Preparation method of self-cleaning textile coating with underwater soil release function

Abstract

The invention discloses a preparation method of a self-cleaning textile coating with an underwater easy-to-decontaminate function, and belongs to the technical field of textile fabrics. The method comprises the following steps: selecting a fabric, and carrying out pretreatment; the preparation method comprises the following steps: mixing ammonium hydroxide and ethanol, then adding tetraethyl orthosilicate, and reacting to obtain a reaction solution; soaking the pretreated fabric in a reaction solution to complete construction of a super-hydrophilic inorganic layer; and sequentially putting the fabric into the NaCl solution of the polycation electrolyte and the NaCl solution of the polyanion electrolyte for soaking, washing and drying to finish the construction of the polyelectrolyte layer on the fabric, so as to obtain the self-cleaning textile coating with the underwater easy-to-decontaminate function. The coating prepared by the invention has excellent self-cleaning performance and good surface durability, and can quickly remove oil pollutants from water.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of textile fabrics, and particularly relates to a preparation method of a self-cleaning textile coating with underwater easy stain removal function. BACKGROUND

[0002] With the development of science and technology, the application of intelligent self-cleaning technology of textiles in daily life is becoming more and more widespread. However, the current self-cleaning technology mainly achieves the stain-proof effect through the super-hydrophobic finishing of the product (similar to an umbrella, stains cannot enter). However, most of the products we use in daily life need to be hydrophilic. Therefore, the application of the above technology is very limited. How to impart self-cleaning function to textiles through post-finishing process, so that they have easy stain removal characteristics and meet the needs of the textile industry, has become a problem to be solved.

[0003] The existing super-hydrophilic surface has many problems: for example, the rough surface constructed by using conventional nanoparticles has poor weather resistance and film forming effect, and is easily affected by the environment and loses hydrophilic effect. The polymer material also has the problems of high preparation cost, and some modified reagents may be harmful to the environment. For example, titanium dioxide nanoparticles decompose the organic matter (such as polymer binder) of the nanoparticles and the substrate under ultraviolet light excitation, resulting in a decrease in the bonding force between the nanoparticles and the substrate, and the collapse of the film structure. Fluorine-containing polymers (such as perfluorooctanoic acid, PFOA) use modified reagents with persistence, bioaccumulation and toxicity (PBT characteristics), which are difficult to degrade in the natural environment, causing long-term burden to the ecological system, and have been listed as potential carcinogens by international organizations. In addition, during the production process of polyacrylamide (PAM), the monomer acrylamide has strong neurotoxicity, and the residual monomer needs to be removed through a complex purification process, significantly increasing the production cost.

[0004] A Chinese invention patent with application publication number CN109593390A discloses a titanium dioxide-organic composite self-cleaning coating with high light transmittance and persistent super-hydrophilic property and a mild preparation method thereof. The titanium dioxide modified with alcohol amine is directly dispersed in an acrylate monomer, and a titanium dioxide-organic composite coating is obtained by spin coating and ultraviolet curing. The ultraviolet light curing cost of the coating is high, and the spin coating process is only suitable for small substrates and cannot be used for large-scale production. SUMMARY

[0005] In view of the above technical problems, the present application provides a preparation method of a self-cleaning textile coating with underwater easy stain removal function. The coating prepared by the method has excellent self-cleaning performance and good surface durability, and has the advantages of simple process and large-scale production.

