A preparation method of fabric MTMS / PTMS hydrophobic coating

Abstract

The present invention belongs to the technical field of organosilicon emulsions, and in particular relates to a method for preparing a fabric MTMS / PTMS hydrophobic coating. The method uses methyltrimethoxysilane and phenyltrimethoxysilane as raw materials to prepare an MTMS / PTMS silane emulsion, which is used as a fabric treatment liquid and a one-step impregnation method is adopted to prepare the fabric MTMS / PTMS hydrophobic coating. The method can simultaneously meet the two prerequisites of hydrophobicity, and the preparation method is simple and efficient. The surface morphology and chemical structure of the silane emulsion and cotton fabric are analyzed by scanning electron microscopy, infrared spectroscopy and contact angle measurement instrument. The results show that the prepared fabric MTMS / PTMS hydrophobic coating has a fabric contact angle of 144° and good hydrophobic properties.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon emulsions, and in particular to a method for preparing a fabric MTMS / PTMS hydrophobic coating. Background Art

[0002] Fabrics offer advantages such as ease of handling, low cost, good mechanical stability, biodegradability, and recyclability. However, fabrics are composed of hydrophilic fibers, which readily adhere to dirt and absorb various liquids, limiting their application and development. Methods for constructing hydrophobic coatings include various impregnation techniques, wet chemical etching, chemical deposition, spray coating, electrospinning, and plasma treatment.

[0003] Silicone has a unique structure and combines the properties of inorganic and organic materials. It has basic properties such as low surface tension, small viscosity-temperature coefficient, high compressibility, and high gas permeability. It also has excellent characteristics such as high and low temperature resistance, electrical insulation, oxidation stability, weather resistance, flame retardancy, hydrophobicity, corrosion resistance, non-toxicity, odorlessness, and physiological inertness.

[0004] How to use silicone to prepare MTMS / PTMS hydrophobic coating on fabrics is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a fabric MTMS / PTMS hydrophobic coating, so as to prepare a fabric MTMS / PTMS hydrophobic coating with excellent performance by utilizing organosilicon.

[0006] The present invention provides the following technical solutions:

[0007] A method for preparing a hydrophobic coating on a fabric MTMS / PTMS comprises the following steps:

[0008] Step 1: Sodium lauryl sulfate, isomeric alcohol ether and deionized water are pre-emulsified for 0.5 h under mechanical stirring, and then ammonia water is added to adjust the pH of the system to 8. Methyltrimethoxysilane and phenyltrimethoxysilane are added dropwise to the reaction system using a constant pressure dropping funnel. After the addition is completed, the reaction is continued for 1 h to obtain an MTMS / PTMS silane emulsion;

[0009] Step 2: Use ethanol and deionized water to clean the cotton fabric, dry it and set it aside, dilute the MTMS / PTMS silane emulsion, stir it evenly, and then treat the cotton fabric by the immersion method. Immerse the cleaned cotton fabric in the MTMS / PTMS silane emulsion, and place the impregnated cotton fabric in an oven to dry, thereby obtaining the fabric MTMS / PTMS hydrophobic coating.

[0010] The preparation method of the above-mentioned fabric MTMS / PTMS hydrophobic coating, wherein, in step 1, the conditions for mechanical stirring are: 30° C., 300 rpm.

[0011] The preparation method of the above-mentioned fabric MTMS / PTMS hydrophobic coating, wherein, in step 1, methyltrimethoxysilane and phenyltrimethoxysilane are added dropwise to the reaction system using a constant pressure dropping funnel, and the ratio of MTMS to PTMS is 2:3.

[0012] In the method for preparing the MTMS / PTMS hydrophobic coating on the fabric, in step 2, the MTMS / PTMS silane emulsion is diluted to a concentration of 5%.

[0013] The method for preparing the MTMS / PTMS hydrophobic coating on the fabric includes the following steps: in step 2, the cleaned cotton fabric is immersed in the MTMS / PTMS silane emulsion for 1 minute.

