent textiles) as well as methods for modifying textiles to alter one or more properties of the textiles. In some cases, a textile can be modified to be more water-repellent. For example, a textile (e.g., a textile containing one or more cellulose fibers) can be modified to have one or more charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent). In some cases, a textile containing one or more cellulose fibers can be modified such that at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) are converted to charged (e.g., negatively charged) moieties (e.g., anionic acid groups), and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile (e.g., a textile containing one or more synthetic fibers) can be produced to have one or more charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent). In some cases, a textile containing one or more synthetic fibers can be produced in the presence of a first surfactant (e.g., an anionic surfactant such as a fatty acid) (e.g., and thereby incorporating the first surfactant), such that charged (e.g., negatively charged) regions of the first surfactant are present on the surface of the textile, and the textile can subsequently be contacted with a second surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic (e.g., more water-repellent and/or oil-resistant).

This document also provides textiles having a surface functionalization or a surface coating of one or more charged (e.g., negatively charged) moieties, and having a surfactant (e.g., a cationic surfactant) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the charged moieties. For example, a textile (e.g., a textile containing one or more cellulose fibers) can include one or more negatively charged moieties on its surface, and can have a cationic surfactant attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the negatively charged moieties. For example, a textile (e.g., a textile having one or more synthetic fibers) can have (e.g., can be engineered to have) one or more charged (e.g., negatively charged) moieties on its surface, and can have a surfactant (e.g., a cationic surfactant) attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the charged moieties. In some cases, a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached (e.g., electrostatically attached, ionically attached, or covalently attached) to the negatively charged moieties can have the ability to repel water and/or to resist oil.

In some cases, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be more hydrophobic (e g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties). For example, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be more water-repellent (e.g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties). Water-resistance or water-repellency can be determined by measuring contact angles or other methods to determine wetting or wettability.

In some cases, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be more conductive (e.g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties). For example, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be more anti-static (e.g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties). Anti-static characteristics can be determined by measuring conductivity or other methods to determine conduction.

In some cases, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be more easily dyed or may consume less dyes during a dying process (e.g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties).

In some cases, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be impact wear (e.g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties).

In some cases, the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties) can be improve washability or improve the ability to remove dirt or stains (e.g., as compared to a textile that lacks a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the charged moieties).

As used herein, a “surfactant” refers to a molecule that includes a hydrophobic (e.g., non-polar) region and a hydrophilic (e.g., polar) region. For example, a surfactant can include a hydrophobic tail and a hydrophilic head. In some cases, a surfactant can be non-toxic. For example, a surfactant can be edible. In some cases, a surfactant can be biodegradable. In some cases, a surfactant does not contain any fluorine. In some cases, a surfactant can be an anionic surfactant (e.g., can include one or more negatively charged functional groups in its hydrophilic region).

The term “anionic surfactant” means a surfactant comprising, as ionic or ionizable groups, only anionic groups. These anionic groups include, without limitation, hydroxyls, sulfates, sulfonates, phosphates, and carboxylates, as well as charged forms thereof and salt forms thereof. For example, anionic groups can include -CO2H , -CCh', -SO3H , -S f, - OSO3H, -OSO3; -O2PO2H, and - O2PO2² ’. The anionic surfactant can include a hydrophobic region (e.g., a C8 - C30 hydrocarbon based chain). Anionic surfactants may also include alkylbenzene sulfonates, alkyl sulfonates, alkyl sulfates, fatty alcohol sulfates, polyoxyethylene fatty alcohol ether sulfates, a-olefin sulfonate, polyoxyethylene fatty alcohol phosphates ether, alkyl succinate sulfonate salts, amino alcohol alkylbenzene sulfonates, alkylphenol sulfonate, and polyoxyethylene monolaurate. Specific examples include, without limitation, include the saturated and unsaturated fatty acids such as octanoic acid (also referred to as caprylic acid) and sodium stearate, sodium octyl sulfate, sodium dodecyl sulfate, sarcosinates (e.g., sodium lauroyl sarcosinate and sodium oleyl sarcosinate), and salts forms thereof (e.g., alternative salt forms of any of these).

The term “cationic surfactant” means a surfactant comprising, as ionic or ionizable groups, only cationic groups. These cationic groups include, without limitation, ammonium, quaternary ammonium, iminium, guanidine, guanidinium, as well as charged forms thereof and salt forms thereof. For example, anionic groups can include -NH2, -NH3⁺, -N(CH3)3⁺, -NHC(NH2)NH2, or -NHC(NH2⁺)NH2. The cationic surfactant can include a hydrophobic region (e.g., a C8 - C30 hydrocarbon based chain). The cationic surfactant may be chosen from optionally polyoxyalkylenated, primary, secondary, or tertiary fatty amines, or salts thereof, and quaternary ammonium salts, and a mixture thereof. The fatty amines generally comprise at least one C8 - C30 hydrocarbon based chain. Specific examples, without limitation, include octadecylamine, lauric arginate, nonylamine, dodecyltrimethylammonium chloride, N-hexadecyltrimethylammonium chloride, trimethyl stearylammonium chloride, cetrimide, and salts forms thereof (e.g., alternative salt forms of any of these). In some cases, a surfactant can be a zwitterionic or amphoteric surfactant (e.g., can include both an anionic moiety and a cationic moiety). The charges on these moieties can either be permanent or dependent on pH. The cationic moiety is often an amine or a quaternary ammonium cation, where the anionic moiety is often a carboxylic, sulfuric, or phosphoric acid (or esters of these). Examples of zwitterionic surfactants that can be used as described herein include, without limitation, cocamidopropyl betanine, amidosulfobetaine- 16, lauryl-N,N-(dimethylammonio)butyrate, lauryl-N,N-(dimethyl)-glycinebetaine, hexadecyl phosphocholine, lauryl-N,N-(dimethyl)-propanesulfonate, lauryldimethylamine N- oxide, and phospholipids including phosphatidylcholine and phosphatidylethanolamine.

A surfactant can be attached to a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) by any appropriate type of attachment. For example, a surfactant (e.g., a cationic surfactant) can bond (e.g., can electrostatically bond, can ionically bond, or can covalently bond) to charged moieties (e.g., negatively charge moieties) present on a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties).

In some cases, a surfactant can be present in a solution (e.g., an aqueous solution). For example, a surfactant can be present in an aqueous solution having a surfactant concentration that is less than a critical micelle concentration of the surfactant in the aqueous solution. For example, a surfactant can be present in an aqueous solution having little to no alcohol (e.g., a 100% aqueous solution).

