Preparation method and application of inorganic composite powder and reversible thermochromic antibacterial organic silicon fiber

Abstract

The invention discloses a preparation method and application of inorganic composite powder and reversible thermochromic antibacterial organosilicone fibers, the inorganic composite powder is TiO2 (at) AgI, AgI is dispersed and loaded on a TiO2 base material in a nanometer form, the mass ratio of AgI to TiO2 is 1: (1-50), and the particle size is 100 nm to 5 [mu] m; agI is dispersed and loaded on a TiO2 base material in a nanometer form to obtain a heterojunction, so that the composite material has reversible thermochromism performance and antibacterial property; according to the present invention, the organic silicon fiber is added and spun, such that the reversible thermochromism of the cyclic discoloration at the medium-high temperature can be achieved, the antibacterial non-toxic and high strength can be achieved, the technical bottlenecks of poor thermal stability, low discoloration threshold temperature and low response sensitivity of the existing RTFs can be broken through, the defects of low air permeability and small application range of the existing organic silicon antibacterial dressing can be improved, and the application prospect is broad. And the method has important practical significance and application value for expanding the application field of the organic silicon material.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic silicon fibers, and more specifically, relates to a preparation method and application of an inorganic composite powder and a reversible thermochromic antibacterial organic silicon fiber. Background Art

[0002] In recent years, reversible thermochromic fibers (RTFs) have shined in human health detection, thermal management, intelligent anti-counterfeiting, temperature visualization and warning due to their intelligent external response color change function. RTFs are a kind of intelligent flexible material that can display different colors as the ambient temperature changes. While it has the advantages of fiber flexibility and easy processing and intelligent color change in response to external stimuli, it can also be recycled many times. Compared with traditional contact temperature measurement, RTFs have the advantage of being able to quickly judge the temperature range through the change of the fiber's own color, which has attracted great attention from researchers. However, most fiber substrates have the disadvantages of poor thermal stability and low color change threshold temperature, which makes the current RTFs only suitable for low temperature environments. This greatly limits the application of RTFs, and some materials may even be toxic to organisms.

[0003] Few RTFs can achieve the characteristic of changing color in high temperature environments, which is mainly attributed to the shortcomings of common fiber materials that are not resistant to high temperatures and have poor thermal stability. Currently, polyester fibers are the mainstream of commercially available color-changing fibers, and the color-changing materials used are also mainly organic color-changing materials. Therefore, the color-changing fibers produced and sold are only suitable for low-temperature color-changing application scenarios, such as human thermal management, medical fields, etc. There is a lack of research and development and market for medium and high temperature, especially high temperature color-changing fibers.

[0004] Silicone materials have become the preferred materials in many emerging technology fields due to their excellent high temperature resistance. The preparation of silicone materials into flexible and processable reversible thermochromic fibers is expected to further expand their application in high-end scenes.

[0005] At the same time, as a common high-performance material, silicone materials have the advantages of high tensile strength, good flexibility, corrosion resistance, and good biocompatibility, and are therefore widely used in the fields of biomedical materials. However, there are still the following problems in the process of use: (1) Although quite a number of reports have confirmed that silicone polymers have excellent biocompatibility, biomedical silicone materials are usually in direct contact with human tissues during use, which can easily cause bacterial adhesion and exist in the form of biofilms, thereby protecting the embedded bacteria from antimicrobial treatment and host immune defense, which seriously limits their clinical application; (2) In recent years, the antibacterial silicone materials reported are mostly in the form of gels and films. Although this has solved the disadvantage of silicone materials having no antibacterial ability to a certain extent, the permeability of such materials usually depends on the formulation and structural design. Materials with poor permeability may increase the risk of secondary tissue infection.

[0006] In contrast, making antibacterial organosilicon materials into fibrous form can endow organosilicon antibacterial materials with excellent tensile strength and resilience. In addition, due to the unique flexibility, processability and structural designability of fiber materials, they can be compounded with a variety of functional materials to prepare advanced composite materials with adjustable properties. This composite strategy not only retains the mechanical advantages and flexible characteristics of the fiber itself, but also endows the material with new functions through the synergistic effect of components, so as to meet the diverse application requirements and is more suitable for scenarios with repeated deformation, such as antibacterial bandages, antibacterial protectors, etc. If the organosilicon antibacterial fiber is further constructed into a fabric form through a weaving process, it can synergistically achieve a perfect balance between multi-scale breathable structure and high-efficiency antibacterial performance, so as to meet the stringent requirements of high-end application scenarios such as medical protection and smart wear. However, since organosilicon fibers belong to cross-linked polymers, production and processing are relatively difficult, and there are few reports on the fibrosis of organosilicon materials at present, and the research reports on organosilicon antibacterial fibers are even rarer. Summary of the Invention

[0007] The object of the present invention is to address the above deficiencies and provide a preparation method and application of an inorganic composite powder and a reversible thermochromic antibacterial organosilicon fiber. The inorganic composite powder obtains a heterojunction by dispersing and loading AgI in nano form on a TiO2 substrate, making it have both reversible thermochromic performance and antibacterial properties; adding it and spinning it into an organosilicon fiber can achieve reversible thermochromism with cyclic color change at medium-high temperatures, which is antibacterial, non-toxic and has high strength. It can break through the technical bottlenecks of poor thermal stability, low color change threshold temperature and low response sensitivity of existing RTFs, improve the low air permeability of existing organosilicon antibacterial dressings, and make up for their small scope of application, which has important practical significance and application value for expanding the application fields of organosilicon materials.