[0014] The preparation method of the above-mentioned MTMS / PTMS hydrophobic coating on the fabric, wherein, in step 2, the drying conditions in the oven are: first drying at 105°C for 1 minute, and then baking at 170°C for 20 seconds.

[0015] Compared with the prior art, the method for preparing the hydrophobic coating of MTMS / PTMS fabric provided by the present invention has the following beneficial effects:

[0016] (1) The present invention uses methyltrimethoxysilane (MTMS) and phenyltrimethoxysilane (PTMS) as raw materials to prepare MTMS / PTMS silane emulsion, which is used as a fabric treatment liquid. A one-step impregnation method is used to prepare a fabric MTMS / PTMS hydrophobic coating. This method can simultaneously meet the two prerequisites for hydrophobicity (i.e., a rough surface with a microstructure and a low surface tension compound), and the preparation method is simple and efficient.

[0017] (2) The surface morphology and chemical structure of the silane emulsion and cotton fabric were analyzed by scanning electron microscopy, infrared spectroscopy, and contact angle measurement. The results showed that the prepared MTMS / PTMS hydrophobic coating on the fabric had a contact angle of 144° and had good hydrophobic properties.

[0018] (3) The MTMS / PTMS hydrophobic coating on the fabric has good durability. After tape adhesion and sandpaper friction, the surface contact angle of the fabric is about 130°. After immersion in strong acid, strong base and NaCl solutions for 24 hours, the surface contact angle remains at 140°. After 72 hours of ultraviolet light irradiation, the surface contact angle of the fabric remains basically unchanged.

[0019] (4) The MTMS / PTMS hydrophobic coating on the fabric has good anti-fouling properties. The hydrophobic cotton fabric is not easily stained by red dye, and the droplets remain relatively intact on its surface within 60 seconds and are not easily wetted. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 (a) SEM image of MTMS / PTMS latex particles; (b, c) TEM images of particles with different reaction degrees;

[0021] Figure 2 (a1-a3) Particle size and distribution; (b1-b3) Average particle size; (c1-c3) Schematic diagram of PDI;

[0022] Figure 3 This is the appearance of MTMS / PTMS silane emulsion;

[0023] Figure 4 (a1, a2) SEM images of untreated cotton fabric; (b1, b2) SEM images of cotton fabric treated with MTMS:PTMS=4:1; (c1, c2) SEM images of cotton fabric treated with MTMS:PTMS=3:2; (d1, d2) SEM images of cotton fabric treated with MTMS:PTMS=1:1; (e1, e2) SEM images of cotton fabric treated with MTMS:PTMS=2:3; (f1, f2) SEM images of cotton fabric treated with MTMS:PTMS=1:4;

[0024] Figure 5 The statistical graph of contact angles on cotton fabrics treated with silane emulsions of different monomer molar ratios;

[0025] Figure 6 The statistical diagram of the contact angle of cotton fabric surface at different baking temperatures;

[0026] Figure 7 The statistical diagram of the contact angle of cotton fabric surface at different baking times;

[0027] Figure 8 This is a statistical diagram of the change in wettability of MTMS / PTMS hydrophobic cotton fabric under the action of tape adhesion;

[0028] Figure 9 This is a statistical diagram of the change in wettability of MTMS / PTMS hydrophobic cotton fabric under sandpaper friction;

[0029] Figure 10 The statistical diagram of the wettability of MTMS / PTMS hydrophobic cotton fabric in different pH acid and alkali solutions and NaCl solution;

[0030] Figure 11This is a statistical diagram of the wettability changes of MTMS / PTMS hydrophobic cotton fabric under ultraviolet light;

[0031] Figure 12 (a1-a3) original fabrics; (b1-b3) pictures of the anti-fouling properties of MTMS / PTMS hydrophobic cotton fabrics;

[0032] Figure 13 Images of the surface wettability of (a) original cotton fabric and (b) MTMS / PTMS hydrophobic cotton fabric. DETAILED DESCRIPTION