In cases where a surfactant (e.g., a cationic surfactant) is attached to charged moieties (e.g., negatively charged moieties) present on a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) by electrostatic bonds, the electrostatic bonds can be converted into covalent bonds. Any appropriate method can be used to convert an electrostatic bond into a covalent bond. In some cases, electrostatic bonds can be converted to covalent bonds as described elsewhere (see, e.g., Kast et al., Biomaterials, 22:2345-2352 (2001); and Kast et. al., Ini. J. Pharmaceut., 256: 183-189 (2003)). In some cases, the cationic surfactant may be replaced with a molecule that is not a surfactant, but rather a molecule containing a hydrophilic cationic charged moiety on either end and a hydrophobic region in the middle. Cationic examples include 1,N - diamine (e.g., a l,N-diamino-Ci-N alkane, wherein N can be from 8-30) which can be, for example, 1,8- diaminooctane or 1,12-diaminododecane, which can include quaternary forms thereof. Nonlimiting quaternary forms can include e.g., a l,N-diammonium-Ci-N alkane, wherein N can be from 8-30; l,N-ditrimethylammonium-Ci-N alkane, wherein N can be from 8-30; and the like. In cases where the textile surface is imparted a cationic moiety and a molecule containing a hydrophilic anionic charged moiety on either end and a hydrophobic region in the middle is desired, anionic examples include 1,N - alkanedioic acid (e.g., a 1,N-CI-N alkanedioic acid, wherein N can be from 8-30) which can be, for example, 1,8-octanedioic acid, 1,12-dodecanedioic acid, or other versions of this molecule with different carbon chain lengths between the anionic carboxylic acid groups. Such anionic examples can include anionic forms thereof, such as deprotonated forms thereof or salt forms thereof.

A textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) can be any appropriate type of textile. For example, textiles may include woven or non-woven fibers. For example, a textile provided herein can include any one or more types of fibers (e g., one or more natural fibers and/or one or more synthetic fibers). In some cases, a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) can contain one or more cellulose fibers. A textile containing one or more cellulose fibers can contain natural cellulose fibers, regenerated cellulose fibers, and/or manufactured cellulose fibers. In some cases, a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) can contain one or more proteinaceous fibers (e.g., as in cashmere, mohair, pashmina, wool, silk, or a combination of any of these). For example and without limitation, proteinaceous fibers may be so modified to increase the content of cationic or anionic charges to accept the anionic or cationic surfactant or molecule. In some cases, a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) can contain one or more synthetic fibers. For example, a textile containing synthetic fibers can include one or more synthetic polymeric fibers (e.g., polyesters, polyamides such as nylon and polypropylene). Examples of textiles that can have a surface coating of one or more negatively charged moieties, and can have a cationic surfactant attached to the negatively charged moieties) include, without limitation, cotton, bamboo, coir, flax (linen), hemp, jute, rayon, viscose, lyocell, modal, nylon, polyester, polypropylene, kevlar, microfiber, modacrylic, and spandex. Polymers herein can include homopolymers and copolymers, such as nylon 6 (polyamide 6), nylon-6/6 (polyamide-66), nylon-6/10, and nylon-4/6.

When a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) contains one or more cellulose fibers, the textile can include any appropriate amount of cellulose fibers. In some cases, a modified textile provided herein can include at least 10% cellulose fibers. In some cases, a textile (e.g., a modified textile) provided herein can include from about 10% cellulose fibers to about 100% cellulose fibers.

When a textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) contains one or more cellulose fibers, the textile containing one or more cellulose fibers can have one or more charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic thereby rendering the surface of the textile more water-repellent. In some cases, a textile containing one or more cellulose fibers can be modified such that at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) are converted to charged (e g., negatively charged) moieties (e.g., anionic acid groups), and the textile can subsequently be contacted with a cationic surfactant (e.g., lauric arginate) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile containing one or more cellulose fibers can be modified such that at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) are converted to charged (e g., negatively charged) moieties (e.g., anionic acid groups), and the textile can subsequently be contacted with a cationic surfactant (e.g., lauric arginate) under conditions where one or more positively charged functional groups present on the hydrophilic region of the cationic surfactant can bond (e.g., can electrostatically bond, can ionically bond, or can covalently bond) to the one or more negatively charged moieties present on the textile to render the surface of the textile more hydrophobic (e.g., more water-repellent). In cases where a cationic surfactant contains one or more amine groups (e.g., octadecylamine, lauric arginate, or nonylamine), one or more positively charged functional groups present on the hydrophilic region of the cationic surfactant can covalently bond or attach (e.g., via formation of an amide bond) to the one or more negatively charged moieties present on the textile to render the surface of the textile more hydrophobic (e.g., more water-repellent).

A textile provided herein (e.g., a textile having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties) can have any appropriate charged moiety on its surface. In some cases, a textile containing one or more cellulose fibers can have one or more negatively charged moieties on its surface. Examples of negatively charged moieties that a textile containing one or more cellulose fibers can have on its surface include, without limitation, anionic acid groups that are formed by converting negatively charged surface hydroxyl groups. Examples of anionic acid groups can include moieties having CO2H , -CCh’, or others described herein. In some cases, a textile containing one or more cellulose fibers can have one or more positively charged moieties on its surface. Examples of positively charged moieties that a textile containing one or more cellulose fibers can have on its surface as described herein include, without limitation amines (e.g., -NH2, -NH3 , or -NH-(CH2)2-NH2) and quaternary ammonium groups (e.g., -N(CH3)3⁺).

Any appropriate method can be used to make the textiles provided herein (e.g., textiles having a surface coating of one or more negatively charged moieties, and having a cationic surfactant attached to the negatively charged moieties). In some cases, a textile containing one or more cellulose fibers can be contacted with an acid to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to negatively charged moieties, and can subsequently contacted with a cationic surfactant such that one or more positively charged functional groups present in a hydrophilic region of the cationic surfactant can form a bond or attachment with the negatively charged moieties to render the surface of the textile more hydrophobic. In some cases, a textile containing one or more synthetic fibers can be produced in the presence of an anionic surfactant (e.g., and thereby incorporating the anionic surfactant), such that negatively charged regions of the anionic surfactant are present on a surface of the textile, and can subsequently be contacted with a cationic surfactant such that one or more positively charged functional groups present in a hydrophilic region of the cationic surfactant can form a bond or attachment with the negatively charged hydroxyl groups to render the surface of the textile more hydrophobic.

In some cases, a textile containing one or more cellulose fibers can be contacted with an acid to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fibers to charged (e.g., negatively charged) moieties. Any appropriate method can be used to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to negatively charged moieties. In some cases, alkalization and etherification (e.g., alkalization followed by etherification) can be used to convert at least some of the functional groups (e.g., hydroxyl groups) present in a cellulose fiber(s) of a textile containing one or more cellulose fibers to one or more charged (e.g., negatively charged) moieties. For example, at least some of the hydroxyl groups present in the cellulose fiber(s) of a textile containing can be converted to negatively charged carboxylate groups or positively charged amine or ammonium groups. For example, a textile containing one or more cellulose fibers can be contacted with one or more acids to convert at least some of the hydroxyls on the cellulose fibers in the textile to negatively charged moieties, such as anionic acid groups. Examples of acids that can be contacted with a textile containing one or more cellulose fibers as described herein include, without limitation, chloroacetic acid or a salt thereof, which is typically applied in conjunction with sodium hydroxide in ethanol (e.g., as described in U.S. Pat. No. 4,410,694, which is incorporated herein by reference in its entirety). Other acids can be employed, such as diacids including but not limited to phthalic acid, succinic acid, and maleic acid. For example, a textile containing one or more cellulose fibers can be contacted with one or more silane compounds having an anionic moiety or a cationic moiety, in which silane can react with at least some of the hydroxyls on the cellulose fibers in the textile to provide negatively charged moieties, such as anionic acid groups, or positively charged moieties, such as cationic amino or cationic ammonium groups. Examples of silanes that can be contacted with a textile containing one or more cellulose fibers as described herein include, without limitation, a carboxysilane (e.g., carboxyethyltriethoxysilane) to provide an anionic moiety or an aminosilane (e.g., y- aminopropyltriethoxysilane (APS) or N-(2-aminoethyl)-3-aminopropyltrimethoxysilane) to provide a cationic moiety, which is typically applied to a surface or co-polymerized with a polymer.

