Preparation method of fluorine-free super-hydrophobic and self-cooling synergistic silk fabric

Abstract

The invention discloses a preparation method of a fluorine-free super-hydrophobic and self-cooling synergistic silk fabric. The preparation method comprises the following steps: forming an M-O-Si bond from a silane coupling agent macromolecule and an inorganic metal oxide (MXOY) by using a covalent bond grafting method to obtain silane modified encapsulated MXOY particles; the obtained particles and amino-terminated organic silicon emulsion are subjected to an in-situ amination reaction on silk fibers to form the fluorine-free super-hydrophobic self-cooling synergistic organic-inorganic composite silk fabric. MXOY with high refractive index endows the silk fabric with a self-cooling function, and an organic silicon structure can change the roughness of the surface of the silk fabric and reduce the surface energy of the silk fabric, so that the silk fabric has fluoride-free super-hydrophobic performance. In addition, the MXOY shows better durability under the barrier action of an organic silicon structure. The fluorine-free super-hydrophobic self-cooling silk fabric prepared by the invention can be applied to the fields of high-end intelligent textiles, special protection and the like.

Description

Technical Field

[0001] The invention belongs to the field of multifunctional coatings and intelligent textiles, and relates to a method for preparing a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric. Background Art

[0002] With the development of science and technology, people's living standards have improved accordingly. In order to meet people's needs, multifunctional fabrics have gradually come into view. Fabrics are widely used in our daily lives because of their good softness, high toughness, low cost, multiple functions and easy shaping, but their hydrophilicity and easy pollution have limited their application in daily life. In addition, with the occurrence of the greenhouse effect, summer temperatures have continued to rise in recent years, and fabrics with cooling functions have become more and more popular. Most of the hydrophobic fabrics reported so far are modified using fluorine-containing compound reagents, but fluorine-containing compounds cause irreversible damage to the environment. Therefore, it is particularly important to use fluorine-free compounds to modify the surface of fabrics.

[0003] A variety of methods have been used to develop super-hydrophobic coatings and cooling materials, including chemical vapor deposition, electrospinning, hydrothermal, grafting, and dip coating. Among these methods, dip coating stands out because it can easily adjust the chemical composition required for the cooling and hydrophobic behavior of fabrics, and can use deionized water instead of organic solvents, which is cheap, safe, healthy, and pollution-free. Summary of the invention

[0004] The present invention provides a method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric. The present invention uses silk fabric as a matrix, and utilizes a covalent bond grafting method to graft silane coupling agent macromolecules and M X O Y Combined with the self-cooling performance of the encapsulated M X O Y The particles are then reacted with amino-terminated silicone emulsion and tyrosine residue protein on silk fibers to form fluorine-free super-hydrophobic, self-cooling synergistic organic-inorganic composite silk fabric. The metal particles have a high refractive index for light, giving the fabric a self-cooling function. Silicone can not only change the roughness of the fabric surface, reduce its surface energy, and make the fabric show super-hydrophobic properties, but also have an effect on the encapsulated M X O Y The particles have a barrier effect, which can reduce the wear rate of inorganic particles and make their super hydrophobic and self-cooling functions stable and long-lasting.

[0005] The present invention is achieved through the following technical solutions:

[0006] 1) Encapsulated M X O Y Preparation of particles: X O YThe mixture is mixed with a certain amount of silane coupling agent macromolecules in a beaker, and then a certain amount of non-polar solvent is added to the beaker, heated and stirred until the solvent is completely evaporated, and the obtained mixture is irradiated with ultraviolet light for a certain period of time, and then the mixture is evenly dispersed in the non-polar solvent, and the unreacted silane coupling agent macromolecules are removed by centrifugation to obtain an encapsulated MO-Si structure. X O Y particle.

[0007] 2) Preparation of fluorine-free super-hydrophobic, self-cooling synergistic organic-inorganic composite silk fabric: The encapsulated M having MO-Si structure treated in step 1) is X O Y The particles and amino-terminated silicone emulsion are ultrasonically dispersed in an appropriate amount of deionized water, the pH of the solution is adjusted to weak acidity with acid, and then a certain amount of water-soluble macromolecular aldehyde is added thereto. After stirring evenly, an appropriate amount of silk fabric is immersed in the above solution to obtain fluorine-free super-hydrophobic, self-cooling synergistic silk fabric through in-situ amination reaction.

