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

Abstract

The present invention discloses a method for preparing a fluorine-free super-hydrophobic self-cooling synergistic silk fabric: silane coupling agent macromolecules and inorganic metal oxide (M X O Y ) Using covalent bond grafting method to form M-O-Si bond, silane-modified encapsulated M X O Y The obtained particles are reacted with amino-terminated silicone emulsion on silk fibers to form fluorine-free super-hydrophobic, self-cooling synergistic organic-inorganic composite silk fabrics. X O Y The silk fabric is endowed with self-cooling function, and the organic silicon structure can change the roughness of the silk fabric surface, reduce its surface energy, and make the silk fabric obtain fluorine-free super hydrophobic properties. X O Y Under the barrier effect of the organic silicon structure, the silk fabric shows good durability. The fluorine-free super-hydrophobic, self-cooling silk fabric produced by the present invention can be used in high-end smart textiles and special protection fields.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of multifunctional coating and smart textiles, and relates to a preparation method of fluorine-free super-hydrophobic, self-cooling and synergistic silk fabric. BACKGROUND

[0002] With the development of science and technology, people's living standards have improved accordingly. In order to meet people's needs, multifunctional fabrics gradually come into sight. Fabrics are widely used in our daily life due to their good softness, high toughness, low cost, multiple functions and easy shaping, but their hydrophilicity and easy pollution limit their application in daily life. In addition, with the occurrence of greenhouse effect, the temperature in summer has been rising in recent years, and fabrics with cooling function are becoming more and more popular. Most of the reported hydrophobic fabrics are modified by fluorine-containing compounds, 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] Chemical vapor deposition, electrospinning technology, hydrothermal method, grafting method and dip coating method and other methods have been used to develop super-hydrophobic coating and cooling materials. Among these methods, dip coating method stands out, which can easily adjust the chemical composition required for fabric cooling, hydrophobicity and other behaviors, and can use deionized water instead of organic solvents, with the characteristics of low cost, safety, health, no pollution and the like. SUMMARY

[0004] The present application provides a preparation method of fluorine-free super-hydrophobic, self-cooling and synergistic silk fabric. The present application uses silk fabric as a substrate, and uses covalent bond grafting method to graft silane coupling agent macromolecules and M X O Y particles onto the substrate, to prepare encapsulated M X O Y particles with self-cooling performance, and then perform in-situ amination reaction of the obtained particles with amino-terminated silicone emulsion and silk fiber on the loamino acid residue protein to form fluorine-free super-hydrophobic, self-cooling and synergistic organic-inorganic composite silk fabric. The metal particles have high refractive index to light, which endows the fabric with self-cooling function. The silicone not only changes the roughness of the fabric surface, reduces the surface energy, and makes the fabric exhibit super-hydrophobic performance, but also has a barrier effect on the encapsulated M X O Y particles, which can reduce the wear rate of inorganic particles, and make the super-hydrophobic and self-cooling function stable and durable.

[0005] The present application is realized by the following technical solutions:

[0006] 1) Preparation of encapsulated M X O Y particles: M X O YMixing a certain amount of silane coupling agent macromolecule in a beaker, adding a certain amount of non-polar solvent into the beaker, heating and stirring until the solvent is completely evaporated, irradiating the obtained mixture with ultraviolet light for a certain time, then uniformly dispersing the mixture in a non-polar solvent, removing the unreacted silane coupling agent macromolecule by centrifugation, to obtain a M X O Y Particle with M-O-Si structure

[0007] 2) Preparation of fluorine-free super-hydrophobic, self-cooling synergistic organic-inorganic composite silk fabric: uniformly dispersing the M X O Y Particle with M-O-Si structure and amino-terminated silicone emulsion in a proper amount of deionized water, adjusting the pH of the solution to weak acidity with acid, adding a certain amount of water-soluble macromolecular aldehyde into the solution, uniformly stirring, then soaking a proper amount of silk fabric in the above solution, to obtain fluorine-free super-hydrophobic, self-cooling synergistic silk fabric through in-situ amination reaction.

[0008] The silane coupling agent macromolecule is covalently grafted on the M X O Y , to obtain self-cooling functional silane-modified M X O Y Particle, then performing in-situ amination reaction of the particle with amino-terminated PDMS emulsion and the silk fiber in the presence of water-soluble macromolecular aldehyde, to form fluorine-free super-hydrophobic, self-cooling synergistic silk fabric. The metal has high refractive index to light, can exhibit cooling function, can be encapsulated by the silane coupling agent macromolecule through M-O-Si bond, to obtain encapsulated M X O Y Particle. The encapsulated particle is encapsulated on the surface of the silk fiber through in-situ amination reaction of the amino-terminated PDMS and the silk fabric surface on the asparagine residue protein in the presence of water-soluble macromolecular aldehyde, to form fluorine-free super-hydrophobic, self-cooling silk fabric. The fluorine-free super-hydrophobic, self-cooling synergistic silk fabric obtained by this method is durable.

