PL226095B1 - Process for producing cellulose and a photo-stable composite oxide of titanium (IV) using the cyclo-hexyl-ammonium ionic liquids - Google Patents

Description

Description of the invention

The subject of the invention is a new method for the production of photostable composites of cellulose and titanium (IV) oxide using cyclohexylammonium ionic liquids used as additives for the production of materials with improved ability to absorb ultraviolet radiation.

Cellulose as the main component of plant cells is the most abundant natural polymer on Earth. Using it as an energy source or converting it to chemicals is the subject of research of many research centers. Due to the numerous hydrogen bonds between polyglycoside chains, cellulose is insoluble in water and common organic solvents. The first attempts to dissolve cellulose or materials containing a large amount of it took place as early as the 19th century. Since then, many solvents that have the ability to dissolve cellulose have been discovered, but all of them are highly toxic, disposable, high cost, or have too little dissolution potential.

Ionic liquids have become a very popular and interesting group of compounds in the last dozen or so years. Initially, they were used as an alternative to volatile organic solvents. It was quickly realized that they could also be used in many fields of chemistry, pharmacy and medicine. The use of ionic liquids is mainly determined by their properties, which strictly depend on the structure of the cation and anion, so it is possible to design them in such a way as to obtain a liquid with the desired properties. In 2002, the group of prof. Rogers publishes an innovative work on the dissolution of cellulose in ionic liquids. Ionic liquids can be used both as cellulose solvents and as a medium for its further modification. The international publication WO0329329A2 describes the use of i.a. imidazolium, piperidinium and tetraalkylammonium ionic liquids in the dissolution of cellulose. The descriptions of the invention applications No. PL392867A1 and PL392868A1 disclose the use of cyclohexylammonium ionic liquids with acetic, 2-methoxyacetic, 2- (2-methoxyethoxy) acetic anions and

2- [2- (2-methoxyethoxy) ethoxy] acetic.

Composites consisting of organic and inorganic compounds are attracting more and more interest. This is due to the electrical, magnetic and optical properties of these composites, which result from the combination of the properties of their compounds. Composites are created, which include, among others metals and their oxides, e.g. titanium (IV) oxide, zinc oxide, iron (III) oxide, or gold. The greatest interest is titanium (IV) oxide, which is a promising material in photoelectronics, solar energy conversion, photocatalysis, and water and air purification. The most common carriers for these compounds are glass, ceramics or cellulose. They increase the stability of metals and their oxides while maintaining their properties.

The essence of the invention is a method of obtaining new composites of cellulose and titanium (IV) oxide with the use of cyclohexylammonium ionic liquids defined by the general formula 1, in which R is a straight-chain alkyl substituent consisting of 1 to 20 carbon atoms, or a benzyl or allyl substituent, and A is the acidic residue of acids organic compounds defined by the general formula 2, in which z is 0 or 1 or 2, wherein cellulose is dissolved in the ionic liquid at a temperature of 20 to 120 ° C, preferably at 100 ° C, in an amount of 0.05 to 30% by weight, then, after dissolving it, titanium (IV) oxide is added in an amount from 0.01 to 50% by weight, based on the amount of previously added cellulose, then the solution prepared in this way is cooled and added to it with water or an organic solvent such as methanol, ethanol, isopropanol or acetone, preferably acetone, then the precipitated composite of cellulose and titanium (IV) oxide is filtered and dried at a temperature of 20 to 60 ° C, preferably 40 ° C, for a period of 1 to 48 hours days, preferably 24 hours.

A variation of the method of obtaining cellulose and titanium (IV) oxide composites with the use of ionic liquids defined by the general formula 1, in which R is a straight-chain alkyl substituent of 1 to 20 carbon atoms, or a benzyl or allyl substituent, and A is the acid residue of organic acids defined by the general formula 2, wherein z is 0 or 1 or 2, wherein cellulose is dissolved in a solution of the ionic liquid and dimethylsulfoxide in a weight ratio of 1: (0.01-50) at a temperature of 20 to 120 ° C, preferably at 100 ° C, in an amount of from 0.05 to 60% by weight, then after its dissolution, titanium (IV) oxide is added in an amount of 0.01 to 50% by weight, based on the amount of previously added cellulose, and then the solution prepared in this way is cooled

And water or an organic solvent such as methanol, ethanol, isopropanol or acetone, preferably acetone, is added thereto, then the precipitated cellulose-titanium (IV) oxide composite is filtered and dried at a temperature of 20 to 60 ° C, preferably at 40 ° C. ° C, for a period of 1 to 48 hours, preferably 24 hours.

It is preferred that the solvent is water or methanol or ethanol or isopropanol or acetone.

Thanks to the solution according to the invention, the following technical and economic effects were obtained:

- a new method was developed to obtain composites of cellulose and titanium (IV) oxide with the use of cyclohexylammonium ionic liquids;

- new composites have better properties of absorbing UV-VIS radiation;

- new composites are thermally and chemically resistant;

- new composites can be prepared in a number of different utility forms, ranging from the standard form of powders or granules, through the form of films and coatings.

