CN106930007A - Micro nanometer fiber composite membrane with the unidirectional conducting power of moisture and preparation method thereof - Google Patents

Abstract

The invention discloses a method for preparing a micro-nano fiber composite membrane with moisture unidirectional conductivity, which is characterized in that dopamine hydrochloride is dissolved in a tris-hydroxymethylaminomethane buffer solution to prepare a dopamine solution; the non-woven fabric is immersed in In the above dopamine solution, immerse it at room temperature to form a polydopamine film on the surface of the fiber to obtain a polydopamine pretreated nonwoven fabric; dissolve the hydrophilic nanomaterial in the solvent, and ultrasonically disperse the nanomaterial evenly, and the hydrophilic A type polymer is dissolved in the homogeneous solution obtained above, and a hydrophilic fiber layer is prepared on the polydopamine pretreated nonwoven fabric by an electrospinning method, so as to obtain the micro-nano fiber composite membrane with moisture unidirectional conductivity. The micro-nanofiber composite film prepared by the invention has high-efficiency one-way water conduction ability, that is, has one-way conduction ability for liquid water and gaseous water simultaneously, achieves the effect of moisture conduction and quick drying, and can be used in the fields of clothing, medical care and the like.

Description

Micro-nano fiber composite membrane with moisture unidirectional conductivity and preparation method thereof

technical field

The invention belongs to the technical field of functional micro-nano composite fiber materials, and in particular relates to a non-woven fabric and an electrospun fiber composite film with moisture unidirectional conductivity and a preparation method thereof. One-way conduction between water and gaseous water.

Background technique

Wettability is one of the important properties of solid surfaces, which is determined by the surface chemical composition and surface roughness. Materials with wettability gradients can be obtained by using chemical gradient modification or constructing surface structure gradients, from hydrophobic regions to The hydrophilic area generates an additional pressure difference, and water droplets are transferred from the hydrophobic surface of the material to the hydrophilic surface, thereby realizing the directional drive of the liquid. Usually, this material can be used as a clothing fabric with a hydrophobic inner layer and a hydrophilic outer layer. Sweat is transferred to the outer layer of the fabric under the action of the wetting gradient effect or differential capillary effect and evaporates quickly, so as to achieve the effect of moisture absorption and quick drying. At present, a lot of research has been done at home and abroad on the preparation and application of unidirectional water-conducting functional micro-nano composite fiber materials. The related patented technologies include: a preparation of superhydrophobic and superhydrophilic electrospun nanofiber composite membranes Method (CN102605554A), a composite fiber membrane with unidirectional water permeability and its preparation method (CN102691175A), a spunlace nonwoven material with unidirectional water guide function and its preparation method and application (CN103938368A), a Composite membranes that regulate the one-way permeation range of liquids and their preparation methods (CN105664730A), etc. The research direction is mainly focused on the one-way water-conducting performance, and the preparation and research of micro-nano fiber composite membranes with one-way moisture-conducting function are relatively few , and designing a multifunctional and practical moisture one-way conductive composite material is of great significance for the theoretical research and practical application of one-way moisture conductivity.

Electrospinning technology is a method that can directly and continuously prepare polymer nanofibers. Combined with hydrophilic modification or material doping, the hydrophilicity and hydrophobicity and microstructure of fibers can be effectively adjusted to obtain materials with superhydrophilic properties. Compared with traditional moisture-absorbing and quick-drying fabrics, the electrospun nanofiber membrane has a large specific surface area and strong wicking effect. The prepared micro-nanofiber composite membrane has excellent unidirectional water-conducting, moisture-conducting and quick-drying performance.

Contents of the invention

The problem to be solved by the present invention is to provide a method for preparing a micro-nano fiber composite membrane with one-way conductivity of moisture. The composite membrane prepared by this method has the one-way conductivity of liquid water and gaseous water at the same time.