[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., and these metal particles have high refractive index, which endows the fabric with cooling and ultraviolet resistance functions.

[0010] The mass ratio of metal ions to silane coupling agent macromolecule should be controlled between 0.1:1 and 4:1, because if the amount of metal ions is too low, the cooling effect is not good, and if the amount of metal ions is too high, the softness and air permeability of the fabric will be affected.

[0011] Preferably, in step 1), the silane coupling agent macromolecule includes but is not limited to polymethylalkylsiloxane, polymethyltriethoxysilane, polyether polysiloxane 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 non-polar solvent to silane coupling agent macromolecule is controlled between 300:1 and 60:1. When the non-polar solvent is less, M X O Y and the silane coupling agent cannot be completely reacted; when the non-polar solvent is more, raw materials are wasted, and the use of a large amount of organic solvent will increase the environmental burden.

[0014] Preferably, in step 1), the ultraviolet irradiation time ranges between 1h and 5h. When the time is less than 1h, M X O Y The surface cannot form enough active molecules to covalently graft the M-O-Si bond, and too long ultraviolet irradiation time produces more light pollution.

[0015] Preferably, in step 2), the organosilicon includes but is not limited to γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β(aminoethyl)-γ-aminopropyl dimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyl diethoxysilane, N-β(aminoethyl)-γ-aminopropyl triethoxysilane, phenylaminomethyl triethoxysilane, poly(dimethylsiloxane), bis(3-aminopropyl) terminated, aminomethyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, polyaminoalkyltrialkoxysilane, etc.

[0016] The encapsulated M X O Y The mass ratio of the particle and the organosilicon should be controlled between 10:1 and 0.5:1. When the mass ratio is higher than 10:1, M X O Y The particle cannot be completely coated by the amino-terminated organosilicon; 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 not good.

[0017] Preferably, in step 2), the water-soluble macromolecular aldehyde includes but is not limited to glutaraldehyde, glycerol aldehyde, xylose aldehyde, glucose, hydroxymethyl furfural, etc. The water-soluble macromolecular aldehyde and the amino-terminated organosilicon emulsion and the albumin residue protein in the silk in weak acid conditions occur in situ amination reaction.

[0018] Preferably, in step 2), the mass ratio of the encapsulated M X O Y The mass ratio of the particles to the 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 organosilicon 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, damaging the integrity of the fabric.

[0020] Preferably, the soaking time of the silk fabric in step 2) should be controlled between 5h and 48h. When the soaking time is lower than 5h, the amination reaction is incomplete; when the soaking time is higher than 48h, 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 application has the following advantages:

[0022] 1) The present application uses a covalent bond grafting method to firmly graft the silane coupling agent macromolecule to the M X O Y , through an M-O-Si bond, to obtain self-cooling encapsulated M X O Y particles with stable structure, and to endow the silk fabric with long-term stable self-cooling function.

[0023] 2) The self-cooling encapsulated M X O Y particles are coated on the silk fabric using organosilicon, endowing the silk fabric with durable super-hydrophobic and self-cooling synergistic function. BRIEF DESCRIPTION OF DRAWINGS

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

[0025] Figure 2 is a data graph of (a) air permeability and (b) cooling coefficient of the silk, silk / Al2O3, and silk / Al2O3 / PDMS of Comparative Example 1 and Examples 6-8, a fluorine-free super-hydrophobic and self-cooling synergistic silk fabric, and the silk fabric after being rubbed 100 times and washed 50 times in a circulation water (LCs);

[0026] Figure 3 Water contact angle and (e) rolling angle of a fluorine-free superhydrophobic, self-cooling synergistic silk fabric of (a) silk; (b) silk / Al2O3; (c) silk / Al2O3 / PDMS; (d) after 100 times of rubbing, 50 times of water washing (LCs);

[0027] Figure 4 ATR-FTIR diagram of a fluorine-free superhydrophobic, self-cooling synergistic silk fabric of (a) silk; (b) silk / Al2O3; (c) silk / Al2O3 / PDMS.

[0028] Figure 5 Schematic diagram of the preparation method of a fluorine-free superhydrophobic, self-cooling synergistic silk fabric. DETAILED DESCRIPTION

[0029] In order to find the optimal production method of the present application, the following examples are listed to further illustrate the present application. The following described examples are part of the present application, not all examples, only further illustrate the present application, not limit the present application.