[0006] The technical solution adopted by the present application is:

[0007] The preparation method of a self-cleaning textile coating with underwater easy stain removal function comprises the following steps:

[0008] a. Constructing a super-hydrophilic inorganic layer on the fabric;

[0009] a1. Selecting a fabric and performing pretreatment;

[0010] a2. Mixing ammonium hydroxide and ethanol, then adding tetraethyl orthosilicate to react to obtain a reaction solution;

[0011] a3. Soaking the pretreated fabric in step a1 in the reaction solution obtained in step a2;

[0012] b. Constructing a polyelectrolyte layer;

[0013] b1. Soaking the fabric treated in step a in a NaCl solution of a polycationic electrolyte, rinsing with water after soaking, and drying; then soaking in a NaCl solution of a first polyanionic electrolyte, rinsing with water after soaking, and drying;

[0014] b2. Soaking the fabric treated in step b1 in a Na2SO4 aqueous solution, rinsing with water after soaking, and drying; then soaking in a NaCl solution of a second polyanionic electrolyte, rinsing with water after soaking, and drying, to complete the construction of the polyelectrolyte layer on the fabric, and obtain a self-cleaning textile coating with underwater easy stain removal function.

[0015] Preferably, in step a1, the pretreatment process is as follows: the fabric is ultrasonically cleaned with ethanol and deionized water multiple times in sequence, then dried, and then the fabric is subjected to plasma treatment, with the plasma treatment time controlled to be 20-30 minutes.

[0016] Preferably, in step a2, the reaction process is carried out at room temperature, ultrasonic treatment is carried out during the reaction process, and the reaction time is maintained for 2-3 hours.

[0017] Preferably, in step a3, the reaction solution obtained in step a2 is placed for 12-24 hours, and then the pretreated fabric in step a1 is soaked in the reaction solution, with the soaking time controlled to be 1-2 hours.

[0018] Preferably, in step b1: the polycationic electrolyte in the NaCl solution is polydimethyl diallyl ammonium chloride; the concentration of the polydimethyl diallyl ammonium chloride in the NaCl solution of the polycationic electrolyte is 1.0-1.5 mg / mL, and the concentration of NaCl is 0.4-0.5 M; the soaking time is controlled to be 20-30 minutes, the water rinsing time is controlled to be 10-15 minutes, and the drying is performed in vacuum for 10-15 minutes.

[0019] Preferably, in step b1: the first polyanionic electrolyte in the NaCl solution is sodium polystyrene sulfonate; the concentration of the sodium polystyrene sulfonate in the NaCl solution of the first polyanionic electrolyte is 0.8-1.2 mg / mL, and the concentration of NaCl is 0.4-0.6 M; the soaking time is controlled to be 10-30 minutes, the water rinsing time is controlled to be 10-15 minutes, and the drying is performed in vacuum for 10-15 minutes.

[0020] Preferably, in step b2: the concentration of the Na2SO4 aqueous solution is 100-120 mM, and the fabric is soaked in the Na2SO4 aqueous solution for 1-1.5 hours; after the soaking and rinsing, the fabric is dried in vacuum for 10-15 minutes.

[0021] Preferably, in step b2: the second polyanionic electrolyte in the NaCl solution is sodium polyvinyl sulfonate; the concentration of the sodium polyvinyl sulfonate in the NaCl solution of the second polyanionic electrolyte is 0.5-1.0 mg / mL, and the concentration of NaCl is 0.4-0.6 M; the soaking time is controlled to be 10-30 minutes, the water rinsing time is controlled to be 10-15 minutes, and the drying is performed in vacuum for 10-15 minutes.

[0022] Preferably, in step b: the fabric is repeatedly soaked, rinsed with water, and dried in the NaCl solution of the polycationic electrolyte and the NaCl solution of the first polyanionic electrolyte to perform a deposition cycle of the polycationic electrolyte and the first polyanionic electrolyte; the fabric is repeatedly soaked, rinsed with water, and dried in the NaCl solution of the second polyanionic electrolyte to perform a deposition cycle of the second polyanionic electrolyte, so as to realize the construction of the multilayer of the polyelectrolyte on the surface of the fabric.

[0023] The self-cleaning textile coating obtained by the above method can realize the underwater self-cleaning performance, and the self-cleaning efficiency after the water rinsing is 88.97%-92.68%.