In order to solve the above problems, the present invention provides a method for preparing a micro-nano fiber composite membrane with moisture unidirectional conductivity, which is characterized in that it comprises the following steps:

The first step: choose an untreated nonwoven fabric;

The second step: prepare a Tris-HCl buffer solution with Tris and hydrochloric acid, and dissolve dopamine hydrochloride in the Tris buffer solution to prepare a dopamine solution;

The third step: immerse the nonwoven fabric in the dopamine solution prepared in the second step, and immerse it at room temperature to form a polydopamine film on the surface of the fiber to obtain a polydopamine pretreated nonwoven fabric;

Step 4: Dissolve the hydrophilic nanomaterials in the solvent, ultrasonically disperse the nanomaterials evenly, dissolve the hydrophilic polymer in the solvent to obtain a spinning solution, and pretreat the nonwovens with polydopamine by electrospinning A layer of hydrophilic nanofiber membrane is deposited on the cloth, so as to obtain the micro-nanofiber composite membrane with moisture one-way conductivity.

Preferably, the nonwoven fabric in the first step is polyester spunbonded nonwoven fabric, polypropylene spunbonded nonwoven fabric, polyethylene spunbonded nonwoven fabric, polyester meltblown nonwoven fabric, Any one or more of polypropylene melt-blown nonwovens and polyethylene melt-blown nonwovens.

Preferably, the fiber diameter of the nonwoven material in the first step is 5-20 μm, and the thickness is 50-200 μm.

Preferably, the concentration of the Tris-HCl buffer solution in the second step is 0.005-0.05 mol/L, and the pH value is 7-9.

Preferably, the concentration of the dopamine solution in the second step is 0.2-2 g/L.

Preferably, the soaking time in the third step is 15-120 minutes.

Preferably, the hydrophilic nanomaterial in the fourth step is any one or several of carbon nanotubes, silica nanoparticles, nano calcium carbonate, metals and metal oxide nanoparticles.

More preferably, the metal nanoparticles are nano-silver; the metal oxide nanoparticles are any one or more of titanium dioxide nanoparticles, zinc oxide nanoparticles and zirconium oxide nanoparticles.

Preferably, the mass fraction of hydrophilic nanoparticles in the spinning solution in the fourth step is 0%-5%.

Preferably, the hydrophilic polymer in the fourth step is a water-soluble polymer or a water-insoluble polymer; the water-soluble polymer is any one of polyvinyl alcohol, sodium polyacrylate and polyacrylamide or several, when preparing this type of polymer electrospinning solution, a crosslinking agent must be added to the solution; non-water-soluble polymers are cellulose acetate, chitosan, polyacrylonitrile, ethylene/vinyl alcohol copolymer, poly Any one or more of amides and polyimides.

More preferably, when the water-soluble polymer in the fourth step is polyvinyl alcohol, the crosslinking agent is any one or more of glutaraldehyde, maleic anhydride and triethylene glycol; When the water-soluble polymer in the fourth step is sodium polyacrylate, the crosslinking agent is any one of hydroxyethyl methacrylate, N, N-methylenebisacrylamide and polyethylene glycol diacrylate one or more; when the water-soluble polymer in the fourth step is polyacrylamide, the crosslinking agent is any one of glutaraldehyde, N, N-methylenebisacrylamide and polyethylene glycol diacrylate species or several.

Preferably, the solvent in the fourth step is deionized water, acetone, acetic acid, N,N-dimethylformamide, N,N-dimethylacetamide, isopropanol, tetrahydrofuran, formic acid, ethylene glycol Any one or more of alcohol, glycerin, methylene chloride, carbon tetrachloride and dimethyl sulfoxide.

Preferably, the mass concentration of the hydrophilic polymer in the spinning solution in the fourth step is 5-30%.

Preferably, the electrospinning voltage in the fourth step is 10-50kV, the receiving distance is 10-30cm, the perfusion speed of the spinning solution is 0.2-5mL/h, and the obtained fiber diameter is 50nm-2μm, and the fiber membrane The thickness is 10-150 μm.

The present invention also provides a micro-nano fiber composite membrane with moisture one-way conductivity prepared by the method for preparing the micro-nano fiber composite membrane with moisture one-way conductivity.

Preferably, the composite membrane can conduct liquid water or/and gaseous water in one direction.

The micro-nano fiber composite membrane prepared by the invention includes a hydrophilic layer and a hydrophobic layer, the hydrophilic layer is an electrospun nanofiber membrane, and the hydrophobic layer is a dopamine-modified non-woven fabric. The wetting gradient difference of the composite membrane in the direction perpendicular to the membrane plane can be changed by changing the pH value of the Tris-HCl buffer solution in the second step, the concentration of dopamine hydrochloride, the treatment time in the third step, and the hydrophilicity in the fourth step. The proportion of hydrophilic nanoparticles doped in the permanent polymer can be adjusted, so that excellent one-way water conductivity can be obtained.