In one non-limiting example, the textile containing one or more cellulose fibers can include one or more of the following:

(1) (Dehydration step) Dried cotton soaked in 100% ethanol for about 5 minutes to about 60 minutes (e.g., about 40 min), at about 20 degrees C to about 40 degrees C (e.g., at room temperature).

(2) (Alkalization step) Cotton then placed into a solution of 100: 10 (v/v) ethanol:NaOH for about 40 minutes while stirring. Range could be about 100: 1 to about 100:25 for about 5 minutes to about 60 minutes.

(3) (Etherification step) To solution in (2), add 50% NaOH in DI water so that the final solution is about 100:X(above): l to about 100:X(above):20 (e.g., about 100:X:6), and heat to about 30 degrees C to about 50 degrees C (e.g., about 40 degrees C, which can optionally include stirring).

(4) Once the temperature reaches about 30 degrees C to about 50 (e.g., about 40 degrees C), add chloroacetic acid solution (formed by dissolving 1.758 g of chloroacetic acid into 2 mL of ethanol) so that the final concentration of the solution is about 100:X:Y:(l-20), including about 100:(l-25):(l-20):(l-20) (e.g., about 100: 10:6:8). Maintain temperature at about 40 degrees C to about 55 degrees C (e.g., about 50 degrees C) for about 5 minutes to about 60 minutes (e.g., about 30 minutes).

(5) Rinse with water until pH is about 6.5 to about 7.5 (e.g., pH of about 7).

(6) Submerge cotton into a water solution where the pH has been adjusted to about 4 to about 6 (e.g., pH of about 5) using an acid (e.g., such as formic acid) of about 0.01% to about 0.5% (e.g., about 0.15%) of lauric arginate, nonylamine, or octadecylamine in water. Soak while stirring for about 10 minutes to about 120 minutes (e.g., about 60 minutes). Any amine terminated alkyl chain would be acceptable where the number of carbons range from about 6 to about 30. In any case, the concentration of the surfactant in solution should be generally below the critical micelle concentration.

(7) Rinse with water.

(8) Dry, if desired.

When a textile containing one or more cellulose fibers is contacted with one or more acids to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, the textile can be first contacted with one or more alcohols for any appropriate amount of time. In some cases, the one or more alcohols can be stirred for at least some of the time that a textile containing one or more cellulose fibers is in contact with the one or more alcohols. In some cases, a textile containing one or more cellulose fibers can be contacted with one or more alcohols for from about 5 minutes to about 60 minutes (e.g., for about 40 minutes)

When a textile containing one or more cellulose fibers is then contacted with one or more alcohols and one or more bases to perform alkalization to convert at least some of the functional groups (e g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, the textile can be contacted with one or more alcohols and one or more bases at any appropriate temperature. In some cases, a textile containing one or more cellulose fibers can be contacted with one or more alcohols at from about 20 °C to about 40 °C. For example, a textile containing one or more cellulose fibers can be contacted with one or more alcohols and bases at room temperature.

When a textile containing one or more cellulose fibers is contacted with one or more alcohols and one or more acids to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, the textile can be contacted with one or more alcohols at any appropriate temperature. In some cases, a textile containing one or more cellulose fibers can be contacted with one or more alcohols at from about 20 °C to about 40 °C. For example, a textile containing one or more cellulose fibers can be contacted with one or more alcohols at room temperature. When a textile containing one or more cellulose fibers is contacted with one or more alcohols and contacted with one or more acids to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, the textile can be contacted with the one or more acids for any appropriate amount of time. In some cases, the one or more acids can be stirred for at least some of the time that a textile containing one or more cellulose fibers is in contact with the one or more acids. In some cases, a textile containing one or more cellulose fibers can be contacted with one or more acids for from about 5 minutes to about 60 minutes (e g., for about 30 minutes).

When a textile containing one or more cellulose fibers is contacted with one or more alcohols and contacted with one or more acids to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, the textile can be contacted with the one or more acids at any appropriate temperature. In some cases, a textile containing one or more cellulose fibers can be contacted with one or more acids at from about 40 °C to about 55 °C (e.g., at about 50 °C).

When a textile containing one or more cellulose fibers is contacted with one or more alcohols and contacted with one or more acids to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, the textile can have any appropriate pH. In some cases, a textile containing one or more cellulose fibers that has been contacted with one or more acids can have a pH of from about 6.5 to about 7.5 (e.g., about pH 7.0).

In some cases when a textile is contacted with one or more alcohols, the alcohol(s) can include one or more hydroxides. In some cases, a hydroxide can be in the form of a salt. Examples of hydroxide salts that can be used to form a solution containing one or more hydroxides that can be contacted with a textile containing one or more cellulose fibers as described herein include, without limitation, sodium hydroxide (NaOH) or potassium hydroxide (KOH).

When a textile containing one or more cellulose fibers is contacted with one or more alcohols and contacted with one or more acids to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) to charged (e.g., negatively charged) moieties, any appropriate amount of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) can be converted to charged (e.g., negatively charged) moieties. In cases where hydroxyl groups present in cellulose fibers in a textile containing one or more cellulose fibers are modified to be negatively charged acid groups (e.g., carboxylic acid or carboxylate moieties), at least about 0.1% of the hydroxyl groups present in cellulose fibers in a textile containing one or more cellulose fibers can be converted to negatively charged hydroxide anions. For example, a textile containing one or more cellulose fibers can have a degree of substitution (DS) from about 0.05 to about 2 converted to charged moieties (e.g., negatively charged acid groups), in which 2 indicates that 2 of the 3 hydroxyl groups on the glucan (sugar) subunit of cellulose (e.g., a DS from about 0.5 to about 1, or a DS of about 1).

In some cases, a textile containing one or more cellulose fibers that has a surface coating of one or more negatively charged moieties, and has a cationic surfactant attached to the charged moieties can be made as described in Example 1.

Any appropriate method can be used to convert at least some of the functional groups (e.g., hydroxyl groups) present in the cellulose fiber(s) of a textile containing one or more cellulose fibers to positively charged moieties. For example, a textile containing one or more cellulose fibers can be contacted with one or more ammonium-containing compounds to convert at least some of the hydroxyls on the cellulose fibers in the textile to positively charged moieties. Examples of ammonium-containing compounds include 3-chloro-2- hydroxypropyltrimethylammonium chloride (CHPTAC), which forms an epoxide that can undergo nucleophilic substitution by way of a hydroxyl group on cellulose, thereby installing the trimethylammonium group on cellulose. For example, a textile containing one or more cellulose fibers can be contacted with an amino silane to convert at least some of the hydroxyls on the cellulose fibers in the textile to positively charged moieties. Examples of aminosilanes include aminopropyltri ethoxy silane, in which the alkoxysilane group reacts with a hydroxyl group on cellulose, thereby installing the amino group on cellulose; or N-(2- aminoethyl)-3-aminopropylmethyldimethoxysilane, in which the alkyldialkoxysilane group reacts with a hydroxyl group on cellulose, thereby installing the N-(2-aminoethyl)-3- aminopropyl group on cellulose.

