Preparation method of improved super-hydrophobic antibacterial fabric with photothermal effect

Abstract

The invention discloses an improved super-hydrophobic antibacterial fabric with illumination heat production and metal sterilization and a preparation method thereof.The preparation method comprises the steps that nano particles with photo-thermal and sterilization effects are prepared and attached to a fabric base body through an impregnation method, then a silane coupling agent of an alkane chain is used for modifying the surface of a material, and the modified nano particles are prepared into the super-hydrophobic antibacterial fabric with the illumination heat production and metal sterilization functions. The super-hydrophobic material with excellent photo-thermal and active antibacterial properties is prepared by introducing a substance for reducing surface energy and constructing high roughness; the surface water contact angle of the prepared super-hydrophobic antibacterial fabric is 152.4 degrees, the surface temperatures are respectively increased to 54.7 DEG C and 105 DEG C under the irradiation of sunlight and near-infrared light, and the super-hydrophobic antibacterial fabric shows excellent photo-thermal cycling stability and super-hydrophobic high temperature resistance; the super-hydrophobic antibacterial fabric has a good antibacterial effect on staphylococcus aureus and escherichia coli, and the bacteriostasis rate of the super-hydrophobic antibacterial fabric on the staphylococcus aureus and the escherichia coli can reach 100% under the condition of near-infrared light. The antibacterial efficiency is high; the antibacterial range is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of superhydrophobic antibacterial fabrics, and particularly to a preparation method of an improved superhydrophobic antibacterial fabric with a photothermal effect. Background Art

[0002] To solve the defects existing in the technical solutions disclosed in CN116219763B and CN115928441B, and aiming at the problems existing in the prior art such as the lack of bactericidal property in passive superhydrophobic sterilization and the inability to maintain a 100% sterile surface condition for a long time, and the limited antibacterial life of active antibacterial materials, the applicant combines the special wettability of superhydrophobic materials with the excellent bactericidal performance of antibacterial materials to develop a superhydrophobic antibacterial fabric with a photothermal effect that can maintain a high antibacterial efficiency for a long time and has high safety, as shown in the invention patent application with the patent application number 202510047210.4 applied by the applicant. However, on this basis, the applicant further conducts research and development to obtain a superhydrophobic antibacterial fabric with better comprehensive performance, including better high-temperature performance, longer maintenance of high antibacterial efficiency time, and higher safety. Summary of the Invention

[0003] The purpose of the present invention is to develop a preparation method of an antibacterial superhydrophobic coating with active bactericidal activity, which has a simple process. The superhydrophobic antibacterial fabric not only has excellent photothermal cycle stability and superhydrophobic high-temperature resistance performance, but also can maintain a high antibacterial effect for a long time and has high safety.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is: a preparation method of an improved superhydrophobic antibacterial fabric with a photothermal effect, including the following steps,

[0005] Step S1: After cleaning the chemical fiber fabric, soak it in the aqueous dispersion of the photothermal preparation, then take it out and perform a drying treatment. Repeat the soaking treatment and the drying treatment multiple times to obtain a photothermal fabric with the photothermal preparation attached to its surface;

[0006] Step S2: By volume fraction, add 2 - 3 parts of ammonia water to 98 parts of ethanol and mix evenly. Then take another 100 parts of ethanol, add 0.5 - 4 g of a fluorine-containing silane coupling agent and 0.5 - 4 g of a silicate compound to the ethanol respectively and mix to obtain a mixed solution. Stir and mix the mixed solution at a temperature of 25 - 60 °C for 2 - 8 h to obtain a superhydrophobic modified dispersion;

[0007] Step S3: Put the optothermal fabric processed in Step S1 into the superhydrophobic modification dispersion prepared in Step S2. After stirring at 60 - 80°C for 0.5 - 3 h, take out the optothermal fabric and put it into an oven at 80 - 120°C for crosslinking and curing for 0.5 - 2 h to obtain a superhydrophobic antibacterial fabric with optothermal effect.

[0008] A fluoroalkane coupling agent / hydrophobic silica nanoparticle crosslinked composite coating is attached to the surface of the fabric substrate of the superhydrophobic antibacterial fabric.

[0009] In Step S3, the fluoroalkane coupling agent / hydrophobic silica nanoparticle crosslinked composite coating is formed by partial self-condensation and polymerization of hydrolyzed silicate esters at a high temperature of 80 - 120°C to generate hydrophobic silica nanoparticles. The fluoroalkane coupling agent is a silane coupling agent containing a fluoroalkyl group, which has a low surface energy and good chemical stability. At a high temperature of 80 - 120°C, the fluoroalkane coupling agent can undergo a condensation reaction with the carboxyl or hydroxyl groups of the optothermal agent, and can also bind to the hydroxyl groups between fibers through electrostatic or hydrogen bond interactions. This synergistic effect of chemical bonding and physical forces enables good adhesion between the fluoroalkane coupling agent / hydrophobic silica nanoparticle composite coating, the fabric substrate of the superhydrophobic antibacterial fabric, and the optothermal agent layer.