The moisture permeability of the micro-nanofiber composite film prepared by the present invention is ≥10000g/m2/d along the surface of the electrospun nanofiber membrane of the nonwoven fabric, the one-way transmission index is ≥1000, and the dynamic transmission index of liquid water is ≥0.95. The moisture permeability of the spun nanofiber membrane facing the non-woven fabric surface is ≤4000g/m2/d, the one-way transmission index is ≤-500, and the comprehensive index of liquid water dynamic transmission is ≤0.4.

Compared with prior art, the beneficial effect of the present invention is:

(1) The dopamine-modified nonwoven layer and the electrospun nanofiber film layer in the composite film of the present invention are prepared by in-situ polymerization and electrospinning processes, respectively. The method is simple, combining hydrophilic modification and nanomaterial doping can effectively regulate the hydrophilicity and hydrophobicity and microstructure of the fiber, and obtain materials with superhydrophilic properties;

(2) In the composite film of the present invention, the hydrophobic layer is made up of hydrophobic non-woven fabrics. The selected non-woven material itself is hydrophobic, and the fiber hygroscopicity is poor. On this basis, dopamine is modified to form a layer of hydrophilic material on the surface of the fiber. For the water-based polydopamine film, the chemical properties inside the fiber have not changed, and it still maintains a certain degree of hydrophobicity. Therefore, under the action of the capillary effect, the water conductivity of the hydrophobic layer material has been enhanced, while the hygroscopicity has not changed. ;

(3) In the composite membrane of the present invention, the hydrophilic layer is composed of a hydrophilic nanofiber membrane, and the hydrophilicity of the fiber membrane is further improved by doping with a hydrophilic nanomaterial, and the fiber membrane is endowed with a micro/nanostructure double-dimensional roughness , thus achieving superhydrophilicity. Compared with traditional fibers, electrospun fibers have a smaller diameter and larger specific surface area. When water is transferred from the hydrophobic surface to the hydrophilic surface, it can evaporate quickly, thereby achieving excellent unidirectional water conduction, moisture conduction and quick-drying performance.

Description of drawings

FIG. 1 is an electron micrograph of the micro-nanofiber composite film prepared in Example 1.

detailed description

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with accompanying drawings.

The weight-average molecular weight of polyvinyl alcohol used in Examples 1-8 is 11-13W, the weight-average molecular weight of sodium polyacrylate is 5000, the weight-average molecular weight of polyacrylamide is 100W, the weight-average molecular weight of cellulose acetate is 10W, The weight average molecular weight of chitosan is 30W, the weight average molecular weight of polyacrylonitrile is 10W, the weight average molecular weight of ethylene/vinyl alcohol copolymer is 5W, the weight average molecular weight of polyamide is 3W and the weight average molecular weight of polyimide It is 5W. Solvent Deionized water, acetone, acetic acid, N,N-dimethylformamide, N,N-dimethylacetamide, isopropanol, tetrahydrofuran, formic acid, ethylene glycol, glycerol, dichloromethane, tetrahydrofuran Both carbon chloride and dimethyl sulfoxide were produced by Shanghai Jingchun Reagent Co., Ltd. The high-voltage power supply is DW-P303-1ACD8 produced by Tianjin Dongwen High-voltage Power Supply Factory.

Example 1

As shown in Figure 1, a micro-nano fiber composite membrane with moisture unidirectional conductivity is composed of a superhydrophilic layer (a) and a hydrophobic layer (b), and its preparation method is:

Step 1: Provide a polypropylene spunbonded nonwoven fabric with a fiber diameter of 10 μm and a thickness of 100 μm;

The second step: prepare a 0.005 mol/L tris hydrochloride (Tris-HCl) buffer solution with a pH value of 7 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 1g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse the polypropylene spunbonded nonwoven fabric in the above dopamine solution, immerse at room temperature for 1 hour to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to prepare the polydopamine pretreated nonwoven fabric. woven cloth;