To a textile containing one or more cellulose fibers to positively charged moieties, an anionic surfactant can be attached. For example, the anionic surfactant can be a saturated or unsaturated fatty acid containing about 6 to about 30 carbons, such as sodium stearate, sodium octyl sulfate, or sodium dodecyl sulfate. In some non-limiting embodiments, the modified textile can provide water repellency and oil resistance.

To a textile containing one or more cellulose fibers to positively charged moieties, a molecule can be attached, in which the molecule can include a hydrophilic anionic group on either end of a molecule with a hydrophobic center region such as dodecanedioic acid or others herein. This would be to provide oil repellency and water resistance.

A textile containing one or more cellulose fibers that has one or more charged (e.g., negatively charged) moieties on its surface can be contacted with any appropriate surfactant (e g., to render the surface of the textile more hydrophobic thereby rendering the surface of the textile more water-repellent). In some cases, a textile containing one or more cellulose fibers can have one or more negatively charged moieties on its surface, and can be contacted with a cationic surfactant. For example, a textile containing one or more cellulose fibers and having one or more negatively charged moieties on its surface can be contacted with a cationic surfactant under conditions where one or more positively charged functional groups present on the hydrophilic region of the cationic surfactant can bond or attach (e g., can electrostatically bond, can ionically bond, or can covalently bond) to the one or more negatively charged moieties present on the textile to render the surface of the textile more hydrophobic (e.g., more water-repellent). Examples of cationic surfactants that can contacted with a textile containing one or more cellulose fibers as described herein include, without limitation, lauric arginate, nonylamine, dodecyltrimethylammonium chloride, N- hexadecyltrimethylammonium chloride, trimethylstearylammonium chloride, or cetrimide.

In some cases, a textile containing one or more cellulose fibers can have one or more positively charged moieties on its surface, and can be contacted with an anionic surfactant. For example, a textile containing one or more cellulose fibers and having one or more positively charged moieties on its surface can be contacted with an anionic surfactant under conditions where one or more negatively charged functional groups present on the hydrophilic region of the anionic surfactant can bond or attach (e.g., can electrostatically bond, can ionically bond, or can covalently bond) to the one or more positively charged moieties present on the textile to render the surface of the textile more water-repellent and/or oil-resistant. Examples of anionic surfactants that can contacted with a textile containing one or more cellulose fibers as described herein include, without limitation, a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

In some cases, a textile containing one or more synthetic fibers can have (e.g., can be engineered to have) one or more charged (e.g., negatively charged) moieties on its surface, and the textile can subsequently be contacted with a surfactant (e.g., a cationic surfactant) to render the surface of the textile more hydrophobic thereby rendering the surface of the textile more water-repellent. In some cases, a textile containing one or more synthetic fibers can be produced in the presence of a first surfactant (e.g., an anionic surfactant such as a fatty acid) (e.g., and thereby incorporating the first surfactant), such that charged (e.g., negatively charged) regions of the first surfactant are present on the surface of the textile, and the textile can subsequently be contacted with a cationic surfactant (e.g., lauric arginate) to render the surface of the textile more hydrophobic (e.g., more water-repellent). For example, a textile containing one or more synthetic fibers can be produced in the presence of an anionic surfactant (e.g., a fatty acid) (e.g., and thereby incorporating the anionic surfactant), such that negatively charged regions of the anionic surfactant are present on the surface of the textile, and the textile can subsequently be contacted with a cationic surfactant (e.g., lauric arginate) under conditions where one or more positively charged functional groups present on the hydrophilic region of the cationic surfactant can bond or attach (e.g., can electrostatically bond, can ionically bond, or can covalently bond) to the one or more negatively charged moieties present on the textile to render the surface of the textile more hydrophobic (e.g., more water-repellent). In cases where a cationic surfactant contains one or more amine groups (e.g., as in a fatty amine or other cationic surfactants described herein), one or more positively charged functional groups present on the hydrophilic region of the cationic surfactant can covalently attach (e.g., via formation of an amide bond) to the one or more negatively charged moieties present on the textile to render the surface of the textile more hydrophobic (e.g., more water-repellent and/or oil-resistant).

A textile containing one or more synthetic fibers can be produced to have any appropriate charged moiety on its surface. In some cases, a textile containing one or more synthetic fibers can be modified to have one or more negatively charged moieties on its surface. Examples of negatively charged moieties that a textile containing one or more synthetic fibers can be produced to have on its surface as described herein include, without limitation, negatively charged groups (e.g., anionic acid groups). Examples of anionic acid groups can include moieties having CO2H , -CO?’, or others described herein. In some cases, a textile containing one or more synthetic fibers can have one or more positively charged moieties on its surface. Examples of positively charged moieties that a textile containing one or more synthetic fibers can have on its surface as described herein include, without limitation, amines (e.g., -NH2, -NH or -NH-(CH2)2-NH2) and quaternary ammonium groups (e.g., -N(CH.3)3⁺). Any methods or processes described herein for cellulose can be adapted for use with a textile containing one or more synthetic fibers.

Any appropriate method can be used to produce a textile containing one or more synthetic fibers having one or more charged (e.g., negatively charged) moieties on a surface of the textile. In some cases, a textile containing one or more synthetic fibers can be produced in the presence of a first surfactant (e.g., an anionic surfactant such as a fatty acid) (e.g., and thereby incorporating the first surfactant), such that charged (e.g., negatively charged) regions of the first surfactant are present on the surface of the textile. For example, a surfactant can be added to a system (e.g., an extruder) for making a textile containing one or more synthetic fibers such that the surfactant enters the synthetic fibers forming the textile and charged (e.g., negatively charged) regions of the surfactant are present on the surface of the textile. For example, a surfactant can be added to melted synthetic fibers in a system (e g., an extruder) for making a synthetic textile such that the surfactant enters the synthetic fibers forming the textile and charged (e.g., negatively charged) regions of the surfactant are present on the surface of the textile. For example, an anionic surfactant (e.g., a fatty acid) can be added to an extruder together with one or more synthetic (e.g., nylon, polyester, and/or polypropylene) fibers such that the anionic surfactant and synthetic fibers mix and at least some of the negative charged regions of the anionic surfactant are present on a surface of the textile.

Another method that can be used to produce a textile containing one or more synthetic fibers having one or more charged (e.g., negatively charged) moieties on the surface of the textile includes diffusing the non-polar hydrophobic region of a surfactant into the surface of an already made textile by exposing the surface of the textile to the surfactant and raising the temperature to allow the diffusion process to occur. Once cooled, the non- polar hydrophobic region of the surfactant will be anchored in the hydrophobic textile fiber. The hydrophilic polar charged region of the surfactant will have difficulty diffusing into the hydrophobic non-polar textile as a result of the difference in polarities. This will position polar charged (e.g., negatively charged) moieties on the surface of the synthetic fiber. For example, synthetic fibers can be exposed to an anionic surfactant and then have the temperature raised such that the hydrophobic non-polar region of the surfactant enters into the surface of the synthetic fibers forming the textile positioning the charged (e.g., negatively charged) regions of the surfactant on the surface of the textile. For example, an anionic surfactant (e.g., a fatty acid) can be so positioned on the surface of one or more synthetic (e.g., nylon, polyester, and/or polypropylene) fibers such that the polar anionic region of the surfactant is present on a surface of the textile.