The invention is a new method for the preparation of photostable composites of cellulose and titanium (IV) oxide using cyclohexylammonium ionic liquids, as illustrated in the following examples.

P r z k ł a d I

Preparation of a composite of cellulose and TiO ₂ with (cyclohexyl) hexyldimethylammonium acetate ₃

In a round bottom flask of 100 ^cm3 equipped with a magnetic stirrer, 30 g of ethyl (cyclohexyl) heksylodimetyloamoniowego and heated to a temperature of 100 ° C. Then 1.5789 g of microcrystalline cellulose is added to the flask and stirred until it is completely dissolved. Then 0.1754 g of a titanium (IV) oxide powder with a particle size below 200 nm is added to the mixture. The mixture is stirred for 5 minutes, then the mixture is cooled and ₃ cm ^{3 of} water are added. The precipitated composite of cellulose and TiO2 is filtered off. The finished product is dried under reduced pressure at 40 ° C for 12 hours.

A composite with 98% efficiency was obtained, containing 10% TiO2.

P r z x l a d II

Preparation of a composite of cellulose and TiO ₂ with butyl (cyclohexyl) dimethylammonium 2-ethoxyacetate ₃

To the reactor with a capacity of 250 cm ³ equipped with a mechanical stirrer was added 100 g

Butyl (cyclohexyl) dimethylammonium 2-ethoxyacetate and 6.3830 g of fibrous cellulose. It was heated to 95 ° C and stirred for 2 hours. Then titanium (IV) oxide was added in quantity

0.7092 g and was stirred until a homogeneous mixture was obtained. The mixture was allowed to thistle device ₃ is added to 150 cm ³ of methanol and stirred for 30 minutes. Then, the precipitate, which is a composite of cellulose and TiO2, containing 10% of titanium (IV) oxide, is separated and dried in a vacuum oven for 4 hours at 50 ° C.

A composite with a yield of 97% was obtained, containing 10% TiO2.

P r x l a d III

Preparation of a composite of cellulose and TiO2 using butyl (cyclohexyl) dimethylammonium formate ₃

In a flat-bottomed flask with a capacity of 50 cm ³ provided with magnetic agitation provided 45 g of butyl formate (cyclohexyl) dimethylammonium chloride and 45 g of dimethylsulfoxide (DMSO) and heated to 95 ° C. 15.8824 g of microcrystalline cellulose are added and the mixture is stirred until it is completely dissolved, then 2.8028 g of TiO2 are added. After 5 minutes, the mixture is cooled and methanol added. The precipitated composite is filtered off and dried for 40 hours at 40 ° C under reduced pressure.

A composite of cellulose and TiO2 was obtained with a yield of 95%, containing 15% TiO2.

P r x l a d IV

Preparation of a composite of cellulose and TiO ₂ using 2-methoxyacetate (cyclohexyl) hexyldimethylammonium

0.3535 g of bacterial cellulose was added to a beaker containing 35 g of hexyldimethylammonium 2-methoxy (cyclohexyl) acetate. It was heated to 90 ° C, 0.0884 g of TiO2 was added and stirred for 45 minutes. Then water is added and the precipitated composite is filtered off. Then it is dried at 50 ° C for 48 hours. A composite of cellulose and TiO2 was obtained with a yield of 97%, containing 20% of TiO2.

PL 226 095 B1

P r z k ł a d V

Preparation of a composite of cellulose and TiO ₂ using 2- (2-methoxyethoxy) acetate (cyclohexyl) butyldimethylammonium ₃

In a round bottom flask of 250 cm ^{3 of} 150g of 2- (2-methoxyethoxy) ethyl (cyclohexyl) butylodimetyloamoniowego and a magnetic stirrer. The ionic liquid was intensively stirred and heated to 85 ° C, then 6.25 g of microcrystalline cellulose was slowly added. Then, 1.3258 g of TiO2 was added to the mixture and the mixture was stirred for 15 minutes. After cooling, acetone was added to the mixture, the precipitated composite was filtered and dried for 15 hours at 45 ° C under reduced pressure. A composite with a 94% efficiency was obtained, containing 17.5% TiO ₂ .

P r x l a d VI

Preparation of a composite of cellulose and TiO2 using 2- [2- (2-methoxyethoxy) ethoxy] (cyclohexyl) hexyldimethylammonium acetate

40 g of 2- [2- (2-methoxyethoxy) ethoxy] acetate (cyclohexyl) hexyldimethylammonium acetate and 20 g of DMSO were placed in a reactor equipped with a magnetic stirrer. The whole was heated to 80 ° C and 10 g of fibrous cellulose was added in portions until it was completely dissolved. Then 0.5263 g of titanium (IV) oxide was added and cooled to room temperature. To a cooled stirred for ₃ ny was poured 100 cm ³ of water. The precipitated composite was separated and dried in a vacuum oven for 24 hours.