Step 4: Dissolve the hydrophilic silicon dioxide nanoparticles in water, and ultrasonically disperse the nanoparticles uniformly to obtain a silicon dioxide solution with a mass fraction of 2%; dissolve polyvinyl alcohol in the above prepared solution to prepare a mass A polyvinyl alcohol electrospinning solution with a fraction of 15%, and glutaraldehyde was added as a crosslinking agent. A layer of hydrophilic nanofiber film was deposited on the dopamine pretreated nonwoven fabric, the spinning voltage was 40kV, the receiving distance was 20cm, the infusion rate of the spinning solution was 2mL/h, the obtained fiber diameter was 300nm, and the fiber film thickness was 30μm. In order to obtain the micro-nano fiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1050, and the liquid water The dynamic transmission comprehensive index is 0.96; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 11200g/m2/d; The moisture permeability facing the nonwoven fabric surface is 4700g/m2/d, the one-way transmission index is -470, and the comprehensive index of liquid water dynamic transmission is 0.35.

Example 2

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

Step 1: Provide a polyester spunbonded nonwoven fabric with a fiber diameter of 7 μm and a thickness of 80 μm;

The second step: prepare a 0.01mol/L Tris-HCl buffer solution with a pH value of 8 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 2g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse the polyester spunbonded nonwoven fabric in the above-mentioned dopamine solution, immerse at room temperature for 0.5h to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to obtain the polydopamine pretreatment Non-woven;

The fourth step: dissolve the hydrophilic titanium dioxide nanoparticles in water, and ultrasonically disperse the nanoparticles uniformly to prepare a titanium dioxide solution with a mass fraction of 1%; dissolve sodium polyacrylate in the above-mentioned solution to prepare a mass fraction of 20% Sodium polyacrylate electrospinning solution, and adding hydroxyethyl methacrylate as a crosslinking agent, hydroxyethyl methacrylate accounted for 5% of the mass fraction of sodium polyacrylate, stirred evenly to obtain a spinning solution, through the electrospinning method Deposit a layer of hydrophilic nanofiber film on the polydopamine pretreated nonwoven fabric, the spinning voltage is 30kV, the receiving distance is 20cm, the perfusion speed of the spinning solution is 1mL/h, the obtained fiber diameter is 200nm, and the fiber film thickness is 40 μm. In order to obtain the micro-nanofiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1120, and the liquid water The dynamic transmission comprehensive index is 0.97; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 12100g/m2/d; The moisture permeability facing the non-woven fabric surface is 3700g/m2/d, the one-way transmission index is -380, and the comprehensive index of liquid water dynamic transmission is 0.32.

Example 3

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

The first step: providing a polyethylene spunbonded nonwoven fabric with a fiber diameter of 5 μm and a thickness of 80 μm;

The second step: prepare a 0.02 mol/L Tris-HCl buffer solution with a pH value of 8.5 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 1g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse polyethylene spunbonded nonwoven fabric in the above-mentioned dopamine solution, soak for 2 hours at room temperature to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to obtain a polydopamine pretreated nonwoven fabric. woven cloth;

Step 4: Dissolve hydrophilic carbon nanotubes in acetone, ultrasonically disperse the nanomaterials evenly, and prepare a carbon nanotube solution with a mass fraction of 4%; dissolve cellulose acetate in the above-mentioned solution to prepare mass The cellulose acetate electrospinning solution with a fraction of 30% was stirred evenly to obtain a spinning solution, and a layer of hydrophilic nanofiber film was deposited on the polydopamine pretreated nonwoven fabric by electrospinning, and the spinning voltage was 50kV, and the receiving The distance is 25 cm, the perfusion rate of the spinning solution is 2 mL/h, the diameter of the obtained fiber is 300 nm, and the thickness of the fiber film is 80 μm. In order to obtain the micro-nanofiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1310, and the liquid water The comprehensive index of dynamic transfer is 0.99; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 14300g/m2/d; The moisture permeability facing the nonwoven fabric surface is 3200g/m2/d, the one-way transmission index is -650, and the comprehensive index of liquid water dynamic transmission is 0.34.