When a textile containing one or more synthetic fibers is produced in the presence of one or more surfactants, the surfactants can be added to any appropriate system for producing a textile containing one or more synthetic fibers. Examples of systems that can be used to produce a textile containing one or more synthetic fibers and that can be used to produce a textile containing one or more synthetic fibers in the presence of one or more surfactants (e.g., and thereby incorporating the one or more surfactants) as described herein include, without limitation, extruders, electrospinning apparatuses, and the like. Figure 15 shows an exemplary synthetic fiber production setup that can be used to make an exemplary synthetic textile described herein. One or more surfactants can be applied during or after extruding or electrospinning.

When a textile containing one or more synthetic fibers is produced in the presence of one or more surfactants, the surfactants can be added to a system for producing a textile containing one or more synthetic fibers at any appropriate temperature. In some cases, a textile containing one or more synthetic fibers can be produced in the presence of one or more surfactants (e.g., and thereby incorporating the one or more surfactants) at a temperature that is high enough to melt the one or more synthetic fibers. In some cases, the one or more surfactants are contained or incorporated within the one or more synthetic fibers, such that charged (e.g., negatively charged) regions of the first surfactant are present on the surface of the textile. For example, a textile containing one or more synthetic fibers such as nylon and polyester can be produced in the presence of one or more surfactants (e.g., and thereby incorporating the one or more surfactants) at from about 120 °C to about 290 °C. For example, a textile containing one or more synthetic fibers such as nylon and polyester can be produced in the presence of one or more surfactants (e.g., and thereby incorporating the one or more surfactants) at from about 120 °C to about 290 °C when electrospinning is employed.

In some cases, a textile containing one or more synthetic fibers can be produced to have one or more charged (e.g., negatively charged) moieties on its surface as described in Example 2.

A textile containing one or more synthetic fibers that is produced to have one or more charged (e.g., negatively charged) moieties on its surface can be contacted with any appropriate surfactant (e.g., to render the surface of the textile more hydrophobic thereby rendering the surface of the textile more water-repellent). In some cases, a textile containing one or more synthetic fibers can be produced to have one or more negatively charged moieties on its surface, and can be contacted with a cationic surfactant. For example, a textile containing one or more synthetic fibers can be produced in the presence of an anionic surfactant to have one or more negatively charged moieties on its surface can be contacted with a cationic surfactant under conditions where one or more positively charged functional groups present on the hydrophilic region of the cationic surfactant can bond or attach (e.g., can electrostatically bond, can ionically bond, or can covalently bond) to the one or more negatively charged moieties present on the textile to render the surface of the textile more hydrophobic (e.g., more water-repellent). Examples of cationic surfactants that can be contacted with a textile containing one or more cellulose fibers and produced to have one or more negatively charged moieties on its surface include, without limitation, a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethylammonium chloride or another salt thereof, trimethylstearylammonium chloride or another salt thereof, and cetrimide.

In some cases, a textile containing one or more synthetic fibers can be produced to have one or more positively charged moieties on its surface, and can be contacted with an anionic surfactant. For example, a textile containing one or more synthetic fibers and produced in the presence of a cationic surfactant to have one or more positively charged moieties on its surface can be contacted with an anionic surfactant under conditions where one or more negatively charged functional groups present on the hydrophilic region of the anionic surfactant can bond or attach (e.g., can electrostatically bond, can ionically bond, or can covalently bond) to the one or more positively charged moieties present on the textile to render the surface of the textile more water-repellant and/or oil-resistant. Examples of anionic surfactants that can be contacted with a textile containing one or more cellulose fibers as described herein include, without limitation, saturated fatty acids, unsaturated fatty acids, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

The invention will be further described in the following examples, which do not limit the scope of the invention described in the claims.

EXAMPLES

Example 1: Functionalization of Cotton or Cotton-Containing Textiles

This Example describes the functionalization of cotton-containing textiles by anchoring an anionic fatty acid surfactant to the fabric, and then treating the fabric with a cationic surfactant.

Materials

Sample A:

Sample A was a 100% cotton woven fabric that was dyed black.

Sample B:

Samples B was a 50% cotton - 50% recycled polyester woven fabric that was undyed (e.g., was white).

Process

1. Sample preparation

As an optional step, a cellulose containing fabric was placed into 100% ethanol at room temperature overnight. Without wishing to be limited by mechanism, this optional step may be employed to dehydrate the sample, which may improve reaction efficiency in some non-limiting instances. Dehydration time may be optimized for the particular fabric being employed, in which such time can be overnight

2. Sample alkalization

Immerse fabric into a solution where the ratio of its contents are as follows: 100 mL ethanol with 10 mL 30% NaOH at room temperature for 40 minutes with stirring.

3. Sample etherification a. Following the above solution contents: add 6 mL 50% NaOH into the solution from step 2 and heat to 40 degree C while stirring. b. Once the temperature reaches 40 degrees C, add 8 mL chloroacetic acid solution (prepared by dissolving every 1.758 g chloroacetic acid into 2 mL ethanol) and keep at 50 degree C for 30 minutes while stirring. c. Rinse the sample with water until pH reaches 7.0.

4. Functionalization with lauric arginate a. Following the above solution contents: Add 100 mL 0.15% LAE, stir for 4 hours. b. Rinse the sample with water.

5. Final products a. Dry sample as desired.

In this process, ethanol content may be reduced or replaced with water. This may reduce the surface modification.

Results

Sample A: Before treatment, water penetrated in less than 1 minute (Figure 1A). After treatment, water did not penetrate for 15 minutes. Surface contact angle increases substantially. Color remained intact (Figure IB).

Sample B: Before treatment. Water penetrated in less than 1 minute (Figure 2A). After treatment. Water did not penetrate for 15 minutes. Surface contact angle increased substantially. No color imparted onto sample (Figure 2B). Example 2: Functionalization of Nylon and Polypropylene Textiles

Materials

Sample C:

Dyed nylon fabric.

Sample D:

Dyed polypropylene fabric.

Process

1. Nylon or polypropylene fabric was soaked in an octanoic solution (4 g/L acid with IL deionized (DI) water) for 3h. A range of concentrations may also be employed, such as e.g., 0.1 g/L to 20 g/L.

2. Excess solution was allowed to drain from the fabric for 2 minutes.

3. Nylon or polypropylene fabric was thermally treated at 120 degrees C for 2 minutes.

4. Nylon or polypropylene fabric was washed with water 3 times for 1 minute each.

5. Nylon or polypropylene fabric was oven dried at 70 degrees C for 2 minutes.

6. Nylon or polypropylene fabric was soaked in a solution of 1 -octadecylamine hydrochloride (3 g octadecyl -amine with 100 mL ethanol) for 2 hours.

7. Nylon or polypropylene fabric was thermally treated at 120 degrees C for 2 minutes.

8. Nylon or polypropylene fabric was washed with acetone 3 times for 1 minute each.

9. Nylon or polypropylene fabric was oven dried at 70 degrees C for 2 minutes.

Results

Sample C: Treating Nylon

Water droplets formed on untreated nylon fabric (Figure 3A) but started to diffuse after 34 minutes and completely disappeared after 45 minutes (Figure 3B).