[0033] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0034] A method for preparing a hydrophobic coating on a fabric MTMS / PTMS comprises the following steps:

[0035] Step 1, weigh 0.17g of sodium dodecyl sulfate (SDS) and 0.34g of isomeric alcohol ether (TO-8), measure a certain amount of deionized water, add them to a 250mL four-necked flask, and pre-emulsify for 0.5h under mechanical stirring at 30°C and 300rpm. Add an appropriate amount of ammonia water to the reaction to make the pH of the system = 8. In order to control the rate of hydrolysis and polycondensation, methyltrimethoxysilane (MTMS) and phenyltrimethoxysilane (PTMS) are added dropwise to the reaction using a constant pressure dropping funnel. After the addition of the silane monomers (i.e., MTMS and PTMS) is completed, continue the reaction under the reaction conditions for 1h to obtain a stable MTMS / PTMS silane emulsion;

[0036] According to the above steps, MTMS\PTMS silane emulsions with different monomer contents (i.e., the contents of MTMS and PTMS are 5%, 20%, and 30%) and different monomer ratios (MTMS:PTMS = 4:1, 3:2, 1:1, 2:3, and 1:4) were obtained.

[0037] Step 2: First, clean the cotton fabric with ethanol and deionized water, and then dry it for use. Dilute the 30% MTMS / PTMS silane emulsion to 5% and stir evenly. Then, treat the cotton fabric by the immersion method. Immerse the cleaned cotton fabric (3cm×5cm) in 5% MTMS / PTMS silane emulsion for 1 minute. Place the impregnated cotton fabric in an oven, dry it at 105°C for 1 minute, and bake it at 170°C for 20 seconds to obtain the fabric MTMS / PTMS hydrophobic coating.

[0038] The present invention is tested and verified below:

[0039] 1.1 Macroscopic characteristics and stability of emulsions

[0040] Observe the storage stability of the silane emulsion after storing it at room temperature for one month. Dilute the 30% silane emulsion to 2.5% and let it sit for 48 hours to observe the dilution stability. Observe the high and low temperature stability of the silane emulsion by keeping it at 60°C for 48 hours and at -18°C for 3 hours, respectively, to reflect its high and low temperature resistance. Observe the silane emulsion with the naked eye to see if there is precipitation or obvious stratification. If precipitation or stratification occurs, it indicates that the silane emulsion is unstable.

[0041] 1.2 Fabric contact angle test

[0042] The contact angle of a fabric surface is measured using a contact angle tester. A 5μL drop of deionized water is placed on the fabric surface. The contact angle is measured at five different locations on each sample surface, and the average value is calculated as the contact angle of the sample. The morphology of the droplet on the fabric surface is photographed and recorded.

[0043] 1.3MTMS / PTMS coating durability test

[0044] The test uses international standard test tape (Scotch 3M 810) to carry out tape stripping experiment to explore the adhesion between substrate and hydrophobic coating. In order to make full contact between coating and tape, after tape is pasted on fabric, 100g weight is placed on tape and rolled back and forth twice. Then, uniform stripping tape is used as a cycle. After each stripping, to ensure adhesion, tape is no longer reused. After each cycle, the fabric surface contact angle is measured and recorded to evaluate the adhesion of hydrophobic coating. The experiment uses similar ISO 8251-87 method to carry out sandpaper abrasion resistance test. By observing the change of its surface contact angle after sandpaper friction, the wear resistance of hydrophobic coating is determined.

[0045] The acid, alkali and salt resistance test is to soak the MTMS / PTMS hydrophobic fabric in acid and alkali solutions of different pH values for 24 hours, and measure the changes in wettability of water droplets on its surface before and after soaking, so as to evaluate the acid, alkali and salt resistance of the MTMS / PTMS hydrophobic coating on the fabric.

[0046] To test whether the hydrophobic properties of the MTMS / PTMS coating on fabrics weaken under light exposure, the modified cotton fabric's resistance to UV radiation was tested. The samples were irradiated with a UV lamp at a fixed wavelength of 365 nm, and the water contact angle on the fabric surface was measured at 0, 6, 12, 24, 36, 48, 60, and 72 hours.