[0010] In Step S1, put the chemical fiber fabric into an ethanol solution and perform ultrasonic cleaning for 2 - 5 min. After ultrasonic cleaning, take it out and place it in an oven at 60 - 100°C for drying. Subsequently, use vacuum plasma to perform surface cleaning on the front and back of the chemical fiber fabric once each, with the surface cleaning time being 60 - 90 s. After completing the surface cleaning, place the chemical fiber fabric in an aqueous dispersion of the optothermal agent with a volume concentration of 2 - 8 mg / mL for soaking for 2 - 5 min, then take it out and place it in an oven at 60 - 100°C for drying. Repeat the soaking and drying processes 2 - 5 times to obtain the optothermal fabric with the optothermal agent attached to its surface.

[0011] In Step S1, the aqueous dispersion of the optothermal agent is a uniformly dispersed solution obtained by putting the optothermal agent into water and performing ultrasonic dispersion treatment. The optothermal agent is selected as dopamine.

[0012] During the treatment of the optothermal agent, the hydrogen bond and / or electrostatic interactions formed between the hydroxyl and carboxyl groups in the molecule of the optothermal agent and the fibers of the chemical fiber fabric make the surface of the fibers of the chemical fiber fabric rough, which is used to enhance the physical adhesion between the optothermal agent and the fiber surface, improve the surface characteristics of the chemical fiber fabric, and endow the chemical fiber fabric with excellent optothermal performance.

[0013] In step S1, the material of the fabric is one of polyester, nylon, spandex, and cellulose; the type of the fabric is melt-blown fabric, non-woven fabric, or woven fabric.

[0014] In step S2, the fluorine atom-containing silane coupling agent and the silicate ester undergo a hydrolysis reaction in ethanol under the promotion of the ammonia water and the water, and the obtained hydrolysis reactant reacts with the silicate ester to generate hydrophobic silica nanoparticles with good compatibility. After the ultrasonic treatment, the hydrolysis reactant and the hydrophobic silica nanoparticles are uniformly dispersed in the solution to maintain the stable modified dispersion liquid.

[0015] In step S2, the fluorine atom-containing silane coupling agent is selected from at least one of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane, tridecafluorooctyltrimethoxysilane, and perfluorodecyltrimethoxysilane.

[0016] In step S2, the mass concentration of the fluorine atom-containing silane coupling agent in the solvent composed of ethanol, ammonia water, and water is 0.005 - 0.04 mg / mL.

[0017] In step S2, the hydrophobic silica nanoparticles are generated by hydrolysis of a silicate compound. The particle size of the hydrophobic silica nanoparticles is 0.5 - 0.8 μm; the mass ratio of the silicate compound to the fluorine atom-containing silane coupling agent is 1:1.

[0018] The silicate compound is selected from at least one of tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetraisopropyl orthosilicate.

[0019] An improved superhydrophobic antibacterial fabric with a photothermal effect is prepared according to the above preparation method of an improved superhydrophobic antibacterial fabric with a photothermal effect. A cross-linked composite coating of a fluoroalkyl coupling agent and hydrophobic silica nanoparticles is attached to the surface of the fabric substrate of the superhydrophobic antibacterial fabric. The superhydrophobic antibacterial fabric with a photothermal effect combines passive superhydrophobic antibacterial adhesion and active photothermal sterilization in antibacterial applications. Under near-infrared light conditions, the antibacterial rates against Staphylococcus aureus and Escherichia coli can reach 100%. It has strong antibacterial performance and a wide antibacterial range.

[0020] The advantages of the present invention compared with the prior art are as follows: The present invention loads the photothermal preparation on the surface of the chemical fiber fabric through repeated impregnation-drying, and then coats a mixed solution of silicate esters and a fluorine atom-containing silane coupling agent on the fabric under alkaline conditions. After thermal crosslinking, a superhydrophobic antibacterial fabric with a photothermal effect is prepared. The photothermal preparation and the nano-silica generated by the hydrolysis of silicate esters synergistically construct a uniform micro-nano rough structure on the fabric surface. After hydrolysis under alkaline conditions, the fluorine atom-containing silane coupling agent undergoes a condensation reaction with the carboxyl and hydroxyl groups of the photothermal preparation and grafts onto the surface of the photothermal preparation layer. Due to the characteristics of fluorine atoms themselves, the fabric is synergistically given a low surface energy. The combination of the rough morphology and the special chemical structure enables the fabric surface to achieve superhydrophobicity. The introduction of the photothermal preparation significantly improves the photothermal conversion performance of the fabric. With the synergistic effect of passive antibacterial adhesion on the superhydrophobic surface and the active bactericidal effect of the photothermal preparation, the fabric exhibits excellent antibacterial efficiency against a variety of bacteria. In addition, the self-cleaning effect of the superhydrophobic surface can effectively remove the attached dead bacteria and reduce their adhesion on the surface of the antibacterial material, thus significantly prolonging the service life of the antibacterial material. The preparation process adopted by the present invention is simple, efficient and low-cost. The prepared photothermal superhydrophobic antibacterial fabric not only has excellent stability and a wide antibacterial range, but also has high safety and no drug resistance problem.