Example 4

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

The first step: provide a polyester spunbonded nonwoven fabric with a fiber diameter of 8 μm and a thickness of 100 μm;

The second step: prepare a 0.03 mol/L Tris-HCl buffer solution with a pH value of 8.5 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 1.5g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse the polyester spunbonded nonwoven fabric in the above-mentioned dopamine solution, soak for 1.5 hours at room temperature to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to obtain the polydopamine pretreatment Non-woven;

The 4th step: be dissolved in the acetic acid of hydrophilic nano-calcium carbonate, ultrasound makes nano-particle disperse evenly, make the calcium carbonate solution that mass fraction is 3%; Dissolve chitosan in the above-mentioned prepared solution and prepare mass fraction as 20% chitosan electrospinning solution, deposit a layer of hydrophilic nanofiber film on polydopamine pretreated nonwovens by electrospinning method, the spinning voltage is 30kV, the receiving distance is 25cm, the perfusion speed of spinning solution 2mL/h, the obtained fiber diameter is 350nm, and the fiber film thickness is 50μm. In order to obtain the micro-nanofiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1120, and the liquid water The dynamic transmission comprehensive index is 0.98; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 12700g/m2/d; The moisture permeability facing the non-woven fabric surface is 4500g/m2/d, the one-way transmission index is -360, and the dynamic transmission index of liquid water is 0.39.

Example 5

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

The first step: provide a polypropylene melt-blown nonwoven fabric with a fiber diameter of 4 μm and a thickness of 50 μm;

The second step: prepare a 0.02 mol/L Tris-HCl buffer solution with a pH value of 8.5 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 2g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse the polypropylene melt-blown non-woven fabric in the above-mentioned dopamine solution, immerse it at room temperature for 2 hours to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to obtain a polydopamine pretreated non-woven fabric. woven cloth;

The fourth step: dissolve the hydrophilic zinc oxide nanoparticles in water, ultrasonically disperse the nanoparticles evenly, and prepare a zinc oxide solution with a mass fraction of 5%; dissolve polyacrylonitrile in the above-mentioned solution to prepare the mass fraction 18% polyacrylonitrile electrospinning solution, deposited a layer of hydrophilic nanofiber film on polydopamine pretreated nonwovens by electrospinning method, the spinning voltage was 35kV, the receiving distance was 25cm, the perfusion of spinning solution The speed was 1.5 mL/h, the obtained fiber diameter was 350 nm, and the fiber film thickness was 100 μm. In order to obtain the micro-nano fiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1350, and the liquid water The dynamic transmission comprehensive index is 0.99; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 14100g/m2/d, and the moisture permeability along the surface of the electrospun nanofiber membrane The moisture permeability facing the nonwoven fabric surface is 2900g/m2/d, the one-way transmission index is -550, and the comprehensive index of liquid water dynamic transmission is 0.37.

Example 6

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

The first step: provide a polyester melt-blown nonwoven fabric with a fiber diameter of 5 μm and a thickness of 80 μm;

The second step: prepare a 0.05 mol/L Tris-HCl buffer solution with a pH value of 8.5 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 0.5g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse the polyester melt-blown non-woven fabric in the above-mentioned dopamine solution, and immerse it at room temperature for 1 hour to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to obtain a polydopamine pretreated non-woven fabric. woven cloth;

The fourth step: dissolve the hydrophilic zirconia nanoparticles in isopropanol, and ultrasonically disperse the nanoparticles evenly to obtain a zirconia solution with a mass fraction of 5%; dissolve the ethylene/vinyl alcohol copolymer in the above-mentioned Prepare the ethylene/vinyl alcohol copolymer electrospinning solution with a mass fraction of 10% in the preparation solution, deposit a layer of hydrophilic nanofiber film on the polydopamine pretreated nonwoven fabric by electrospinning method, and the spinning voltage is 30kV, The receiving distance was 20 cm, the perfusion rate of the spinning solution was 1 mL/h, the obtained fiber diameter was 300 nm, and the fiber film thickness was 40 μm. In order to obtain the micro-nano fiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1150, and the liquid water The dynamic transmission comprehensive index is 0.96; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 10500g/m2/d, and the moisture permeability along the surface of the electrospun nanofiber membrane The moisture permeability facing the non-woven fabric surface is 3500g/m2/d, the one-way transmission index is -560, and the dynamic transmission index of liquid water is 0.36.