When nylon fabric was treated with only octanoic acid, a water droplet formed on the treated nylon fabric (Figure 4A) but started to diffuse after 48 seconds (Figure 4B).

When nylon fabric was treated with only octadecylamine, a water droplet formed on the treated nylon fabric (Figure 5A), but the contact angle began to reduce and the water droplet started to diffuse after 38 minutes (Figure 5B). When nylon fabric was treated with both octanoic acid and octadecylamine, a water droplet formed on the treated nylon fabric (Figure 6A). The water droplet not diffuse into the fabric and maintained a contact angle of over 90 degrees for at least 270 minutes (Figures 6B and 6C).

Sample D: Treating Polypropylene

Water droplets formed on untreated polypropylene fabric (Figure 7A) and maintained a high contact angle for over 4 hours. The contact angle started to reduce, and the water started to diffuse after 5 hours (Figure 7B).

When polypropylene fabric was treated with octanoic acid, a water droplet did not form on the surface of the treated polypropylene fabric (Figure 8A). The water droplet diffused completely within minutes, and after 45 minutes no trace of the water could be observed (Figure 8B). These results demonstrate that there was minimal hydrophobic feature on the surface.

When polypropylene fabric was treated with octadecylamine, a water droplet formed on the treated polypropylene fabric with a high contact angle (Figure 9A). The water droplet started to diffuse after 8 minutes and disappeared after 23 minutes (Figure 9B).

When polypropylene fabric was treated with octanoic acid and octadecylamine, a water droplet formed on the treated polypropylene fabric with a high contact angle (Figure 10A). The high contact angle was maintained for 4 hours (Figure 10B). After 4.5 hours, the contact angle began to reduce (Figure 10C).

Example 3: Water-Repellency and Oil-Repellency of Functionalized Nylon Textiles

Dyed nylon fabric was treated as described above in Example 2. Further testing included use of vegetable oil, instead of water as in Example 2, to test the oil-repellency of the various textiles.

Oil droplets formed on untreated nylon fabric but started to spread immediately (Figure 11A). When nylon fabric was treated with both octanoic acid and octadecylamine, an oil droplet formed on the treated nylon fabric and did not spread after 1 minute (Figure 1 IB). Oil droplets spread and penetrated through untreated nylon fabric after 2.5 hours (Figure 12A). However, when nylon fabric was treated with both octanoic acid and octadecylamine, an oil droplet did not spread or penetrate the treated nylon fabric after 2.5 hours (Figure 12B).

When nylon fabric was treated with both octanoic acid and octadecylamine, the treated fabric resisted penetration of the oil for 2 days of continuous exposure (Figure 13, center droplet) and simultaneously shows water repellency with high contact angle (Figure 13, left and right droplets).

An oil droplet (Figure 14A, center droplet) and water droplets (Figure 14A, left and right droplets) were also formed on untreated nylon fabric. After 1 hour, untreated nylon fabric could not could not resist the spreading and penetration of the oil and impacted the water repellency (Figure 14B).

Example 4: Functionalization of Synthetic Textile Fibers During Production

Materials

Nylon 6

Process

A schematic of a synthetic fiber production setup that can be used to make an exemplary synthetic textile described here is shown in Figure 15. The feedstock for nylon, propylene or polyester fiber manufacturing can be either chips or the polymers can be produced continuously. In Figure 15, the hopper (1) contains the chips (2) and feeds the chips into the extruder (3) that is able to heat, melt, and mix the polymer. Extruders can have multiple headed zones. Figure 15 depicts a 3 zone extruder with heated zones (4), (5), and (6) that correspond to heated zones 1, 2, and 3, respectively. The anionic or cationic surfactant can be fed into the extruder through input port (7) or can be added to the hopper (1) or premixed with the chips (2). Some surfactants may have to be melted prior to addition. The heated, melted mixed material (8) can be mixed by the screw (9). A single screw is illustrated but an extruder can have more than one screw. The screw (9) also advances the material to the melt pump (10). The pumped polymer can then be fed to the fiber spinner (11) that is set to a desired temperature. This spinner can spin the fiber (12) that is cooled in the quenching chamber (13) using air (14) whose flow rate and temperature are also set. Any fiber finishing can be applied (15) before the fiber is wound (16). Once the polymer is melted and the surfactant mixed, the anionic or cationic hydrophilic region of the surfactant will move to the surface of the fiber while the fiber is being formed. The oppositely charged surfactant or other oppositely charged molecule can be added as a special finishing step (15) where the fiber would be exposed to a solution containing the surfactant then washed and dried before being wound. This could be used produce a functionalized synthetic fiber or textile as illustrated in Figures 16A, 16B, 18A, or 18B.

The following is a process for creating a functionalized nylon 6 fiber. Octanoic acid surfactant can be premixed with chips of nylon 6 at a concentration of 1% to 10% w/w surfactant to nylon 6. The extruder can be operated in a manner consistent with standard extrusion processes used to produce nylon 6 fibers. A typical 3 zone extruder can be used where the screw and barrel design are as follows. Barrels can have a L/D (length/diameter) ratio of at least 20/1. Screws can be designed with three zones (feed, compression, and metering) with a square pitch. For a typical 24-D screw, the feed zone can be 10-D, the compression zone can be 6-D, and the metering zone can be 8-D. For diameters of 2.5”, 3.5” and 4.5”, the (feed channel depth, metering zone depth, and compression ratio) would be (0.42”, 0.11” and 3.8”), (0.51”, 0.13” and 3.9”), and (0.56”. 0.14” and 4.0”), respectively. Extruder zones 1, 2, and 3 can be set to a temperature of 210-230 degrees C, 230-250 degrees C, and 240-260 degrees C, respectively. Zone 3 temperature may be as high as 300 degrees C. The spinner temperature can be 240-300 degrees C. Fibers may be quenched with an air temperature of 20-120 degrees C. Larger fibers may require liquid quenching from 20-90 degrees C. The oppositely charge surfactant can then applied at the finishing step. 1- octadecylamine hydrochloride (3 g octadecyl-amine in 100 mL ethanol) can be applied to the fiber. Or the fiber can be processed into textiles, and the textiles can be soaked in 1- octadecylamine hydrochloride (3 g octadecyl-amine in 100 mL ethanol) for 5-30 minutes then dried at 120 degrees C for 2 minutes.

In some cases, the electrostatic bonds are converted into covalent bonds as described elsewhere (see, e.g., Kast et al., Biomaterials, 22:2345-2352 (2001); and Kast et. al., Int. J. Pharmaceut., 256: 183-189 (2003)).

OTHER EMBODIMENTS

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A textile comprising cellulose fibers, wherein said cellulose fibers comprise a surface modification comprising surface hydroxyl groups converted to anionic acid groups and further comprising a cationic surfactant attached to said anionic acid groups to modify the surface, and wherein said textile is more water-repellent than a comparable textile lacking said surface modification.

2. The textile of claim 1, wherein said textile comprising said cellulose fibers is selected from the group consisting of cotton, bamboo, coir, flax, hemp, jute, rayon, nylon, and a combination of any of these.

3. The textile of any one of claims 1-2, wherein said textile comprising said cellulose fibers comprises at least 10% cellulose fibers.