[0024] The beneficial technical effects of the present application are as follows:

[0025] The present application constructs the super-hydrophilic inorganic layer and polyelectrolyte multilayer on the fabric, forms the super-hydrophilic polyelectrolyte multilayer adsorption framework through the spatial folding expansion effect of the inorganic nanometer skeleton on the surface layer of the fabric, and realizes the underwater self-cleaning function of the textile through the structured hydrophilic ion multiple hydration network structure. The coating prepared by the method has excellent self-cleaning performance and good surface durability, and can quickly remove oil pollutants from water.

[0026] Specifically,

[0027] (1) In the process of preparing the hydrophilic structure, the organic and inorganic materials are mixed to construct a nano 3D network structure, which effectively improves the shortcomings of poor durability of inorganic materials and difficult realization of super-hydrophilic effect of organic materials, and realizes the advantages of both materials on the super-hydrophilic coating.

[0028] (2) The self-cleaning textile coating prepared by the present application has super-high surface water permeability and surface hydrophilicity; the fabric wettability is described according to WCA, because of the rich hydrophilic functional groups on the surface, the WCA of the coating rapidly decreases to 0° within 1-2s.

[0029] (3) The self-cleaning textile coating prepared by the present application has excellent water washing resistance. Referring to GB / T12490-2014 "Textile color fastness test for color fastness to domestic and commercial washing", the coating can be effectively washed for more than 30 times in the washing color fastness tester.

[0030] (4) The self-cleaning textile coating prepared by the present application has excellent underwater oil-repellent performance. As can be seen from the results of the dynamic underwater oil resistance experiment, when the oil droplets contact the surface of the fabric, they will fall off from the needle and adhere to the surface of the film, and the underwater oil contact angle can reach 120°-130°.

[0031] (5) The super-hydrophilic self-cleaning textile coating prepared by the present application has wide application prospects in the fields of biomedical, antifouling, etc., especially in daily life clothing, outdoor sports clothing, etc. The preparation method of the present application has the advantages of simple process, large-scale production and high universality. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 SEM images of the micro-morphology structure of the self-cleaning textile coating prepared in the specific embodiments of the present application; wherein (a) is polyester, (b) is viscose, and (c) is cotton;

[0033] Figure 2 The shape change of water droplets on the polyester coating fabric of the present application;

[0034] Figure 3 The contrast images of the coating prepared in the specific embodiment of the present application before and after self-cleaning test;

[0035] Figure 4 The underwater oil-repellent performance image of the coating prepared in the specific embodiment of the present application;

[0036] Figure 5 The self-cleaning efficiency graph of the coating whiteness retention test;

[0037] Figure 6 The washing resistance efficiency curve graph of the coating fabric. DETAILED DESCRIPTION

[0038] The present application discloses a preparation method of a self-cleaning textile coating with underwater easy stain removal function, comprising the following steps:

[0039] (1) under alkaline conditions, hydrolyze tetraethyl orthosilicate and deposit it on the surface of the fabric to form an ultra-hydrophilic inorganic layer with rough microstructure; (2) combine the sulfonate polyanion electrolyte with strong hydration capacity with the related cations to build an ultra-hydrophilic polyelectrolyte multilayer structure. That is, build the polyelectrolyte multilayer on the surface of the fabric: specifically, repeat the deposition of PDADMAC (polydimethyl diallyl ammonium chloride) / PSS (sodium polystyrene sulfonate) chains on the fabric; then repeat the deposition of PVS (sodium polyvinyl sulfonate) chains on the fabric coated with PDADMAC / PSS to form a polyelectrolyte multilayer. The present application successfully realizes the easy stain removal and self-cleaning function through the organic combination of organic and inorganic materials, combined with chemical cross-linking and hydrophilic modification technology. Compared with traditional water-repellent and oil-repellent coatings, the present application overcomes the defect that once stained with oil stains, it is difficult to clean with water, and realizes the spontaneous peeling of oil stains under the action of water by using the ultra-hydrophilic property, showing excellent self-cleaning effect. The method has excellent adaptability to conventional hydrophilic fabrics such as polyester, viscose and cotton, and can be particularly applied to easily contaminated parts such as shirt collars, and its fast stain removal property (cleaning efficiency > 92% within 30 seconds) precisely matches the core demand of consumers for high-efficiency cleaning. Based on this, the self-cleaning coating has considerable application potential in daily life clothing, outdoor sports clothing and other scenes.