[0021] The preparation process of the present invention is more simple and efficient, and has good scalability, suitable for large-scale industrial production, effectively reducing the comprehensive production cost. The prepared superhydrophobic antibacterial fabric exhibits excellent photothermal cycle stability and superhydrophobic high-temperature resistance, and can maintain an efficient antibacterial effect for a long time, while having high safety. In addition, the raw materials used in the present invention have low costs, and the superhydrophobic antibacterial fabric has advantages such as low energy consumption and environmental friendliness, and has significant application value and broad application prospects in the field of medical protective materials.

[0022] The present invention constructs a fabric with excellent superhydrophobicity through the binary synergistic effect of the micro-nano rough structure synergistically constructed by the photothermal preparation and the nano-silica generated by the hydrolysis of silicate esters on the fabric surface and the low-surface-energy fluoroalkane-chain silane coupling agent. The obtained micro-nano rough structure is smaller and the surface is denser than the micro-nano rough structure of the technical solution described in the prior application No. 202510047210.4; at the same time, a chemical crosslinking structure is formed by the dehydration condensation reaction between the photothermal preparation and the silane coupling agent. In addition, by introducing a photothermal preparation layer, the fabric has excellent heat generation performance under sunlight or near-infrared light irradiation, and the surface temperature can reach 105°C. Due to its structural stability, the superhydrophobic antibacterial fabric of the present invention can maintain the superhydrophobic performance for a long time under the high-temperature condition of 105°C, significantly enhancing the heat resistance stability and antibacterial persistence of the fabric, that is, it still has a longer and more effective antibacterial performance at a relatively lower temperature and higher safety.

[0023] The present invention first loads a photothermal agent on the surface of the fabric to endow it with photothermal properties, and then introduces a composite coating formed by silicate esters and fluoroalkane chain silane coupling agents to reduce the surface energy of the material and construct a micro-nano rough structure, thereby preparing a superhydrophobic antibacterial fabric with excellent photothermal and superhydrophobic properties. The water contact angle of the surface of the superhydrophobic antibacterial fabric prepared by the present invention is 152.4°, and the surface temperature reaches 105°C under near-infrared light irradiation, showing excellent photothermal cycle stability and superhydrophobic high-temperature resistance. It has a good antibacterial effect on Staphylococcus aureus and Escherichia coli. Under near-infrared light conditions, the antibacterial rate against Staphylococcus aureus and Escherichia coli can reach 100%, demonstrating excellent antibacterial and bacteriostatic properties.

[0024] The superhydrophobic antibacterial fabric of the present invention is prepared by the above preparation method, realizing the synergistic integration application of superhydrophobic antibacterial and photothermal sterilization, and showing excellent antibacterial performance. On the one hand, the superhydrophobic property of the fabric significantly reduces the attachment probability of bacteria on the material surface; on the other hand, the photothermal agent layer can quickly kill a small amount of bacteria attached to the material surface under light irradiation, thus realizing a dual protection mechanism. This fabric not only has high antibacterial efficiency and a wide antibacterial range, but also has a long antibacterial lifespan, and is safe and reliable without drug resistance problems. In antibacterial applications, the photothermal superhydrophobic fabric combines passive superhydrophobic antibacterial with active photothermal sterilization, with strong antibacterial effects and long-lasting continuous effects. Description of the Drawings

[0025] Figure 1 Scanning electron microscope images of the superhydrophobic antibacterial fabric with photothermal effect prepared in Example 1. Figure a has a magnification of 600 times, and Figure b has a magnification of 5000 times.

[0026] Figure 2 X-ray energy spectrum analysis of the superhydrophobic antibacterial fabric with photothermal effect prepared in Example 1.

[0027] Figure 3 Photothermal conversion ability of the superhydrophobic antibacterial fabric with photothermal effect prepared in Example 1 under near-infrared light with different light intensities.