[0008] The present invention firmly grafts the silane coupling agent macromolecules on the M through covalent bonds. X O Y The silane-modified encapsulated M with self-cooling function is obtained. X O Y The particles are then reacted with amino-terminated PDMS emulsion in the presence of water-soluble macromolecular aldehydes to form an in-situ amination reaction with silk fibers to form a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric. Metals have a high refractive index to light and can exhibit a cooling function. They can be encapsulated by silane coupling agent macromolecules through MO-Si bonds to obtain encapsulated M X O Y Particles. The encapsulated particles are in situ encapsulated on the surface of silk fibers through an in-situ amination reaction between amino-terminated PDMS and tyrosine residue proteins on the surface of silk fabrics in the presence of water-soluble macromolecular aldehydes, forming fluorine-free super-hydrophobic, self-cooling silk fabrics. The fluorine-free super-hydrophobic, self-cooling synergistic silk fabrics obtained by this method are durable and wear-resistant.

[0009] Preferably, in step 1), the metal ions include but are not limited to Al2O3, ZrO2, Fe2O3, Fe3O4, CuO, MnO2, Mn3O4, ZnO, Ag2O, SnO2, etc. These metal particles have a high refractive index and give the fabric cooling and UV resistance functions;

[0010] The molecular weight ratio of metal ions to silane coupling agent should be controlled between 0.1:1 and 4:1. This is because when the amount of metal ions is too low, the cooling effect is poor; when the amount of metal ions is too high, the softness and breathability of the fabric will be affected.

[0011] Preferably, in step 1), the silane coupling agent macromolecules include but are not limited to polymethylalkylsiloxane, polymethyltriethoxysilane, polyetherpolysiloxane copolymer, etc.

[0012] Preferably, in step 1), the non-polar solvent includes but is not limited to benzene, carbon tetrachloride, n-hexane, isooctane, toluene, dichloromethane, petroleum ether, toluene, chloroform, tetrahydrofuran, etc.;

[0013] The mass ratio of the non-polar solvent to the silane coupling agent macromolecule is controlled between 300:1 and 60:1. X O Y It is difficult to react completely with silane coupling agents; when there are more non-polar solvents, raw materials are wasted, and the use of large amounts of organic solvents will increase the environmental burden.

[0014] Preferably, in step 1), the ultraviolet irradiation time ranges from 1 hour to 5 hours. When the time is less than 1 hour, M X O Y Failure to form sufficient active molecules on the surface to undergo covalent grafting reactions with siloxane bonds to form MO-Si bonds will result in more light pollution when ultraviolet rays are irradiated for too long.

[0015] Preferably, in step 2), the organosilicon includes but is not limited to γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl)-γ-aminopropyldimethoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyldiethoxysilane, N-β (aminoethyl)-γ-aminopropyltriethoxysilane, anilinomethyltriethoxysilane, poly (dimethylsiloxane), bis (3-aminopropyl) end-capping, aminomethyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, polyaminoalkyltrialkoxysilane, etc.

[0016] Encapsulated M X O Y The mass ratio of particles to silicone should be controlled between 10:1 and 0.5:1. When the mass ratio is higher than 10:1, M X O Y The particles cannot be completely coated by the amino-terminated silicone; when the mass ratio is lower than 0.5:1, the metal particle content in the obtained composite coating is low and the cooling effect is poor.

[0017] Preferably, in step 2), the water-soluble macromolecular aldehyde includes but is not limited to glutaraldehyde, glyceraldehyde, xylose aldehyde, glucose, hydroxymethyl furfural, etc. The water-soluble macromolecular aldehyde reacts with the amino-terminated silicone emulsion and the tyrosine residue protein in the silk under weakly acidic conditions in situ amination.

[0018] Preferably, in step 2), the encapsulated M X O Y The mass ratio of particles to silk should be controlled between 0.2:1 and 2:1. When the mass ratio is lower than 0.2:1, the cooling effect is poor; when the mass ratio is higher than 2:1, the fluorine-free super-hydrophobic and self-cooling coating is too thick, and the air permeability of the silk fabric is poor.

[0019] Preferably, in step 2), the mass ratio of the amino-terminated silicone to the water-soluble macromolecular aldehyde should be controlled between 0.5:1 and 3:1. When the mass ratio is lower than 0.5:1, the amination reaction is incomplete; when the mass ratio is higher than 3:1, the excess aldehyde solution reacts with the hydroxyl groups on the surface of the silk fabric to destroy the integrity of the fabric.