[0040] The present application will be further described in combination with specific embodiments:

[0041] Example 1

[0042] (1) First, clean the fabric (cotton, polyester, viscose) with ethanol and deionized water by ultrasonic wave for at least 3 times to remove possible contaminants, and dry at 65℃. Then, perform plasma treatment on the fabric for 20 minutes to remove possible oil, dust and other impurities on the surface of the fabric, and make the surface of the fabric full of hydroxyl groups.

[0043] (2) In a well dispersed mixture of 4 mL of ammonium hydroxide and 100 mL of ethanol, 4 mL of tetraethyl orthosilicate (TEOS) was added rapidly to trigger the synthesis of SNPs. All processes were carried out at room temperature and using 40 kHz sonication. The reaction was left for 2 hours and then left overnight. The fabric was again immersed in the post reaction mixture for 1 hour.

[0044] (3) The treated fabric (cotton, polyester, viscose) was immersed in a solution of poly cationic electrolyte NaCl, for 20 minutes, i.e. in 1.0 mg / mL of polydimethyldiallylammonium chloride (PDADMAC), 0.5 M NaCl aqueous solution for 20 minutes, followed by thorough washing with water for 10 minutes and drying in vacuum for 10 minutes. Subsequently, the PDADMAC coated fabric was immersed in a solution of poly anionic electrolyte NaCl, for 20 minutes, i.e. in 1.0 mg / mL of poly(styrene sulfonate) sodium salt (PSS), 0.5 M NaCl aqueous solution for 20 minutes, followed by thorough washing with water for 10 minutes and drying in vacuum for 10 minutes. The film at this point was designated as PDADMAC / PSS1. The deposition cycle was repeated to produce PDADMAC / PSS 3.5 polyelectlectrolyte multilayer. The polyelectrolyte multilayer is PDADMAC and PSS are deposited repeatedly; subscript 3.5 is to represent that it is repeated 3.5 times, i.e. 3.5 PDADMAC / PSS polyelectrolyte layers are deposited, i.e. 4 times PDADMAC and 3 times PSS are deposited.

[0045] The PDADMAC / PSS 3.5 fabric was immersed in a solution of Na2SO4(100 mM) in water for 1 hour, followed by thorough washing with water and drying in vacuum for 10 minutes. The resulting PDADMAC / PSS 3.5 with SO4 -2 ions as surface counterions.

[0046] The resulting PDADMAC / PSS 3.5 coated fabric was immersed in a solution of poly anionic electrolyte NaCl, for 20 minutes, i.e. in 1.0 mg / mL -1 of polyvinyl sulfonate sodium salt (PVS), 0.5 M NaCl aqueous solution for 20 minutes, followed by thorough washing with water for 10 minutes and drying in vacuum for 10 minutes. The deposition cycle was repeated 3 times to produce PDADMAC / PSS 3.5 PVS3 polyelectrolyte multilayer.

[0047] Example 2

[0048] (1) The fabric (cotton, polyester, viscose) was first cleaned with ethanol and deionized water by ultrasonic washing at least 3 times to remove possible contaminants and dried at 65°C. The fabric was then treated with plasma for 20 minutes to remove possible oils, dust and other impurities present on the surface and to make the fabric surface rich in hydroxyl groups.

[0049] (2) In a well dispersed mixture of 4 mL of ammonium hydroxide and 100 mL of ethanol, 4 mL of tetraethyl orthosilicate (TEOS) was added rapidly to trigger the synthesis of SNPs. All the processes were carried out at room temperature and using ultrasonic treatment at 40 kHz. The reaction was maintained for 2 hours and then left for at least overnight. The fabric was then immersed in the solution after the reaction for 1 hour.