[0028] Figure 4 Resistance effects against Escherichia coli and Staphylococcus aureus of the original fabric and the superhydrophobic antibacterial fabric with photothermal effect prepared in Example 1 before and after near-infrared light irradiation. Detailed Description of the Invention

[0029] Example 1

[0030] A preparation method of an improved superhydrophobic antibacterial fabric with photothermal effect

[0031] First, place the chemical fiber fabric into a vacuum plasma processor for plasma cleaning. The cleaning time is 60 s, and both the front and back sides are cleaned once. Then soak it in a 3.8 mg / mL PDA@ZIF solution for 2 minutes, take it out and dry it in an oven at 50 °C, and repeat the soaking-drying process 5 times. Subsequently, add a mixed solution of 1 g of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane, 1 g of tetraethyl orthosilicate, and 50 mL of ethanol to 49 mL of ethanol and 1 mL of ammonia water, and heat and stir at 60 °C for 3 h to obtain a superhydrophobic modification solution. Finally, place the fabric loaded with PDA@ZIF particles (polydopamine-coated zeolitic imidazolate framework solution) into the modification solution, stir at 60 °C for 1 h, take it out and place it in an oven at 100 °C for cross-linking reaction for 1 h to prepare a superhydrophobic antibacterial fabric with a photothermal effect.

[0032] Figure 1 SEM image of the photothermal superhydrophobic antibacterial fabric prepared in Example 1. It can be seen that a cross-linked coating (FAS-SiO2 coating) of a low surface energy fluorine-containing substance and silica particles is clearly coated on the basis of the antibacterial fabric. The silica particles are generated by the hydrolysis of tetraethyl orthosilicate, and their particle size is between 0.5 - 0.8 μm. Not only is a low surface energy fluorine-containing substance successfully grafted, but also the surface roughness of the fabric is further increased, endowing the fabric with superhydrophobic properties, and the surface contact angle is 152.4°. In addition, due to the stable cross-linked structure formed between trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane and PDA@ZIF, the fabric has good thermal stability, and it still maintains superhydrophobicity after being treated in an environment of 120 °C for 72 h, and the contact angle is 151.5°.

[0033] Figure 2 X-ray energy spectrum analysis of the photothermal superhydrophobic antibacterial fabric prepared in Example 1. Through elemental surface scanning and EDS analysis, it can be seen that in addition to carbon, oxygen, nitrogen, and zinc elements on the surface of the prepared photothermal superhydrophobic antibacterial fabric, it also contains silicon and fluorine elements, and the distribution of each element on the fiber surface is uniform, as Figure 2 shown, which indicates that the superhydrophobic modification of the PDA@ZIF fabric is successful. The atomic percentage contents of C, O, F, Si, N, and Zn elements on the surface of the F-PDA@ZIF fabric are 58.8%, 22.1%, 11.7%, 4.9%, 1.9%, and 0.5% respectively

[0034] Figure 3 Photothermal conversion ability of the superhydrophobic antibacterial fabric with a photothermal effect prepared in Example 1 under near-infrared light with different light intensities. At 0.25 W / cm 2 、0.50 W / cm 2 and 0.75 W / cm 2Under the irradiation of near-infrared light with a power of, the surface temperatures of the fabric reached 48.1 °C, 74.6 °C, and 96.9 °C at the 10th second respectively; they tended to be stable at the 1st minute, and the temperatures reached 58.2 °C, 98.7 °C, and 129 °C respectively at this time; the temperatures reached 62.6 °C, 105 °C, and 139 °C at the 4th minute. Under the near-infrared light with a power of 0.50 W / cm 2 The temperature can be stably maintained above 100 °C. Research shows that at a temperature of 100 °C, most bacteria, such as Escherichia coli and Staphylococcus aureus, are difficult to survive, thus achieving a good antibacterial effect.

[0035] Figure 4 The resistance effects of the photothermal superhydrophobic antibacterial fabric prepared in Example 1 against Escherichia coli and Staphylococcus aureus before and after near-infrared light irradiation are shown. It can be seen that the bacterial colonies cultured on the basis of the original fabric are very densely distributed on the agar plate; due to the special wettability of the photothermal superhydrophobic antibacterial fabric prepared in this example, bacteria are difficult to attach to the sample surface, resulting in a significant reduction in the bacterial content on the agar plate of this experimental group. However, due to the inevitable reduction of the rough structure on the surface of the superhydrophobic antibacterial fabric during storage, there are still some colonies on the fabric surface; in addition, irradiating the photothermal superhydrophobic antibacterial fabric with near-infrared light with a power of 0.5 W / cm 2 for 5 minutes, PDA can rapidly heat up under near-infrared light, which can promote the release of zinc ions, and at the same time, the high temperature can also sterilize synchronously to achieve a stronger antibacterial effect. Therefore, no colonies grow on the agar plate, and the antibacterial rate against Escherichia coli and Staphylococcus aureus is as high as 100%.