[0030] As shown in Figure 5 , a preparation method and application of a fluorine-free superhydrophobic, self-cooling synergistic silk fabric, comprising the following steps:

[0031] 1) Preparation of encapsulated M X O Y particles: M X O Y and a certain amount of silane coupling agent macromolecules are mixed, and the mixture is 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 time, and then the mixture is dissolved in a non-polar solvent. The unreacted silane coupling agent macromolecules are removed by centrifugation to obtain encapsulated M X O Y particles with M-O-Si structure.

[0032] 2) Preparation of a fluorine-free superhydrophobic, self-cooling synergistic organic-inorganic composite silk fabric: the encapsulated M X O Y particles with M-O-Si structure treated in step 1) above and amino-terminated silicone emulsion are ultrasonically dispersed in a suitable amount of deionized water. The pH of the solution is adjusted to the weak acid range, and a certain amount of water-soluble macromolecular aldehyde is added. After stirring uniformly, a suitable amount of silk fabric is soaked in the above solution to obtain a fluorine-free superhydrophobic, self-cooling synergistic silk fabric through in-situ amination reaction.

[0033] The silk quality used in each of the following comparative examples and examples is 1 gram, and the mentioned raw material ratio is mass ratio. The raw materials of the following manufacturers and models are used in Table 1, as follows:

[0034] Poly methyl triethoxy silane: Aldrich, T103634;

[0035] Cyclo methyl siloxane: Merck, 1154707;

[0036] Amino siloxane: Shandong Silicon New Material Co., Ltd., SICO-A110;

[0037] Poly methyl phenyl siloxane: Michael, 361876;

[0038] Poly (dimethyl siloxane), bis (hydroxyalkyl) terminated: Merck, 481246;

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

[0040] Table 1

[0041]

[0042] In the silk fabric obtained in the above experiments, Comparative Examples 1-3 are the control group, and the hydrophobic and self-cooling properties are poor. The cooling coefficient of Comparative Examples 1-3 and Examples 1-7 is low, and the main reason is that the content of M X O Y is low. The cooling coefficient of Examples 10-13 decreases because the thermal conductivity of Ag and Cu is greater than that of Al; in Examples 14-15, Al2O3 can better covalently bond with the macromolecule of silane coupling agent because the activity of Mn is lower than that of Al. Since the metal ion has a large refractive index to light, the cooling coefficient of Examples 14-15 is lower than that of Example 8. In summary, the effect of Example 8 is the best. Example 8: (1g) Al2O3 is added to (1g) poly methyl triethoxy silane in (60g) n-hexane solution, heated and stirred until the solvent is completely evaporated, and the obtained mixture is irradiated with ultraviolet light for 2h. The mixture is uniformly dispersed in a large amount of n-hexane, and the unreacted poly methyl triethoxy silane is removed by centrifugation to obtain encapsulated Al2O3 particles. (4.0g) Encapsulated Al2O3 particles, (1.0g) poly (dimethyl siloxane), bis (3-aminopropyl) terminated, (0.5g) glucose are added to a large amount of deionized water, the obtained solution is stirred for 20min, and then 1g of silk fabric is immersed in the aqueous solution for 24h to obtain a fluorine-free super-hydrophobic, self-cooling 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 silane coupling agent macromolecules, 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 macromolecules are removed by centrifugation to obtain an encapsulated MO-Si structure. X O Y particle; 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 macromolecule should be controlled in the range of 0.1:1~4:1; 2) Encapsulated M with MO-Si structure obtained in step 1) X O Y The particles and amino-terminated silicone emulsion were ultrasonically dispersed in deionized water. The pH of the solution was adjusted to a weakly acidic range, and a water-soluble macromolecular aldehyde was added and stirred evenly. The silk fabric was then immersed in the solution to obtain a fluorine-free superhydrophobic, 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.

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 silane coupling agent macromolecule is polymethylalkylsiloxane, polymethyltriethoxysilane or polyetherpolysiloxane copolymer.

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 non-polar solvent is benzene, carbon tetrachloride, n-hexane, isooctane, toluene, dichloromethane, petroleum ether, chloroform or tetrahydrofuran.

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 ultraviolet irradiation time is 1 h to 5 h.

5. 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)-terminated, aminomethyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, and polyaminoalkyltrialkoxysilane; The encapsulated M with 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.

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 water-soluble macromolecular aldehyde is one or more of glutaraldehyde, glyceraldehyde, xylaldehyde, glucose, and hydroxymethylfurfural.

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 encapsulated M having a MO-Si structure X O Y The mass ratio of particles to silk fabric is 0.2:1~2:

1.

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 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.

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 silk fabric is soaked for 5 h to 48 h.

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