[0047] 1.4MTMS / PTMS coating anti-pollution test

[0048] The anti-fouling properties of the fabrics were evaluated using a reactive red dye solution as the contaminant. Different samples were immersed in the reactive red dye solution for 1 minute and then removed. The samples were washed with deionized water and then dried. The surface conditions of the original and modified fabrics were recorded before, after, and after immersion and washing.

[0049] Red dye was dropped on the original cotton fabric and the modified cotton fabric, and the wettability changes of the droplet were observed and recorded within 0-60s.

[0050] Test and verification results:

[0051] 2.1 Emulsion micromorphology

[0052] Figure 1 The scanning electron microscope and transmission electron microscope images of MTMS / PTMS silane emulsion are shown in Figure 2. Figure 1 It can be seen from (a) that the latex particles are spherical in shape and the spherical latex particles are stacked on each other, which can provide a certain roughness to the substrate surface. Figure 1 (b, c) It can be observed that the spherical latex particles are uniform in size and there are certain connections between the latex particles.

[0053] 2.2 Emulsion particle size and distribution

[0054] In general, the better the dispersion of the emulsion, the narrower and more uniform the particle size distribution. Therefore, the particle size can reflect the dispersion of the emulsion. The MTMS / PTMS silane emulsions with different contents and molar ratios were characterized using a dynamic light scattering nanoparticle size analyzer. The effects of the amount and molar ratio of MTMS and PTMS on particle distribution, average particle size and polydispersity index (PDI) were investigated. The experimental results are shown in Figure 2. Figure 2 As shown. The width of the particle size distribution reflects the uniformity of the particle size. The smaller the particle size distribution width, the better the uniformity of the particle size distribution. Figure 2 In a1-a3 and b1-b3, when the silane emulsion monomer content is the same, as the PTMS content increases, the particle size and distribution of the MTMS / PTMS latex particles decrease. The larger the monomer content, the larger the size and distribution of the latex particles. Figure 2 As can be seen from the PDI values of c1-c3, all MTMS / PTMS materials have a PDI value <0.1. When the PDI is <0.1, the material can be considered a monodisperse system. A high monomer content leads to an increase in molecules within the system. This increases the number of silanols and oligomers at the interface between the oil and water phases. This ultimately leads to an increase in the size and distribution of the latex particles. The presence of organic groups also affects the hydrolysis and polycondensation of silanes. The steric hindrance of the phenyl group hinders the hydrolysis and condensation rate of the silane monomer, resulting in a smaller particle size distribution.

[0055] 2.3 Emulsion stability

[0056] Observe the appearance of MTMS / PTMS silane emulsion, such as Figure 3 As shown. When MTMS:PTMS = 4:1, 3:2, and 1:1, the emulsion appears milky white. As the PTMS content increases, when MTMS:PTMS = 2:3 and 1:4, the emulsion becomes translucent and has a blue glow. The stability of 30% silane emulsion was analyzed by storage, dilution, centrifugation, high and low temperature methods (Table 1), and the silane emulsion has good stability. Stability increases with increasing PTMS content. It has a certain relationship with particle size and distribution. The trend of emulsion stability is basically consistent with the particle size distribution law.

[0057] Table 1 Stability of MTMS / PTMS silane emulsion

[0058]

[0059] Note:√: The emulsion has good stability; ×: The emulsion has precipitation or stratification.

[0060] 2.4 Morphology of MTMS / PTMS hydrophobic coating

[0061] Using cotton fabric as the substrate, the surface micromorphology of the fabric treated with different silane emulsions was observed by scanning electron microscopy. In order to characterize the effect of the ratio of MTMS and PTMS monomers on the hydrophobic coating, the surface morphology of the original cotton fabric and the hydrophobic fabric treated with silane emulsions of five different monomer ratios were tested. The images of the cotton fabric surface at 1000 times and 5000 times magnification are shown in Figure 2. Figure 4 shown.