[0036] The test results of the hydrophobic property, high-temperature stability property, and photothermal conversion property of the fabric are shown in Table 1, and the test results of the antibacterial property of the fabric are shown in Table 2.

[0037] Example 2

[0038] A preparation method of an improved superhydrophobic antibacterial fabric with a photothermal effect,

[0039] First, place the polyurethane non-woven fabric into a vacuum plasma processor for plasma cleaning. The cleaning time is 60 s, and each side (front and back) is cleaned once. Then soak it in a 2 mg / mL PDA@ZIF solution for 2 minutes, take it out and dry it in an oven at 50 °C. Repeat the soaking-drying process 5 times. Subsequently, add a mixed solution of 0.5 g of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane, 0.5 g of tetraethyl orthosilicate, and 50 mL of ethanol to 49 mL of ethanol and 1 mL of ammonia water, and heat and stir at 60 °C for 3 h to obtain a superhydrophobic modification solution. Finally, place the fabric loaded with PDA@ZIF particles into the modification solution, stir at 60 °C for 1 h, take it out and place it in an oven at 100 °C for cross-linking reaction for 1 h to prepare a superhydrophobic antibacterial fabric with a photothermal effect.

[0040] The test results of the hydrophobic property, high-temperature stability, and photothermal conversion property of the fabric are shown in Table 1, and the test results of the antibacterial property of the fabric are shown in Table 2.

[0041] Example 3

[0042] A preparation method of an improved superhydrophobic antibacterial fabric with a photothermal effect,

[0043] First, place the polypropylene melt-blown fabric into a vacuum plasma processor for plasma cleaning. The cleaning time is 60 s, and each side (front and back) is cleaned once. Then soak it in an 8 mg / mL PDA@ZIF solution for 2 minutes, take it out and dry it in an oven at 50 °C. Repeat the soaking-drying process 5 times. Subsequently, add a mixed solution of 4 g of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane, 4 g of tetraethyl orthosilicate, and 50 mL of ethanol to 49 mL of ethanol and 1 mL of ammonia water, and heat and stir at 60 °C for 3 h to obtain a superhydrophobic modification solution. Finally, place the fabric loaded with PDA@ZIF particles into the modification solution, stir at 60 °C for 1 h, take it out and place it in an oven at 100 °C for cross-linking reaction for 1 h to prepare a superhydrophobic antibacterial fabric with a photothermal effect.

[0044] The test results of the hydrophobic property, high-temperature stability, and photothermal conversion property of the fabric are shown in Table 1, and the test results of the antibacterial property of the fabric are shown in Table 2.

[0045] Example 4

[0046] A preparation method of an improved superhydrophobic antibacterial fabric with a photothermal effect,

[0047] First, place the polyester fabric into a vacuum plasma processor for plasma cleaning. The cleaning time is 60 s, and each side (front and back) is cleaned once. Then immerse it in a 6 mg / mL PDA@ZIF solution for 2 minutes, take it out and dry it in an oven at 50 °C. Repeat the immersion-drying process 5 times. Subsequently, add a mixed solution of 3 g of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane, 3 g of tetraethyl orthosilicate and 50 mL of ethanol to 49 mL of ethanol and 1 mL of ammonia water, and heat and stir at 60 °C for 3 h to obtain a superhydrophobic modification solution. Finally, place the fabric loaded with PDA@ZIF particles into the modification solution, stir at 60 °C for 1 h, take it out and place it in an oven at 100 °C for cross-linking reaction for 1 h to prepare a superhydrophobic antibacterial fabric with a photothermal effect.

[0048] The test results of the hydrophobic property, high-temperature stability property and photothermal conversion property of the fabric are shown in Table 1, and the test results of the antibacterial property of the fabric are shown in Table 2.

[0049] Comparative Example 1

[0050] In order to verify the key role of the rough structure in the photothermal superhydrophobic antibacterial fabric prepared by the present invention in achieving the superhydrophobic property, and to explore the important significance of the superhydrophobic surface in improving the antibacterial efficiency, in this study, a fabric without adding silicate esters was used as a control group for comparative experiments.

[0051] First, place the chemical fabric into a vacuum plasma processor for plasma cleaning. The cleaning time is 60 s, and each side (front and back) is cleaned once. Then immerse it in a 3.8 mg / mL PDA@ZIF solution for 2 minutes, take it out and dry it in an oven at 50 °C. Repeat the immersion-drying process 5 times. Subsequently, add a mixed solution of 1 g of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane and 50 mL of ethanol to 49 mL of ethanol and 1 mL of ammonia water, and heat and stir at 60 °C for 3 h to obtain a superhydrophobic modification solution. Finally, place the fabric loaded with PDA@ZIF particles into the modification solution, stir at 60 °C for 1 h, take it out and place it in an oven at 100 °C for cross-linking reaction for 1 h to prepare a superhydrophobic antibacterial fabric with a photothermal effect.