4. The textile of any one of claims 1-3, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethyl ammonium chloride or another salt thereof, trimethyl stearylammonium chloride or another salt thereof, and cetrimide.

5. The textile of any one of claims 1-4, wherein said cationic surfactant is attached to said anionic acid groups via an electrostatic bond, an ionic bond, or a covalent bond.

6. A method for modifying a textile comprising cellulose fibers to increase its hydrophobicity, wherein said method comprises:

(a) contacting said textile comprising said cellulose fibers with a solution comprising an acid to convert surface hydroxyl groups present in said cellulose fibers to anionic acid groups; and

(b) contacting said textile comprising said cellulose fibers comprising said anionic acid groups with a solution comprising a cationic surfactant; wherein a positively charged functional group present in a hydrophilic region of said cationic surfactant attaches to said anionic acid groups, thereby making at least the surface of said textile more hydrophobic.

7. The method of claim 6, wherein said textile comprising said cellulose fibers is selected from the group consisting of cotton, bamboo, coir, flax, hemp, jute, rayon, nylon, and a combination of any of these.

8. The method of any one of claims 6-7, wherein said textile comprising said cellulose fibers comprises at least 10% cellulose fibers.

9. The method of any one of claims 6-8, wherein said acid is selected from the group consisting of chloroacetic acid, phthalic acid, succinic acid, and maleic acid.

10. The method of claim 9, wherein said solution comprising said acid is an aqueous solution.

11. The method of any one of claims 6-10, wherein contacting said textile comprising said cellulose fibers with said solution comprising said acid is effective to convert from about 0.1% to about 35% of said surface hydroxyl groups present in said cellulose fibers to said anionic acid groups.

12. The method of any one of claims 6-8, wherein said cationic surfactant is a non-toxic cationic surfactant selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethylammonium chloride or another salt thereof, trimethylstearylammonium chloride or another salt thereof, and cetrimide.

13. The method of claim 12, wherein said solution comprising said cationic surfactant is an aqueous solution.

14. The method of any one of claims 6-13, wherein said attachment is an electrostatic bond, an ionic bond, or a covalent bond.

15. A textile comprising cellulose fibers produced by the method of any one of claims 6-14.

16. A textile comprising synthetic fibers, an anionic surfactant, and a coating attached to at least some of said synthetic fibers, wherein said synthetic fibers contains said anionic surfactant such that negatively charged regions of said anionic surfactant are present on a surface of said textile, wherein said coating comprises a non-toxic cationic surfactant attached to said negatively charged regions, and wherein said textile is more water-repellent than a comparable textile lacking said coating.

17. The textile of claim 16, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

18. The textile of any one of claims 16-17, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

19. The textile of any one of claims 16-18, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethyl ammonium chloride or another salt thereof, trimethylstearylammonium chloride or another salt thereof, and cetrimide.

20. The textile of any one of claims 16-19, wherein said non-toxic cationic surfactants are attached to said negatively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

21. A method for modifying a textile comprising synthetic fibers to increase its hydrophobicity, said method comprising:

(a) producing said synthetic fibers in the presence of an anionic surfactant such that negatively charged regions of said anionic surfactant are present on a surface of said textile comprising said synthetic fibers; and

(b) contacting said textile comprising said synthetic fibers comprising said negatively charged acid groups with a solution comprising a cationic surfactant; wherein a positively charged functional group present in a hydrophilic region of said cationic surfactant attaches to said negatively charged regions, thereby making at least the surface of said textile more hydrophobic.

22. The method of claim 21, wherein said producing said synthetic fibers in the presence of said anionic surfactant comprises adding said anionic surfactant to melted synthetic fibers in an extruder.

23. The method of any one of claims 21-22, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

24. The method of any one of claims 21-23, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, sodium dodecyl sulfate or another salt thereof sodium lauroyl sarcosinate or another salt thereof, and sodium oleyl sarcosinate or another salt thereof.

25. The method of any one of claims 21-24, wherein said cationic surfactant is a nontoxic cationic surfactant selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethylammonium chloride or another salt thereof, trimethylstearylammonium chloride or another salt thereof, and cetrimide.

26. The method of claim 25, wherein said solution comprising said cationic surfactant is an aqueous solution.

27. The method of any one of claims 21-26, wherein said cationic surfactant attaches to said negatively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

28. A textile comprising synthetic fibers produced by the method of any one of claims 21 -27.

29. A textile comprising synthetic fibers, an anionic surfactant, and a coating attached to at least some of said synthetic fibers, wherein said synthetic fibers contains said anionic surfactant such that negatively charged regions of said anionic surfactant are present on a surface of said textile, wherein said coating comprises a non-toxic molecule containing a hydrophobic central region and a positively charged cationic region at both ends, wherein at least one end is attached to said negatively charged regions, and wherein said textile is more oil-repellent and water-resistant than a comparable textile lacking said coating.

30. The textile of claim 29, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

31. The textile of any one of claims 29-30, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

32. The textile of any one of claims 29-31, wherein said molecule containing said hydrophobic central region and said positively charged cationic region at both ends is a 1,N - diamine (e.g., a l,N-diamino-Ci-N alkane, wherein N can be from 8-30, such as 1,8- diaminooctane or 1,12-diaminododecane).

33. The textile of any one of claims 29-32, wherein said molecule containing said hydrophobic central region and said positively charged cationic region at both ends are attached to said negatively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

34. A method for modifying a textile comprising synthetic fibers to increase its oil repellency and water resistance, said method comprising:

(b) contacting said textile comprising said synthetic fibers comprising said negatively charged acid groups with a solution comprising a molecule containing a hydrophobic central region and a positively charged cationic region at both ends; wherein a positively charged functional group present in a hydrophilic region of said molecule containing a hydrophobic central region and a positively charged cationic region at both ends attaches to said negatively charged regions, thereby making at least the surface of said textile to be more oil repellant and more water resistant.

35. The method of claim 34, wherein said producing said synthetic fibers in the presence of said anionic surfactant comprises adding said anionic surfactant to melted synthetic fibers in an extruder.

36. The method of any one of claims 34-35, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

37. The method of any one of claims 34-36, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

38. The method of any one of claims 34-37, wherein said molecule containing said hydrophobic central region and said positively charged cationic region at both ends is a 1,N - diamine (e.g., a l,N-diamino-Ci-N alkane, wherein N can be from 8-30, such as 1,8- diaminooctane or 1,12-diaminododecane).

39. The method of claim 38, wherein said solution comprising said molecule is an aqueous solution.

40. The method of any one of claims 34-39, wherein said molecule attaches to said negatively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

41. A textile comprising synthetic fibers produced by the method of any one of claims 34-40.

42. A textile comprising synthetic fibers, a cationic surfactant, and a coating attached to at least some of said synthetic fibers, wherein said synthetic fibers contains said cationic surfactant such that positively charged regions of said cationic surfactant are present on a surface of said textile, wherein said coating comprises a non-toxic anionic surfactant attached to said positively charged regions, and wherein said textile is more water-repellent than a comparable textile lacking said coating.

43. The textile of claim 42, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

44. The textile of any one of claims 42-43, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethyl ammonium chloride or another salt thereof, trimethyl stearylammonium chloride or another salt thereof, and cetrimide.