[0020] Preferably, the soaking time of the silk fabric in step 2) should be controlled within 5 to 48 hours. When the soaking time is less than 5 hours, the amination reaction is incomplete; when the soaking time is more than 48 hours, the amino acid molecules on the surface of the silk are hydrolyzed, resulting in poor mechanical properties of the silk fabric.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1) The present invention uses a covalent bond grafting method to firmly graft the silane coupling agent macromolecule onto the M through the MO-Si bond. X O Y The self-cooling encapsulated M with stable structure is obtained. X O Y Particles give silk fabrics a long-term and stable self-cooling function.

[0023] 2) Encapsulate the self-cooling X O Y The particles are coated on silk fabrics with silicone, giving the silk fabrics durable super-hydrophobic and self-cooling synergistic functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a field emission scanning electron microscope image of a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric, corresponding to Comparative Example 1 (a), Comparative Example 2 (b), Comparative Example 3 (c) and Example 1 (i), Example 8 (h), Example 9 (g), Example 10 (e), Example 11 (f), Example 13 (d);

[0025] Figure 2 The data graphs of (a) air permeability and (b) cooling coefficient of silk, silk / Al2O3 and silk / Al2O3 / PDMS, a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric, and the same after rubbing for 100 times and washing with circulating water (LCs) for 50 times in Comparative Example 1 and Examples 6 to 8;

[0026] Figure 3 The water contact angle and (e) rolling angle of silk; silk / Al2O3; silk / Al2O3 / PDMS, a fluorine-free superhydrophobic, self-cooling synergistic silk fabric, in Comparative Example 1 and Examples 6 to 8, are (a) silk; (b) silk / Al2O3; (c) silk / Al2O3 / PDMS; (d) after rubbing 100 times and washing with circulating water (LCs) 50 times;

[0027] Figure 4 ATR-FTIR graphs of silk; silk / Al2O3; silk / Al2O3 / PDMS, a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric in Comparative Example 1 and Examples 6 to 8.

[0028] Figure 5 It is a schematic diagram of the preparation method of the fluorine-free super-hydrophobic, self-cooling synergistic silk fabric of the present invention. DETAILED DESCRIPTION

[0029] In order to find the optimal preparation method of the present invention, the following examples are listed to further illustrate the present invention. The examples described below are partial examples of the present invention, not all examples, and are only used to further illustrate the present invention, not to limit the present invention.

[0030] like Figure 5 As shown, a preparation method and application of a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric comprises the following steps:

[0031] 1) Encapsulated M X O Y Preparation of particles: M X O Y The mixture is mixed with a certain amount of silane coupling agent macromolecules, dissolved in a certain amount of non-polar solvent, heated and stirred until the solvent is completely evaporated, the obtained mixture is irradiated with ultraviolet light for a certain period of time, and then the mixture is dissolved in a non-polar solvent, and the unreacted silane coupling agent macromolecules are removed by centrifugation to obtain an encapsulated MO-Si structure. X O Y particle.

[0032] 2) Preparation of fluorine-free super-hydrophobic, self-cooling synergistic organic-inorganic composite silk fabric: The encapsulated M having MO-Si structure treated in step 1) is X O Y The particles and amino-terminated silicone emulsion are ultrasonically dispersed in an appropriate amount of deionized water, the pH of the solution is adjusted to a weakly acidic range, a certain amount of water-soluble macromolecular aldehyde is added thereto, and after stirring evenly, an appropriate amount of silk fabric is immersed in the above solution to obtain fluorine-free super-hydrophobic, self-cooling synergistic silk fabric through in-situ amination reaction.

[0033] The mass of silk used in each comparative example and example in the following table is 1 gram, and the raw material ratios mentioned are all mass ratios. The raw materials used in Table 1 are from the following manufacturers and models, as follows:

[0034] Polymethyltriethoxysilane: Aladdin, T103634;

[0035] Cyclomethicone: Merck, 1154707;

[0036] Aminosiloxane: Shandong SICO New Materials Co., Ltd., SICO-A110;

[0037] Polymethylphenylsiloxane: McLean, 361876;

[0038] Poly(dimethylsiloxane), bis(hydroxyalkyl) end-capped: Merck, 481246;

[0039] Water-soluble aldehyde (glucose): Merck, PHR1000.