A composite with a yield of 98% containing 5% TiO2 was obtained.

P r o x l a d VII

Properties of the photocatalytic stability of the obtained material

0.1 g of the composite of cellulose and TiO2 obtained according to Example 1, which contained 10% by weight of TiO2, was weighed into two glass beakers, and each was supplemented with 500 ml of demineralized water. The first beaker was stirred in the dark for 12 hours. After this time, an organic carbon content (TOC) analysis was performed in the filtrate. _{3 was} found in the filtrate

3.82 mg / dm ³ , derived from unfiltered cellulose composite particles.

₂

The other beaker was mixed under a UV / Vis lamp with the intensity of UV radiation 183 W / m and Vis ₂

167 W / m ² for 12 hours. After this time the analysis is performed in the filtrate an organic carbon content of ₃ Committee (TOC). The filtrate showed a slight increase in organic carbon to 4.96 mg / dm ³ , also coming from unfiltered cellulose composite particles.

P r x l a d VIII

Photocatalytic properties of the obtained material

To a glass beaker was weighed 0.1 g of the composite cellulose and TiO 2, prepared according to Example I, which typically cover 10% by weight of TiO _2. The beaker was supplemented with 500 ml of demineralized water containing ₃ RR 198 dye at a concentration of 20 mg / dm ³ . After equilibration of the adsorption, the concentration of organic carbon in the _3-border solution was approx. 8 mg / dm ^3. After 24 hours, the TOC concentration increased to approx.

₃ mg / dm ³ , which indicates the desorption of the RR198 dye, but does not confirm the photoactivity towards dye mineralization, because additionally no changes in the content of inorganic carbon (IC) in the solution are observed. Crystalline cellulose, containing no TiO _2, behaved in a similar way.

P r x l a d IX

UV radiation absorbing properties of the obtained material

A crystalline cellulose tablet for UV absorption measurement was prepared and placed in the spectrometer chamber. The measurement was performed using the UV-Vis / DR technique in the radiation range of 200 to 800 nm.

A second tablet was prepared from a composite of cellulose and TiO ₂ obtained according to Example No. 1, which contained 10% by weight of TiO ₂ . The tablet was placed in the spectrometer chamber. The measurement was performed using the UV-Vis / DR technique in the radiation range of 200 to 800 nm.

The crystalline cellulose absorbed 50% of the UV radiation up to 400 nm and only 15% of the visible radiation in the range above 400 nm. The cellulose composite with 10% TiO ₂ showed stronger absorption, because it absorbed 100% of UV radiation and 50% of visible radiation.

Claims (4)

Patent claims 1. A method for obtaining new photostable composites of cellulose and titanium (IV) oxide using cyclohexylammonium ionic liquids, characterized in that for the ionic liquid represented by the general formula 1, in which R is a straight-chain alkyl substituent consisting of 1 to 20 carbon atoms, or a benzyl substituent or allylic acid, and A acid residue of organic acids defined by general formula 2, in which z is 0 or 1 or 2, cellulose is added at a temperature of 20 to 120 ° C, preferably at 100 ° C, in an amount from 0.05 to 30 % by weight, then after dissolving it, titanium (IV) oxide is added in an amount from 0.01 to 50% by weight, based on the amount of previously added cellulose, then the solution prepared in this way is cooled and a solvent is added thereto, then the precipitated cellulose composite and The titanium (IV) oxide is filtered off and dried at a temperature of 20 to 60 ° C, preferably 40 ° C, for a period of 1 to 48 hours, preferably 24 hours. 2. A method for the preparation of new photostable composites of cellulose and titanium (IV) oxide using cyclohexylammonium ionic liquids, characterized in that for a solution of an ionic liquid represented by the general formula 1, in which R is a straight-chain alkyl substituent composed of 1 to 20 carbon atoms, or a substituent benzyl or allyl, and A is an acid residue of organic acids defined by the general formula 2, in which z is 0 or 1 or 2, and dimethylsulfoxide in a weight ratio of 1: (0.01-50) cellulose is added at a temperature of 20 to 120 ° C , preferably at 100 ° C, in an amount of 0.05 to 30% by weight, then after its dissolution, titanium (IV) oxide is added in an amount of 0.01 to 50% by weight, based on the amount of cellulose previously added, and then so the prepared solution is cooled and a solvent is added thereto, then the precipitated composite of cellulose and titanium (IV) oxide is filtered and dried at a temperature of 20 to 60 ° C, preferably at 40 ° C, for a period of 1 to 48 hours, preferably 2 4 hours. 3. The method of obtaining new photostable composites of cellulose and titanium (IV) oxide with the use of cyclohexylammonium ionic liquids according to claim 1, The process of claim 1, wherein the solvent is water or methanol or ethanol or isopropanol or acetone. 4. The method of obtaining new photostable composites of cellulose and titanium (IV) oxide using cyclohexylammonium ionic liquids according to claim The process of claim 2, wherein the solvent is water or methanol or ethanol or isopropanol or acetone.