[0052] The test results of the hydrophobic property and photothermal conversion property of the fabric are shown in Table 1, and the test results of the antibacterial property of the fabric are shown in Table 2.

[0053] Comparative Example 2

[0054] In order to verify the key role of the surface energy and rough structure in the photothermal superhydrophobic antibacterial fabric prepared by the present invention in achieving the superhydrophobic property, and to explore its influence on the fabric morphology, in this study, fabrics adding ordinary silane coupling agents and directly adding hydrophobic silica nanoparticles were used as control groups for comparative experiments.

[0055] First, place the chemical fiber fabric into a vacuum plasma processor for plasma cleaning. The cleaning time is 60 s, and each side (front and back) is cleaned once. Then immerse it in a 3.8 mg / mL PDA@ZIF solution for 2 minutes, take it out and dry it in an oven at 50 °C, and repeat the immersion-drying process 5 times. Subsequently, add 1 g of cetyltrimethoxysilane, 1 g of hydrophobic nano-silica with a particle size distribution of 0.5 - 0.8 μm, and a mixed solution of 50 mL of ethanol to 49 mL of ethanol and 1 mL of ammonia water, and heat and stir at 60 °C for 3 h to obtain a superhydrophobic modification solution. Finally, place the fabric loaded with PDA@ZIF particles into the modification solution, stir at 60 °C for 1 h, take it out and place it in an oven at 100 °C for cross-linking reaction for 1 h to prepare a superhydrophobic antibacterial fabric with a photothermal effect.

[0056] Performance Testing

[0057] (1) Scanning Electron Microscope Testing

[0058] Morphology observation was carried out using a scanning electron microscope (Zeiss sigma300, Germany), and the acceleration voltage was set at 10 kV. Before testing, the chemical fiber fabric was fixed on the specimen stage with conductive glue and sputter-coated with gold.

[0059] (2) Contact Angle Testing

[0060] The water droplet contact angle on the coating surface was measured using a contact angle meter (SDC-200S, Dongguan Shengding Precision Instrument Co., Ltd.). The size of the water droplet was 5 μL, and the contact angle value was calculated as the average of 5 positions on the fabric surface.

[0061] (3) X-ray Photoelectron Spectroscopy Testing

[0062] The surface elements of the antibacterial fabric and the superhydrophobic antibacterial fabric were analyzed using an X-ray photoelectron spectrometer (Escalab 250Xi, Thermo Fisher Scientific, USA). The laser source used during testing was Al-Kα X-ray (hv = 1486.6 eV), the testing power was 300 W, the testing voltage was 15 kV, and the analysis area was 0.6 mm2.

[0063] (4) Photothermal Performance Testing

[0064] To evaluate the photothermal conversion performance of the fabric, irradiate the fabric with 808 nm near-infrared light with a power of 0.75 W / cm 2 and use an infrared thermal imager to detect and record the surface temperature of the fabric after 4 minutes of irradiation.

[0065] (5) Superhydrophobic Heat Resistance Stability Testing

[0066] To evaluate the heat-resistant stability of the fabric, the chemical fiber fabric was placed in an oven at 120 °C and heated for 72 h, and then the superhydrophobic antibacterial fabric was taken out for contact angle measurement.

[0067] (6) Antibacterial test

[0068] To study the antibacterial effect test of the fabric, the original fabric, the prepared polydopamine fabric, the antibacterial fabric and the superhydrophobic antibacterial fabric were used for antibacterial test. Among them, the original fabric was used as the control group, and the polydopamine fabric, the antibacterial fabric, the superhydrophobic antibacterial fabric and the superhydrophobic antibacterial fabric treated by near-infrared light for photothermal treatment were used as four experimental groups. They were co-cultured with 1 mL of bacterial suspension with an initial concentration of 1×10 6 CFU / mL at 37 °C for 24 h. After that, the photothermal treatment group was treated under 808 nm near-infrared light with a power density of 0.5 W / cm 2 for 5 min. Then, the above-mentioned fabrics were ultrasonically treated for 5 min (40 kHz, 320 W). 20 μL was taken and spread on a sterile agar plate. After incubation at 37 °C for 18 h, the optical photos of the plate were recorded and the number of colonies was counted. The calculation formula of the antibacterial rate is: antibacterial rate (%) = [(number of colonies in the control group - number of colonies in the experimental group) / number of colonies in the control group] × 100%.