[0062] Scanning electron microscope images show that appropriately increasing the monomer content of PTMS not only creates micro-nanostructures on the fabric surface, but also improves the bonding strength between the coating and the fiber.

[0063] 2.5 Effect of preparation process on the wettability of MTMS / PTMS hydrophobic coating on fabrics

[0064] (1) Effect of the ratio of MTMS and PTMS monomers on the wettability of MTMS / PTMS hydrophobic coatings on fabrics

[0065] In the preparation process of MTMS / PTMS hydrophobic coating on fabric, low surface energy substances have a great influence on the hydrophobicity of the coating. In order to explore the effect of the molar ratio of MTMS and PTMS monomers on the hydrophobicity of the coating, Figure 5As shown in the figure, the contact angle of the cotton fabric surface first increases and then decreases as the MTMS / PTMS ratio decreases. The contact angle of the untreated cotton fabric surface is 0. When the MTMS:PTMS ratio is 4:1, the contact angle of the cotton fabric surface is 141°; when the MTMS:PTMS ratio is 3:2, the contact angle is 142°; when the MTMS:PTMS ratio is 1:1, the contact angle is 144°; when the MTMS:PTMS ratio is reduced to 2:3, the contact angle reaches a maximum of 145°; and when the MTMS:PTMS ratio is reduced to 1:4, the contact angle drops to 143°.

[0066] (2) Effect of baking temperature on the wettability of MTMS / PTMS hydrophobic coating on fabrics

[0067] To prepare the hydrophobic MTMS / PTMS coating on fabric, after impregnating the cotton fabric with the silane emulsion, it needs to be heated to enhance the bonding of the polysiloxane to the fiber. To determine the optimal heating temperature, five control experiments were conducted at 20°C intervals across a temperature range of 110°C to 190°C, using cotton fabrics treated with the same MTMS / PTMS ratio as samples. Only the heating conditions were varied. The optimal heating temperature for the coating was determined based on the change in contact angle on the cotton fabric surface.

[0068] Figure 6 The change of contact angle of cotton fabric surface at different heating temperatures. Figure 6 As can be seen from the figure, at both 110°C and 130°C, the contact angle was 139°. At 150°C, the contact angle reached 141°. At 170°C, the contact angle reached a maximum of 144°. As the temperature continued to rise, the contact angle showed little change and decreased slightly. The coating surface exhibited optimal hydrophobicity at 170°C.

[0069] (3) Effect of baking time on the wettability of MTMS / PTMS hydrophobic coating on fabrics

[0070] In actual production, excessively high temperatures not only lead to energy loss and increased manufacturing costs, but also damage the structure of cotton fabrics. While maintaining the fabric's hydrophobicity and reducing costs, this issue was addressed by lowering the heating temperature and extending the heating time. Six control experiments were conducted at 170°C, varying only the heating time with 10-second intervals, ultimately determining the optimal heating time.

[0071] from Figure 7As can be seen from the figure, when the heating time is 10 seconds, the contact angle is 142°; when the time is extended to 20 seconds, the contact angle is 144°; when the heating time is 30 seconds, the contact angle is still 144°; as the heating time continues to increase, the contact angle begins to decrease slightly, maintaining at 143°. When the heating time is 20 seconds, the contact angle of the fabric surface is the largest.

[0072] 2.6 Durability of MTMS / PTMS hydrophobic coating on fabrics

[0073] (1) Mechanical durability

[0074] To study the adhesion between the hydrophobic coating and the substrate, the coating was subjected to repeated tape peeling tests. Figure 8 As shown in Figure 2, the initial contact angle of the MTMS / PTMS hydrophobic cotton fabric was 143°. As the tape was peeled off, the contact angle of the fabric surface generally decreased. After 10 cycles of repeated tape adhesion and peeling, the water contact angle of the hydrophobic cotton fabric decreased to 133°, indicating that the fabric surface still retained its hydrophobic properties.