[0050] (3) The treated fabric (cotton, polyester, viscose) was immersed in a solution of polycationic electrolyte NaCl for 20 minutes, i.e. in a solution of 1.2 mg / mL of polydimethyldiallylammonium chloride (PDADMAC), 0.4 M NaCl in water for 20 minutes, then washed thoroughly with water for 10 minutes and dried in vacuum for 10 minutes. Subsequently, the fabric coated with PDADMAC was immersed in a solution of polyanionic electrolyte NaCl for 20 minutes, i.e. in a solution of 0.8 mg / mL of sodium polystyrene sulfonate (PSS), 0.5 M NaCl in water for 20 minutes, then washed thoroughly with water for 10 minutes and dried in vacuum for 10 minutes. The film at this point was called PDADMAC / PSS1. The deposition cycle was repeated to produce PDADMAC / PSS 3.5 polyelectrolyte multilayers on the fabric.

[0051] The PDADMAC / PSS 3.5 fabric was immersed in a solution of Na2SO4(100 mM) in water for 1 hour, then washed thoroughly with water and dried in vacuum for 10 minutes. The resulting PDADMAC / PSS 3.5 with SO4 -2 ions as surface counterions.

[0052] The PDADMAC / PSS 3.5 coated fabric was immersed in a solution of polyanionic electrolyte NaCl for 20 minutes, i.e. in a solution of 1.0 mg / mL -1 of sodium polyvinyl sulfonate (PVS), 0.5 M NaCl in water for 20 minutes, then washed thoroughly with water for 10 minutes and dried in vacuum for 10 minutes. The deposition cycle was repeated 3 times to produce PDADMAC / PSS 3.5 PVS3 polyelectrolyte multilayers on the fabric.

[0053] Comparative Example 1

[0054] (1) The fabric (cotton, polyester, viscose) was first cleaned with ethanol and deionized water by ultrasonic washing at least 3 times to remove possible contaminants and dried at 65°C. The fabric was then plasma treated for 20 minutes to remove possible oils, dust and other impurities present on the surface and to make the fabric surface rich in hydroxyl groups.

[0055] (2) Then 4 mL of TEOS was quickly added to trigger the synthesis of SNPs in a well dispersed mixture of 4 mL of ammonium hydroxide and 100 mL of ethanol. All processes were carried out at room temperature and using ultrasonic treatment at 40 kHz. The reaction was maintained for 2 hours and then left for at least overnight. The fabric treated in step (1) was then immersed in the mixed solution for 1 hour.

[0056] Comparative Example 2

[0057] (1) The fabric (cotton, polyester, viscose) was first cleaned with ethanol and deionized water by ultrasonic washing at least 3 times to remove possible contaminants and dried at 65°C. The fabric was then plasma treated for 20 minutes to remove possible oils, dust and other impurities present on the surface and to make the fabric surface rich in hydroxyl groups.

[0058] (2) The fabric (cotton, polyester, viscose) treated in step (1) was immersed in a solution of the polycationic electrolyte NaCl for 20 minutes. That is, it was immersed in a solution of PDADMAC (1.0 mg / mL) in 0.5 M NaCl in water for 20 minutes, then rinsed thoroughly with water for 10 minutes and dried in vacuum for 10 minutes. Subsequently, the fabric coated with PDADMAC was immersed in a solution of the polyanionic electrolyte NaCl for 20 minutes. That is, it was immersed in a solution of PSS (1.0 mg / mL) in 0.5 M NaCl in water for 20 minutes, then rinsed thoroughly with water for 10 minutes and dried in vacuum for 10 minutes. The film at this point was called PDADMAC / PSS 1 and the deposition cycle was repeated to produce PDADMAC / PSS 3.5 polyelectrolyte multilayers.