[0069]

[0070] Table 1 - Test results of hydrophobicity, high-temperature stability and photothermal conversion performance of fabrics

[0071]

[0072] Table 2 - Test results of antibacterial performance of fabrics

[0073] From the performance test results in Table 1 and Table 2, it can be found that the photothermal superhydrophobic antibacterial fabrics prepared in Examples 1 to 4 not only exhibit excellent superhydrophobic properties, but also can maintain their superhydrophobicity after being treated at high temperature for 72 hours, thus effectively improving the anti-bacterial adhesion ability of the material. At the same time, the photothermal conversion performance of the fabric is outstanding, and its combination with the superhydrophobic surface further enhances the antibacterial effect, making the antibacterial rate reach 100%.

[0074] In the performance test of Table 1, compared with Example 1, the fabric of Comparative Example 1 failed to exhibit superhydrophobicity. Although the fabric still had good photothermal conversion performance, and its surface temperature could rise to 114 °C due to the absence of silicate esters, the antibacterial rates against Escherichia coli and Staphylococcus aureus were significantly reduced. This was because the lack of silicate ester components in the coating resulted in the inability to form hydrophobic silica, making it difficult for the fibers to build sufficient roughness, and the contact angle of the fabric surface was only 140°. When bacteria came into contact with the fabric and multiplied on its surface, adhesion was likely to occur. Even if the surface bacteria were killed by simulated sunlight irradiation, the small amount of remaining inactivated bacteria would still affect the bactericidal effect, causing the antibacterial rates of the fabric under both light and dark conditions to decline.

[0075] In the performance test of Table 1, compared with Example 1, the surface smoothness of the fabric of Comparative Example 2 was significantly reduced. Comparative Example 2 used a silane coupling agent with an alkane chain. Its hydrophobic property was not as significant as that of fluorine atoms, and the formed structure was a undulating porous structure, increasing the roughness of the fabric surface. At the same time, the directly added silica particles could form a undulating porous structure with the silane coupling agent, increasing the roughness of the fabric surface. However, due to the relatively high surface roughness, the contact angle of 155° was slightly higher than that of Example 1. In contrast, the fabric of Example 1 not only had excellent superhydrophobic properties but also showed higher efficiency in photothermal conversion (surface temperature 105 °C). This indicated that the fabric surface of Example 1 was smoother, which could more effectively promote photothermal conversion while maintaining good superhydrophobic characteristics.

[0076] The photothermal effect superhydrophobic antibacterial fabric of the present invention is composed of a photothermal preparation layer, a low surface energy fluorosilane coupling agent, and hydrophobic nano-silica, and is realized through a chemical cross-linking structure. This fabric has excellent superhydrophobicity, heat resistance stability, photothermal conversion performance, and photothermal cycle stability. Its superhydrophobic property effectively reduces the adhesion of bacteria on the fabric surface. At the same time, the photothermal effect can quickly kill the attached bacteria, achieving the synergistic integration of superhydrophobic antibacterial and photothermal sterilization. In addition, this fabric also has significant advantages such as high antibacterial efficiency, broad antibacterial spectrum, long antibacterial lifespan, and being safe, reliable, and drug-resistant.

[0077] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and modifications can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect, characterized in that: The following steps are included: Step S1, after cleaning the chemical fiber fabric, immerse it in the aqueous dispersion of the photothermal agent, then take it out and dry it, repeat the immersion and drying processes for several times to obtain the photothermal fabric with the photothermal agent attached to the surface; Step S2, adding 2 to 3 parts of ammonia water to 98 parts of ethanol by volume and mixing evenly, taking another 100 parts of ethanol, adding 0.5 to 4 g of a silane coupling agent with a fluorine atom and 0.5 to 4 g of a silicate compound to the ethanol, respectively mixing to obtain a mixed solution, stirring the mixed solution at a temperature of 25 to 60° C. for 2 to 8 hours to obtain a super-hydrophobic modified dispersion; Step S3, placing the photothermal fabric treated in step S1 into the super-hydrophobic modified dispersion prepared in step S2, stirring at 60-80° C. for 0.5-3 h, then taking out the photothermal fabric and placing it in an oven at 80-120° C. for cross-linking and curing for 0.5-2 h to obtain a super-hydrophobic antibacterial fabric with photothermal effect, The surface of the fabric substrate of the super hydrophobic antibacterial fabric is attached with a fluorocarbon coupling agent / hydrophobic silica nanoparticle cross-linked composite coating.

2. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 1, characterized in that: In step S3, the fluorocarbon coupling agent / hydrophobic silica nanoparticle cross-linked composite coating is a hydrolyzed silicate ester that undergoes partial self-condensation and polymerization under high temperature conditions of 80 to 120°C to generate hydrophobic silica nanoparticles. The fluorocarbon coupling agent is a silane coupling agent containing a fluoroalkyl group, which has low surface energy and good chemical stability. Under high temperature conditions of 80 to 120°C, the fluorocarbon coupling agent can undergo condensation reaction with the carboxyl or hydroxyl group of the photothermal preparation, and can also combine with the hydroxyl group between fibers through electrostatic or hydrogen bonding. The synergistic effect of this chemical bonding and physical force allows the fluorocarbon coupling agent / hydrophobic silica nanoparticle composite coating, the fabric substrate of the super-hydrophobic antibacterial fabric, and the photothermal preparation layer to have good adhesion.

3. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 2, characterized in that: In the step S1, the chemical fiber fabric is placed in an ethanol solution and ultrasonically cleaned for 2 to 5 minutes. After ultrasonic cleaning, the chemical fiber fabric is taken out and placed in an oven at 60 to 100° C. for drying. Then, vacuum plasma is used to perform surface cleaning on the front and back sides of the chemical fiber fabric once respectively. The surface cleaning time is 60 to 90 seconds. After the surface cleaning is completed, the chemical fiber fabric is placed in a photothermal agent aqueous dispersion with a volume concentration of 2 to 8 mg / mL for immersion treatment for 2 to 5 minutes. Then, the chemical fiber fabric is taken out and placed in an oven at 60 to 100° C. for drying treatment. The immersion treatment and drying treatment are repeated 2 to 5 times to obtain the photothermal fabric with the photothermal agent attached to the surface.

4. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 3, characterized in that: In step S1, the photothermal agent aqueous dispersion is a uniformly dispersed solution obtained by putting the photothermal agent into water and performing ultrasonic dispersion treatment, and the photothermal agent is dopamine; During the photothermal preparation treatment process, the fiber surface of the chemical fiber fabric becomes rough through the hydrogen bonding and / or electrostatic effect formed between the hydroxyl and carboxyl groups in the molecules of the photothermal preparation and the fibers of the chemical fiber fabric, which is used to enhance the physical adhesion of the photothermal preparation to the fiber surface, improve the surface properties of the chemical fiber fabric and give the chemical fiber fabric excellent photothermal properties.

5. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 1, characterized in that: In the step S1, the material of the fabric is one of polyester, nylon, spandex, and cellulose; the type of the fabric is meltblown fabric, non-woven fabric or woven fabric.

6. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 1, characterized in that: In the step S2, the silane coupling agent with fluorine atoms and the silicate undergo a hydrolysis reaction in ethanol under the promotion of the ammonia water and the water, and the obtained hydrolysis reactant and the silicate generate hydrophobic silica nanoparticles with good compatibility. After the ultrasonic treatment, the hydrolysis reactant and the hydrophobic silica nanoparticles are uniformly dispersed in the solution and maintain the stable modified dispersion.

7. A method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to any one of claims 1 to 6, characterized in that: In the step S2, the silane coupling agent with fluorine atoms is selected from at least one of trimethoxy (1H, 1H, 2H, 2H-heptadecafluorodecyl) silane, tridecafluorooctyl trimethoxy silane and perfluorodecyl trimethoxy silane.

8. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 7, characterized in that: In the step S2, the mass concentration of the silane coupling agent with fluorine atoms in the solvent consisting of ethanol, ammonia water and water is 0.005-0.04 mg / mL.

9. The method for preparing an improved super-hydrophobic antibacterial fabric with photothermal effect according to claim 7, characterized in that: In step S2, the hydrophobic silica nanoparticles are generated by hydrolysis of silicate compounds, and the particle size of the hydrophobic silica nanoparticles is 0.5-0.8 μm; the mass ratio of the silicate compound to the silane coupling agent with fluorine atoms is 1:1; The silicate compound is selected from at least one of tetraethyl silicate, tetrapropyl silicate and tetraisopropyl silicate.

10. An improved super-hydrophobic antibacterial fabric with photothermal effect, characterized in that: The improved super-hydrophobic antibacterial fabric with photothermal effect is prepared by the preparation method of any one of claims 1 to 9, wherein the surface of the fabric substrate of the super-hydrophobic antibacterial fabric is attached with a fluorocarbon coupling agent and a hydrophobic silica nanoparticle cross-linked composite coating, and the super-hydrophobic antibacterial fabric with photothermal effect combines passive super-hydrophobic antibacterial adhesion with active photothermal sterilization in antibacterial applications, and the antibacterial rate of Staphylococcus aureus and Escherichia coli can reach 100% under near-infrared light conditions. The antibacterial performance is strong and the antibacterial range is wide.

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