[0075] The coating was subjected to a sandpaper polishing test, and the contact angle of a water droplet on the surface of the MTMS / PTMS hydrophobic cotton fabric was as follows: Figure 9 As shown in the figure, the contact angle slowly decreases with increasing friction distance, from an initial 145° to 144°. Further increases in friction distance also gradually reduce the contact angle, ultimately reaching 130°, at which point the fabric surface remains hydrophobic. This indicates that the hydrophobic coating exhibits a certain degree of wear resistance under sandpaper friction. This can be attributed to the network structure formed by cross-linking the siloxane. The -OH groups of MTMS / PTMS react with the -OH groups on the surface of the cotton fabric substrate, enhancing the adhesion between the coating and the substrate.

[0076] (2) Acid, alkali and salt resistance

[0077] In real-world applications, hydrophobic materials may be damaged by engineering chemicals. In order to explore whether MTMS / PTMS hydrophobic fabrics can maintain hydrophobic stability in harsh environments of strong acid, strong base, and salt, the experiment simulated the special environmental conditions that may be experienced in actual work by using acid and base solutions and NaCl solutions of different pH values. Figure 10 shown.

[0078] Prolonged immersion in strong acid, strong base, and NaCl solutions can affect the hydrophobicity of hydrophobic cotton fabrics, causing a decrease in contact angle. In alkaline solutions with a pH of 13, the water contact angle on the cotton surface decreases significantly. After 24 hours of immersion, the contact angle decreases from 142° to 136°, but the cotton surface still retains its hydrophobic properties. In comparison, the water contact angle changes little in acidic and alkaline solutions of other pH values and in NaCl.

[0079] When the surface of the hydrophobic cotton fabric comes into contact with an aqueous solution, a protective layer similar to an air layer will form on the surface of the cotton fabric due to the presence of hydrophobic substances and rough structures, which slows down the intrusion rate of the corrosive medium in the solution. In strong acid and NaCl solutions, the hydrophobicity of the MTMS / PTMS coating is relatively stable, and in strong alkali solutions, the contact angle decreases to a certain extent. The reason may be that under the action of long-term wetting, a large amount of -OH in the strong alkali solution will react with the hydroxyl groups in the polysiloxane on the surface of the coating, causing the surface micro-nano rough structure to be destroyed, affecting the hydrophobicity of the coating. Tests have shown that the hydrophobic cotton fabric can maintain super-hydrophobic stability for at least 24 hours in different acid and alkali solutions and NaCl solution. The test results show that the MTMS / PTMS hydrophobic coating has good acid, alkali and salt resistance.

[0080] (3) UV resistance

[0081] The UV radiation resistance performance of MTMS / PTMS hydrophobic coating was tested, and the results are as follows Figure 11 As shown. The initial water contact angle on the surface of the hydrophobic cotton fabric sample was 143°. During the 12-hour UV irradiation of the sample, the surface water contact angle did not change significantly. After 72 hours of irradiation, the contact angle of the fabric surface showed a downward trend, reaching 140°, and the cotton fabric still showed excellent hydrophobicity. The experimental results show that UV irradiation has no significant effect on the hydrophobicity of cotton fabric, indicating that the MTMS / PTMS hydrophobic coating prepared in this paper has good UV radiation resistance.

[0082] 2.7 Antifouling properties of MTMS / PTMS hydrophobic coating on fabrics

[0083] In reality, the external environment is often complex and diverse. Orange juice, coffee, dyes, and soy milk often stain fabrics. Therefore, excellent wetting and anti-pollution capabilities are of great significance for practical applications. The anti-pollution capabilities of original cotton fabrics and modified cotton fabrics were evaluated using reactive red dye as the pollutant. The corresponding results are shown in Figure 2. Figure 12 and Figure 13 As shown. The original cotton cloth was dyed red with red dye ( Figure 12 a), but hydrophobic cotton fabrics have poor affinity for red dyeing ( Figure 12 b), hydrophobic cotton fabric has better anti-fouling performance. When the dye solution is dropped on the surface of the fabric, the original cotton fabric is instantly saturated, such as Figure 13 As shown in a, the droplet remains relatively intact on the hydrophobic cotton fabric, and the fabric surface is still not wetted after 60 seconds, as shown in Figure 13 As shown in b, the hydrophobic cotton fabric can remain in a non-wetting state for a longer period of time.