[0059] The PDADMAC / PSS 3.5 fabric was immersed in a solution of Na2SO4 (100 mM) in water for 1 hour, then rinsed thoroughly with water and dried in vacuum for 10 minutes. The resulting PDADMAC / PSS 3.5 with SO4 -2 ions as surface counterions.

[0060] The resulting PDADMAC / PSS 3.5The coated fabric was immersed in a NaCl solution of polyanion electrolyte for 20 minutes. That is, it was immersed in a PVS (1.0 mg / mL) aqueous solution of 0.5M NaCl for 20 minutes, then washed thoroughly with water for 10 minutes, and dried in a vacuum for 10 minutes. This deposition cycle was repeated three times to produce a PDADMAC / PSS 3.5 PVS3 polyelectrolyte multilayer.

[0061] The super-hydrophilic self-cleaning coated fabric prepared in Example 1 was taken for material apparent morphology observation, water contact angle test, sample durability, underwater oil-repellent performance, and self-cleaning efficiency evaluation, and the methods and results are as follows:

[0062] (1) Material structure and surface water contact angle;

[0063] Figure 1 The SEM images of the super-hydrophilic coated fabrics of polyester (a), viscose (b), and cotton (c) in Example 1. This method drives the positively charged polydimethyl diallyl ammonium chloride (PDADMAC) and the negatively charged sodium polystyrene sulfonate (PSS) to be alternately deposited through electrostatic interaction, and a PDADMAC / PSS 3.5 layered polyelectrolyte composite film (seven cycles refer to the deposition of 4 times of PDADMAC and 3 times of PSS, and 3.5 means 3.5 PDADMAC / PSS polyelectrolyte layers, which means that PDADMAC / PSS is regarded as a whole, so the subscript of PSS is 3.5), forming a cationic and anionic network structure with a molecular level interface combination. On this basis, polyvinyl sulfonic acid (PVS) is introduced for the third phase functional assembly, and a PDADMAC / PSS 3.5 PVS3 three-dimensional interpenetrating network structure. The coating can have a strong adsorption effect on the fabric, and, notably, the PVS anions form a continuous phase structure in the composite structure through a topological penetration mode. This multi-scale synergistic enhancement mechanism enables the coating system to exhibit excellent crack inhibition capability when subjected to physical damage caused by mechanical stress, and still maintains structural integrity in an acid / alkali chemical corrosion environment, exhibiting significantly enhanced environmental tolerance.

[0064] The super-hydrophilic property of the coating surface benefits from the high-density ordered arrangement of sulfonic acid groups in the surface modification layer and their symmetrical distribution at the molecular level, which significantly improves the surface energy of the modified fabric, and the water contact angle tends to 0°, exhibiting typical super-hydrophilic interface behavior. This functionalization strategy is universal for different textile substrates. Figure 2 The shape change of a water droplet on the polyester coated fabric is shown. From Figure 2 It can be seen that the textile coating prepared by the present application has good hydrophilicity.

[0065] (2) Underwater oil-repellent performance and self-cleaning performance;

[0066] Polyelectrolyte multilayer film PDADMAC / PSS 3.5 The surface of PVS3 has strong self-cleaning function of nanoscale smooth surface because it contains sulfonate groups with strong hydration ability and the adjacent nonpolar groups between the sulfonate groups are small methylene groups (isotropic arrangement of molecular configuration), but the sulfonate groups are separated from each other by the hydrophobic benzene ring, and the overall molecular configuration is anisotropic, so the polyelectrolyte multilayer film surface has certain oil adhesion. Therefore, the present scheme is optimized from two dimensions of interface charge regulation and surface structure design. First, positively charged inorganic silica ions are introduced, and second, hydrophilic sulfonate ions are combined with silica nanoparticles through an organic-inorganic composite strategy: the sulfonic groups in the organic material can enhance the interface hydration, and the nanoparticles form a micro-nano hierarchical structure on the surface through controllable accumulation. According to the surface wetting theory, this synergistic design can simultaneously meet two key conditions: the hydrophilic chemical component provides hydrophilic groups to reduce the contact angle, and the micro-nano rough structure enhances the apparent presentation of hydrophilicity through capillary effect, so as to finally realize the efficient stripping of oily pollutants under the action of dynamic water flow. Compared with single-component modification, the composite system significantly improves the anti-adhesion ability and self-cleaning efficiency of the surface to oily pollutants while maintaining the inherent properties of the polyelectrolyte multilayer film.