[0040] Table 1

[0041]

[0042] Among the silk fabrics obtained in the above experiments, Comparative Examples 1 to 3 are the control group, and their hydrophobic and self-cooling properties are poor. The cooling coefficients of Comparative Examples 1 to 3 and Examples 1 to 7 are low, mainly because M X O Y Low content. The cooling coefficient of Examples 10 to 13 decreases because the thermal conductivity of Ag and Cu is greater than that of Al; in Examples 14 to 15, Al2O3 can better undergo covalent bond grafting with the silane coupling agent macromolecules because the activity of Mn is lower than that of Al. Since metal ions have a larger refractive index to light, the cooling coefficient of Examples 14 to 15 is lower than that of Example 8. In summary, Example 8 has the best effect. Example 8: Add (1g) Al2O3 to a solution of (1g) polymethyltriethoxysilane in (60g) n-hexane, heat and stir until the solvent is completely evaporated, irradiate the resulting mixture with ultraviolet light for 2h, evenly disperse the mixture in a large amount of n-hexane, and remove unreacted polymethyltriethoxysilane by centrifugation to obtain encapsulated Al2O3 particles. (4.0 g) encapsulated Al2O3 particles, (1.0 g) poly(dimethylsiloxane), bis(3-aminopropyl) end-capping, and (0.5 g) glucose were added into a large amount of deionized water, the obtained solution was stirred for 20 min, and then 1 g of silk fabric was immersed in the aqueous solution for 24 h to obtain a fluorine-free superhydrophobic, self-cooling synergistic silk fabric.

Claims

1. A method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric, characterized in that: The following steps are involved: 1)M X O Y The mixture is mixed with a silane coupling agent macromolecule, dissolved in a non-polar solvent, heated and stirred until the solvent is completely evaporated, the obtained mixture is irradiated with ultraviolet light, and then the irradiated mixture is evenly dispersed in a non-polar solvent, and the unreacted silane coupling agent macromolecule is removed by centrifugation to obtain an encapsulated MO-Si structure. X O Y particle; 2) The encapsulated M having MO-Si structure obtained in step 1) X O Y The particles and amino-terminated silicone emulsion are ultrasonically dispersed in deionized water, the pH of the solution is adjusted to a weakly acidic range, a water-soluble macromolecular aldehyde is added, and after stirring evenly, a silk fabric is immersed in the solution to obtain a fluorine-free super-hydrophobic, self-cooling synergistic silk fabric through an in-situ amination reaction; The molecular weight of the water-soluble macromolecular aldehyde is in the range of 50 to 200 g / mol.

2. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 1), the M X O Y It is Al2O3, ZrO2, Fe2O3, Fe3O4, CuO, MnO2, Mn3O4, ZnO, Ag2O or SnO2; The M X O Y The mass ratio of silane coupling agent to silane coupling agent macromolecule should be controlled between 0.1:1 and 4:

1.

3. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 1), the silane coupling agent macromolecule is polymethyl alkyl siloxane, polymethyl triethoxy silane or polyether polysiloxane copolymer.

4. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 1), the non-polar solvent is benzene, carbon tetrachloride, n-hexane, isooctane, toluene, dichloromethane, petroleum ether, chloroform or tetrahydrofuran.

5. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 1), the ultraviolet irradiation time is 1h to 5h.

6. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 2), the amino-terminated silicone in the amino-terminated silicone emulsion is one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl)-γ-aminopropyldimethoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyldiethoxysilane, N-β (aminoethyl)-γ-aminopropyltriethoxysilane, anilinomethyltriethoxysilane, poly (dimethylsiloxane), bis (3-aminopropyl) end-capping, aminomethyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, and polyaminoalkyltrialkoxysilane; The encapsulated M having MO-Si structure X O Y The mass ratio of the particles to the amino-terminated silicone in the amino-terminated silicone emulsion is 10:1 to 0.5:

1.

7. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 2), the water-soluble macromolecular aldehyde is one or more of glutaraldehyde, glyceraldehyde, xylaldehyde, glucose, hydroxymethylfurfural and the like.

8. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 2), the encapsulated M having a MO-Si structure X O Y The mass ratio of particles to silk fabric is 0.2:1 to 2:

1.

9. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 2), the mass ratio of the amino-terminated silicone to the water-soluble macromolecular aldehyde in the amino-terminated silicone emulsion is 0.5:1 to 3:

1.

10. The method for preparing fluorine-free super-hydrophobic, self-cooling synergistic silk fabric according to claim 1, characterized in that: In step 2), the soaking time of the silk fabric is 5 hours to 48 hours.

Images