[0084] In summary, the method for preparing the hydrophobic coating of MTMS / PTMS fabric provided by the present invention has the following beneficial effects:

[0085] (1) The present invention uses methyltrimethoxysilane (MTMS) and phenyltrimethoxysilane (PTMS) as raw materials to prepare MTMS / PTMS silane emulsion, which is used as a fabric treatment liquid. A one-step impregnation method is used to prepare a fabric MTMS / PTMS hydrophobic coating. This method can simultaneously meet the two prerequisites for hydrophobicity (i.e., a rough surface with a microstructure and a low surface tension compound), and the preparation method is simple and efficient.

[0086] (2) The surface morphology and chemical structure of the silane emulsion and cotton fabric were analyzed by scanning electron microscopy, infrared spectroscopy, and contact angle measurement. The results showed that the prepared MTMS / PTMS hydrophobic coating on the fabric had a contact angle of 144° and had good hydrophobic properties.

[0087] (3) The MTMS / PTMS hydrophobic coating on the fabric has good durability. After tape adhesion and sandpaper friction, the surface contact angle of the fabric is about 130°. After immersion in strong acid, strong base and NaCl solutions for 24 hours, the surface contact angle remains at 140°. After 72 hours of ultraviolet light irradiation, the surface contact angle of the fabric remains basically unchanged.

[0088] (4) The MTMS / PTMS hydrophobic coating on the fabric has good anti-fouling properties. The hydrophobic cotton fabric is not easily stained by red dye, and the droplets remain relatively intact on its surface within 60 seconds and are not easily wetted.

[0089] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a fabric MTMS / PTMS hydrophobic coating, characterized in that: The following steps are involved: Step 1: Sodium lauryl sulfate, isomeric alcohol ether and deionized water are pre-emulsified for 0.5 h under mechanical stirring, and then ammonia water is added to adjust the pH of the system to 8. Methyltrimethoxysilane and phenyltrimethoxysilane are added dropwise to the reaction system using a constant pressure dropping funnel. After the addition is completed, the reaction is continued for 1 h to obtain an MTMS / PTMS silane emulsion; Step 2: Use ethanol and deionized water to clean the cotton fabric, dry it and set it aside, dilute the MTMS / PTMS silane emulsion, stir it evenly, and then treat the cotton fabric by the immersion method. Immerse the cleaned cotton fabric in the MTMS / PTMS silane emulsion, and place the impregnated cotton fabric in an oven to dry, thereby obtaining the fabric MTMS / PTMS hydrophobic coating.

2. The method for preparing the MTMS / PTMS hydrophobic coating of fabric according to claim 1, wherein In step 1, the mechanical stirring conditions are: 30°C, 300 rpm.

3. The method for preparing the hydrophobic coating of fabric MTMS / PTMS according to claim 1, wherein In step 1, methyltrimethoxysilane and phenyltrimethoxysilane are added dropwise to the reaction system using a constant pressure dropping funnel, and the molar ratio of MTMS to PTMS is 2:

3.

4. The method for preparing the hydrophobic coating of fabric MTMS / PTMS according to claim 1, wherein In step 2, the MTMS / PTMS silane emulsion is diluted to make the concentration of the MTMS / PTMS silane emulsion 5%.

5. The method for preparing the MTMS / PTMS hydrophobic coating on fabric according to claim 1, wherein In step 2, the cleaned cotton fabric was immersed in the MTMS / PTMS silane emulsion for 1 min.

6. The method for preparing the MTMS / PTMS hydrophobic coating on fabric according to claim 1, wherein: In step 2, the drying conditions in the oven are: first drying at 105°C for 1 min, and then baking at 170°C for 20 s.

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