[0067] The underwater super-oil-repellent properties and self-cleaning performance of the coated fabric are verified by a systematic test method. As shown in Figure 3 , first, the material is characterized by a two-parameter detection method: by precisely measuring the sliding track of the underwater oil droplets on the inclined coated surface, combined with quantitative analysis of the oil contact angle (OCA), it is confirmed that the coated fabric has significant underwater super-oil-repellent properties. In terms of self-cleaning performance evaluation, a dynamic water flow washing method is used to simulate the actual cleaning environment, and by comparing the differences between the oil-polluted samples before and after treatment, the self-cleaning efficiency of the coating is evaluated, and the related experimental results are shown in Figure 4 . This series of tests form a complete evaluation chain from surface property characterization to functional performance verification, effectively demonstrating the functional properties of the coating.

[0068] (3) Self-cleaning performance test

[0069] Principle analysis of self-cleaning efficiency test:

[0070] Test of physical properties: i.e. test of whiteness, using a DSDB-1 digital whiteness meter, first calibrate with a standard white board of 81.8%, then measure the coated fabric and original fabric samples at different positions while keeping the warp and weft directions consistent for 3 times, and the result is the average of 3 times.

[0071] Whiteness retention: reflects the anti-redeposition performance (washed stains cannot contaminate the washed fabric) is determined according to formula (1); wherein the parameters are the whiteness values (%) of the original (R0) and the dirty cloth before (R1) and after (R2) washing, which are measured using a whiteness colorimeter.

[0072]

[0073] By measuring the whiteness retention of the coated fabric (formula 1), it is found that the whiteness retention of the SiO2-polyelectrolyte coated fabric group can reach 90%, which is about 10% higher than that of the polyelectrolyte coated fabric group (comparative example 2), and far exceeds that of the SiO2 coated fabric group (comparative example 1) and the blank fabric group. As shown in Figure 5 , this result shows that in the case of using SiO2-polyelectrolyte coating, cleaning without using detergent can achieve the traditional detergent-based cleaning performance of stains.

[0074] (4) Durability test of coated fabric - washing resistance test;

[0075] The durability of the coating material is particularly important, and the experiment focuses on the application characteristics of the fabric substrate to build a coating durability evaluation system. Referring to GB / T12490-2014 "Textile Color Fastness Test - Color Fastness to Home and Commercial Washing", washing is carried out in a washing color fastness tester. Prepare 0.2% concentration of non-phosphorus ECE standard detergent, cut the finished cotton, polyester and viscose fabric into 10cm*10cm, put them into a special washing cup containing 150mL of detergent and 10 steel balls, wash at 40℃ for 45min, and rinse the washed sample with deionized water twice. The above procedure is equivalent to 5 times of conventional washing, and the performance data is obtained through a step-by-step increasing washing experiment (10, 20, 30 cycles), and the decay curve of the coating performance retention rate with the increase of washing times is constructed based on the whiteness retention rate. As shown in Figure 6 , the experimental results show that after 30 times of standard washing procedure, the whiteness retention rate of the coated fabric can still maintain more than 60%, which fully proves that the coated fabric has excellent washing resistance stability.

[0076] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the present application. Of course, the above description is not a limitation of the present application, and the present application is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present application should also be within the scope of the present application.