Example 7

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

The first step: provide a polyethylene melt-blown nonwoven fabric with a fiber diameter of 4 μm and a thickness of 70 μm;

The second step: prepare a 0.07 mol/L Tris-HCl buffer solution with a pH value of 7 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 1g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

Step 3: Immerse polyethylene melt-blown nonwovens in the above-mentioned dopamine solution, immerse at room temperature for 1 hour to form a polydopamine film on the surface of the fiber, wash with distilled water and dry at 60°C to obtain polydopamine pretreated non-woven fabrics. woven cloth;

Step 4: Dissolve hydrophilic silicon dioxide nanoparticles in formic acid, and ultrasonically disperse the nanoparticles uniformly to obtain a silicon dioxide solution with a mass fraction of 5%; dissolve polyamide in the above-mentioned solution to prepare A polyamide electrospinning solution with a mass fraction of 15%, deposits a layer of hydrophilic nanofiber film on the polydopamine pretreated nonwoven fabric by electrospinning, the spinning voltage is 30kV, and the receiving distance is 20cm. The perfusion rate was 1 mL/h, the diameter of the obtained fiber was 100 nm, and the thickness of the fiber film was 30 μm. In order to obtain the micro-nanofiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1180, and the liquid water The dynamic transmission comprehensive index is 0.97; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 11200g/m2/d, and the moisture permeability along the surface of the electrospun nanofiber membrane The moisture permeability facing the non-woven fabric surface is 3200g/m2/d, the one-way transmission index is -580, and the dynamic transmission index of liquid water is 0.34.

Example 8

A micro-nano fiber composite membrane with moisture unidirectional conduction capacity, which is composed of a super-hydrophilic layer and a hydrophobic layer, and its preparation method is as follows:

The first step: provide a polypropylene melt-blown nonwoven fabric with a fiber diameter of 5 μm and a thickness of 80 μm;

The second step: prepare a 0.01 mol/L Tris-HCl buffer solution with a pH value of 8.5 with tris and hydrochloric acid, and the pH value of the solution can be adjusted by hydrochloric acid. Weigh 2g of dopamine hydrochloride and dissolve it in 1L of Tris buffer solution to prepare a dopamine solution, which is ready-to-use;

The third step: immerse the polypropylene melt-blown non-woven fabric in the above-mentioned dopamine solution, immerse it at room temperature for 2 hours to form a polydopamine film on the surface of the fiber, wash it with distilled water and dry it at 60°C to obtain a polydopamine pretreated non-woven fabric. woven cloth;

The fourth step: dissolve the hydrophilic titanium dioxide nanoparticles in N-N dimethylformamide, ultrasonically disperse the nanoparticles uniformly, and prepare a titanium dioxide solution with a mass fraction of 5%; dissolve the polyimide in the above prepared Prepare a polyimide electrospinning solution with a mass fraction of 20% in the solution, and deposit a layer of hydrophilic nanofiber film on the polydopamine pretreated nonwoven fabric by electrospinning method, the spinning voltage is 30kV, and the receiving distance is 25cm , the perfusion rate of the spinning solution was 2mL/h, the obtained fiber diameter was 200nm, and the fiber film thickness was 50μm. In order to obtain the micro-nano fiber composite membrane with moisture unidirectional conductivity, according to the national standard GB/T 21655.2-2009, the one-way transmission index of the membrane along the nonwoven fabric facing the electrospun nanofiber membrane surface is 1290, and the liquid water dynamics is 1290. The transfer comprehensive index is 0.99; according to the national standard GB/T12704.2-2009 positive cup method, the moisture permeability of the film along the surface of the nonwoven fabric facing the electrospun nanofiber membrane is 12400g/m2/d, and along the surface of the electrospun nanofiber membrane The moisture permeability of the nonwoven surface is 3600g/m2/d, the one-way transmission index is -620, and the comprehensive index of liquid water dynamic transmission is 0.35.

Claims (16)

1. a kind of preparation method of the micro nanometer fiber composite membrane with the unidirectional conducting power of moisture, it is characterised in that including with Lower step：

The first step：Select a undressed non-weaving cloth；

Second step：Tri(Hydroxymethyl) Amino Methane Hydrochloride cushioning liquid is prepared with trishydroxymethylaminomethane and hydrochloric acid, by hydrochloric acid Dopamine is obtained dopamine solution in being dissolved in trishydroxymethylaminomethane cushioning liquid；

3rd step：Non-weaving cloth is immersed in dopamine solution obtained in second step, dipping makes it in fiber surface shape at room temperature Into poly-dopamine film, poly-dopamine pretreatment non-weaving cloth is obtained；

4th step：Hydrophilic nano material is dissolved in solvent, ultrasound causes that nano material is dispersed, by hydrophilic polymers It is dissolved in solvent, obtains spinning solution, is pre-processed in poly-dopamine by electrospinning process and one layer of parent is deposited on non-weaving cloth Water type nano fibrous membrane, so as to obtain the micro nanometer fiber composite membrane with the unidirectional conducting power of moisture.

2. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the non-weaving cloth in the first step is spunbond polyester method non-weaving cloth, PP cellular, polyethylene Spunbonded Nonwovens, polyester meltblown method non-weaving cloth, polypropylene melt spray non-weaving cloth and polyethylene meltblown method non-weaving cloth In any one or a few.

3. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 1 or 2, its It is characterised by, the non-woven material fibre diameter in the first step is 5~20 μm, thickness is 50~200 μm.

4. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the concentration of the Tri(Hydroxymethyl) Amino Methane Hydrochloride cushioning liquid in the second step is 0.005~0.05mol/L, PH value is 7~9.

5. the preparation method of the micro nanometer fiber composite membrane with the unidirectional conducting power of moisture as described in claim 1 or 4, its It is characterised by, the dopamine solution concentration in the second step is 0.2~2g/L.

6. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the dip time in the 3rd step is 15~120min.

7. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the hydrophilic nano material in the 4th step is CNT, nano SiO 2 particle, nano-calcium carbonate, gold Category and metal oxide nanoparticles in any one or a few.

8. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 7, it is special Levy and be, the metal nanoparticle is Nano Silver；The metal oxide nanoparticles are titania nanoparticles, oxidation Any one or a few in zinc nanoparticles and Zirconium oxide nano grain.

9. the preparation method of the micro nanometer fiber composite membrane with the unidirectional conducting power of moisture as described in claim 1 or 7, its It is characterised by, the mass fraction of hydrophilic nano particle is 0%~5% in the spinning solution in the 4th step.

10. there is the preparation method of the micro nanometer fiber composite membrane of the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the hydrophilic polymers in the 4th step are water-soluble polymer or non-soluble polymer；The water-soluble poly Compound be polyvinyl alcohol, Sodium Polyacrylate and polyacrylamide in any one or a few, preparing such polymer electrospinning During solution, must be to adding crosslinking agent in solution；Non-soluble polymer be cellulose acetate, shitosan, polyacrylonitrile, ethene/ Any one or a few in ethenol copolymer, polyamide and polyimides.

The preparation method of the 11. micro nanometer fiber composite membranes with the unidirectional conducting power of moisture as claimed in claim 10, its Be characterised by, the water-soluble polymer in the 4th step be polyvinyl alcohol when, crosslinking agent be glutaraldehyde, maleic anhydride and Any one or a few in triethylene-glycol；When water-soluble polymer in 4th step is Sodium Polyacrylate, crosslinking Agent be hydroxyethyl methacrylate, N, in N- methylene-bisacrylamides and polyethyleneglycol diacrylate any one or it is several Kind；When water-soluble polymer in 4th step is polyacrylamide, crosslinking agent is glutaraldehyde, N, N- methylene bisacrylamide acyls Any one or a few in amine and PVOH diacrylate.

The preparation method of the 12. micro nanometer fiber composite membranes with the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the solvent in the 4th step is deionized water, acetone, acetic acid, DMF, N, N- dimethylacetamides It is any one in amine, isopropanol, tetrahydrofuran, formic acid, ethylene glycol, glycerine, dichloromethane, carbon tetrachloride and dimethyl sulfoxide (DMSO) Plant or several.

The preparation method of the 13. micro nanometer fiber composite membranes with the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the mass concentration of hydrophilic polymers is 5~30% in the spinning solution in the 4th step.

The preparation method of the 14. micro nanometer fiber composite membranes with the unidirectional conducting power of moisture as claimed in claim 1, it is special Levy and be, the voltage of the electrostatic spinning in the 4th step is 10~50kV, it is 10~30cm, the filling of spinning solution to receive distance Note speed is 0.2~5mL/h, and gained fibre diameter is 50nm~2 μm, and fiber film thickness is 10~150 μm.

The micro nanometer fiber with the unidirectional conducting power of moisture described in a kind of 15. use claim 1-14 any one is combined The obtained micro nanometer fiber composite membrane with the unidirectional conducting power of moisture of the preparation method of film.

The 16. micro nanometer fiber composite membranes with the unidirectional conducting power of moisture as claimed in claim 15, it is characterised in that institute Stating composite membrane can unidirectionally conduct aqueous water or/and vaporous water.