45. The textile of any one of claims 42-44, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

46. The textile of any one of claims 42-45, wherein said non-toxic anionic surfactants are attached to said positively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

47. A method for modifying a textile comprising synthetic fibers to increase its hydrophobicity, said method comprising:

(a) producing said synthetic fibers in the presence of a cationic surfactant such that positively charged regions of said cationic surfactant are present on a surface of said textile comprising said synthetic fibers; and

(b) contacting said textile comprising said synthetic fibers comprising said positively charged acid groups with a solution comprising an anionic surfactant; wherein a negatively charged functional group present in a hydrophilic region of said anionic surfactant attaches to said positively charged regions, thereby making at least the surface of said textile more hydrophobic.

48. The method of claim 47, wherein said producing said synthetic fibers in the presence of said cationic surfactant comprises adding said cationic surfactant to melted synthetic fibers in an extruder.

49. The method of any one of claims 47-48, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

50. The method of any one of claims 47-49, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethyl ammonium chloride or another salt thereof, trimethyl stearylammonium chloride or another salt thereof, and cetrimide.

51. The method of any one of claims 47-50, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

52. The method of claim 47, wherein said solution comprising said anionic surfactant is an aqueous solution.

53. The method of any one of claims 47-52, wherein said anionic surfactant attaches to said positively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

54. A textile comprising synthetic fibers produced by the method of any one of claims 47-53.

55. A textile comprising synthetic fibers, a cationic surfactant, and a coating attached to at least some of said synthetic fibers, wherein said synthetic fibers contains said cationic surfactant such that positively charged regions of said cationic surfactant are present on a surface of said textile, wherein said coating comprises a non-toxic molecule containing a hydrophobic central region and a negatively charged anionic region at both ends, wherein at least one end is attached to said positively charged regions, and wherein said textile is more oil-repellent and water-resistant than a comparable textile lacking said coating.

56. The textile of claim 55, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

57. The textile of any one of claims 55-56, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethyl ammonium chloride or another salt thereof, trimethyl stearylammonium chloride or another salt thereof, and cetrimide.

58. The textile of any one of claims 55-57, wherein said molecule containing said hydrophobic central region and said negatively charged anionic region at both ends is a 1,N - alkanedioic acid (e.g., a 1,N-CI-N alkanedioic acid, wherein N can be from 8-30, such as 1,8- octanedioic acid or 1,12-dodecanedioic acid).

59. The textile of any one of claims 55-58, wherein said molecule containing said hydrophobic central region and said negatively charged anionic region at both ends are attached to said negatively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

60. A method for modifying a textile comprising synthetic fibers to increase its oil repellency and water resistance, said method comprising:

(b) contacting said textile comprising said synthetic fibers comprising said positively charged acid groups with a solution comprising a molecule containing a hydrophobic central region and a negatively charged anionic region at both ends; wherein a negatively charged functional group present in a hydrophilic region of said molecule containing a hydrophobic central region and a negatively charged anionic region at both ends attaches to said positively charged regions, thereby making at least the surface of said textile to be more oil repellant and more water resistant.

61. The method of claim 60, wherein said producing said synthetic fibers in the presence of said cationic surfactant comprises adding said cationic surfactant to melted synthetic fibers in an extruder.

62. The method of any one of claims 60-61, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

63. The method of any one of claims 60-62, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N- hexadecyltrimethylammonium chloride or another salt thereof, trimethylstearylammonium chloride or another salt thereof, and cetrimide.

64. The method of any one of claims 60-63, wherein said molecule containing said hydrophobic central region and said negatively charged anionic region at both ends is a 1,N - alkanedioic acid (e.g., a 1,N-CI-N alkanedioic acid, wherein N can be from 8-30, such as 1,8- octanedioic acid or 1,12-dodecanedioic acid)..

65. The method of claim 60, wherein said solution comprising said molecule is an aqueous solution.

66. The method of any one of claims 60-65, wherein said molecule attaches to said positively charged regions via an electrostatic bond, an ionic bond, or a covalent bond.

67. A textile comprising synthetic fibers produced by the method of any one of claims 60-66.

68. A textile comprising synthetic fibers and a charged surfactant, wherein said synthetic fibers contains said charged surfactant such that charged regions of said charged surfactant are present on a surface of said textile and such that hydrophobic regions of said charged surfactant have diffused into the surface of said textile.

69. The textile of claim 68, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

70. The textile of any one of claims 68-69, wherein said charged surfactant comprises an anionic surfactant, and wherein said charged regions comprise negatively charged regions.

71. The textile of claim 70, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

72. The textile of any one of claims 68-69, wherein said charged surfactant comprises a cationic surfactant, and wherein said charged regions comprise positively charged regions.

73. The textile of claim 72, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethylammonium chloride or another salt thereof, N-hexadecyltrimethylammonium chloride or another salt thereof, trimethylstearylammonium chloride or another salt thereof, and cetrimide.

74. A method for modifying a textile comprising synthetic fibers to provide one or more charged moieties, said method comprising:

(a) contacting said textile comprising said synthetic fibers with a solution comprising a charged surfactant;

(b) thermally treating said textile to allow diffusion of the charged surfactant into a surface of said textile; and

(c) cooling said textile, wherein charged regions of said charged surfactant are present on said surface of said textile and hydrophobic regions of said charged surfactant have diffused into the surface of said textile.

75. The method of claim 74, wherein said textile comprising said synthetic fibers is selected from the group consisting of nylon, viscose, lyocell, modal, polyester, polypropylene, kevlar, microfiber, modacrylic, spandex, and a combination of any of these.

76. The method of any one of claims 74-75, wherein said charged surfactant comprises an anionic surfactant, and wherein said charged regions comprise negatively charged regions.

77. The method of claim 76, wherein said anionic surfactant is selected from the group consisting of a saturated fatty acid, an unsaturated fatty acid, octanoic acid (also referred to as caprylic acid), stearic acid or a salt thereof (e.g., sodium stearate or another salt thereof), sodium octyl sulfate or another salt thereof, and sodium dodecyl sulfate or another salt thereof.

78. The method of any one of claims 74-75, wherein said charged surfactant comprises a cationic surfactant, and wherein said charged regions comprise positively charged regions.

79. The method of claim 78, wherein said cationic surfactant is selected from the group consisting of a fatty amine, lauric arginate, octadecylamine, nonylamine, dodecyltrimethyl ammonium chloride or another salt thereof, N-hexadecyltrimethylammonium chloride or another salt thereof, trimethyl stearylammonium chloride or another salt thereof, and cetrimide.

80. The method of claim 74, wherein said solution comprising said charged surfactant is an aqueous solution.

81. The method of claim 74, wherein said thermally treating comprises providing an elevated temperature from about 120 degrees C to about 180 degrees C.

82. The method of claim 74, wherein said cooling provides said textile at an ambient temperature (e.g., by way of air drying or forced air drying).

83. The method of any one of claims 74-82, further comprising (e.g., prior to said thermally treating): removing excess of said solution from said textile.

84. The method of any one of claims 74-83, further comprising (e.g., after said thermally treating): washing said textile with a solvent (e.g., water, alcohol, and the like) and drying said textile.

85. A textile comprising synthetic fibers produced by the method of any one of claims 74-84.