Claims

1. A method for preparing a self-cleaning textile coating with underwater easy decontamination function, characterized in that The following steps are involved: a. Constructing a super-hydrophilic inorganic layer on the fabric; a1. Select fabric and perform pre-treatment; a2. Mixing ammonium hydroxide and ethanol, then adding tetraethyl orthosilicate to react to obtain a reaction solution; a3, soaking the fabric pre-treated in step a1 in the reaction solution obtained in step a2; b. constructing a polyelectrolyte layer; b1. Soaking the fabric treated in step a in a NaCl solution of a polycationic electrolyte, rinsing with water, and drying; then soaking the fabric in a NaCl solution of a first polyanion electrolyte, rinsing with water, and drying; b2. Soak the fabric treated in step b1 in a Na2SO4 aqueous solution, rinse with water after soaking, and dry; then soak in a NaCl solution of a second polyanion electrolyte, rinse with water after soaking, and dry to complete the construction of the polyelectrolyte layer on the fabric, and obtain a self-cleaning textile coating with underwater easy decontamination function.

2. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step a1, the pretreatment process is as follows: the fabric is ultrasonically cleaned multiple times with ethanol and deionized water in sequence, and then dried, and then the fabric is plasma treated, and the plasma treatment time is controlled to be 20-30 minutes.

3. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step a2: the reaction process is carried out at room temperature, ultrasonic treatment is performed during the reaction process, and the reaction time is maintained at 2-3 hours.

4. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step a3: the reaction solution obtained in step a2 is allowed to stand for 12-24 hours, and then the fabric pre-treated in step a1 is immersed in the reaction solution, and the immersion time is controlled to be 1-2 hours.

5. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step b1: the polycationic electrolyte NaCl solution comprises polydimethyldiallyl ammonium chloride; the concentration of polydimethyldiallyl ammonium chloride in the polycationic electrolyte NaCl solution is 1.0-1.5 mg / mL, and the concentration of NaCl is 0.4-0.5 M; the immersion time is controlled to be 20-30 minutes, the water rinsing time is 10-15 minutes, and the drying is performed in a vacuum for 10-15 minutes.

6. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step b1: in the NaCl solution of the first polyanion electrolyte, the first polyanion electrolyte is sodium polystyrene sulfonate; in the NaCl solution of the first polyanion electrolyte, the concentration of sodium polystyrene sulfonate is 0.8-1.2 mg / mL, and the concentration of NaCl is 0.4-0.6 M; the immersion time is controlled to be 10-30 minutes, the water rinsing time is 10-15 minutes, and the drying is carried out in a vacuum for 10-15 minutes.

7. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step b2: the concentration of the Na2SO4 aqueous solution is 100-120 mM, and the fabric is controlled to be immersed in the Na2SO4 aqueous solution for 1-1.5 hours; after soaking and rinsing, the fabric is controlled to be dried in a vacuum for 10-15 minutes.

8. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step b2: in the NaCl solution of the second polyanion electrolyte, the second polyanion electrolyte is sodium polyethylene sulfonate; in the NaCl solution of the second polyanion electrolyte, the concentration of sodium polyethylene sulfonate is 0.5-1.0 mg / mL, and the concentration of NaCl is 0.4-0.6 M; the immersion time is controlled to be 10-30 minutes, the water rinsing time is 10-15 minutes, and the drying is carried out in a vacuum for 10-15 minutes.

9. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: In step b: the fabric is controlled to be repeatedly immersed in a NaCl solution of a polycationic electrolyte and a NaCl solution of a first polyanion electrolyte, rinsed with water, and dried multiple times to perform a deposition cycle of the polycationic electrolyte and the first polyanion electrolyte; the fabric is controlled to be repeatedly immersed in a NaCl solution of a second polyanion electrolyte, rinsed with water, and dried multiple times to perform a deposition cycle of the second polyanion electrolyte, thereby achieving the construction of a multilayer polyelectrolyte on the fabric surface.

10. The method for preparing a self-cleaning textile coating with underwater easy decontamination function according to claim 1, characterized in that: The self-cleaning textile coating obtained by this method can achieve underwater self-cleaning performance, and the self-cleaning efficiency reaches 88.97% to 92.68% after washing with clean water.

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