[0008] To achieve the above object, the present invention is realized through the following technical solutions: In the first aspect, the present invention provides an inorganic composite powder, the inorganic composite powder is TiO2@AgI, wherein AgI is dispersed and loaded on the TiO2 substrate in nano form, and the mass ratio of AgI to TiO2 is 1:(1~50); the particle size of TiO2@AgI is 100nm~5μm.

[0009] Preferably, the mass ratio of AgI to TiO2 in TiO2@AgI is 1:(5~20), and further preferably 1:(10~11); the particle size of TiO2@AgI is 100 nm~500 nm.

[0010] Preferably, the TiO2 is rutile phase, anatase phase or a mixture of the two phases. Further preferably, the TiO2 is rutile phase.

[0011] Second aspect, the present invention also provides a preparation method of the inorganic composite powder material described in the first aspect, including: Mix TiO2, KI and AgNO3 in deionized water, and prepare TiO2@AgI powder by the dissolution-precipitation method; Among them, the mass ratio of TiO2, KI and AgNO3 is 1:(0.95~1.05):(5~50), and the reaction time of the dissolution-precipitation method is 5 min to 120 min.

[0012] Preferably, the mass ratio of TiO2, KI and AgNO3 is 1:(0.98~1.02):(10~15), and the reaction time is 5 min to 60 min; more preferably, the reaction time is 5 min to 30 min.

[0013] Preferably, after the dissolution-precipitation method reaction is completed, the obtained product is ball-milled by a ball mill.

[0014] Preferably, the ball-milling parameters include: the ball-milling time is 20 min to 60 min, the rotation speed is 200 rpm to 600 rpm, and the ball-to-material ratio is (1.4~4.1):1.

[0015] Third aspect, the present invention also provides a reversible thermochromic antibacterial silicone fiber. The raw materials of the silicone fiber include silicone oil spinning solution, the TiO2@AgI powder material described in the first aspect, a catalyst, an inhibitor and a curing accelerator; the silicone oil spinning solution includes vinyl silicone oil and hydrogen silicone oil with a mass ratio of 1:(0.8~1.4). The vinyl silicone oil includes terminal vinyl silicone oil and side vinyl silicone oil, and the addition amount of side vinyl silicone oil in the vinyl silicone oil is 0~20 wt%; the addition amount of the TiO2@AgI powder material is 0.5 wt% to 4.5 wt% of the total amount of the silicone oil spinning solution; the addition amounts of the catalyst, the inhibitor and the curing accelerator are each 0.1 wt% to 1 wt% of the total amount of the silicone oil spinning solution.

[0016] Preferably, the mass ratio of the vinyl silicone oil and the hydrogen silicone oil is 1:(1.1~1.2), the addition amount of the side vinyl silicone oil in the vinyl silicone oil is 14 wt% to 16 wt%, and the addition amount of the TiO2@AgI powder material is 1 wt% to 5 wt% of the total amount of the silicone oil.

[0017] Preferably, the terminal vinyl silicone oil is divinyl-terminated phenyl silicone oil, with a viscosity of 500 cp to 3000 cp and a vinyl content of 0.8% to 1.2%; it includes one or more of α,ω-vinyl polymethylphenylsiloxane, or α,ω-vinyl poly(methylphenylsiloxane-dimethylsiloxane) or α,ω-vinyl poly(dimethylsiloxane-diphenylsiloxane) in any mixture; more preferably, it is α,ω-vinyl polymethylphenylsiloxane, with a viscosity of 950 to 1050 cp and a vinyl content of 0.8% to 1.2%.

[0018] Preferably, the side vinyl silicone oil is terminal-side multi-vinyl phenyl silicone oil, with a viscosity of 500 cp to 10000 cp and a vinyl content of 2.3% to 2.7%; it includes one or two of α,ω-vinyl poly(methylphenylsiloxane-methylvinylsiloxane) or α,ω-vinyl poly(phenylvinylsiloxane-methylphenylsiloxane) in any mixture; preferably, it is α,ω-vinyl poly(methylphenylsiloxane-methylvinylsiloxane), with a viscosity of 5000 cp and a vinyl content of 2.3% to 2.7%.

[0019] Preferably, the hydrogen-containing silicone oil is side hydrogen-containing silicone oil, including α,ω-dimethyl polymethylhydrogen siloxane, with a viscosity of 80 cp to 100 cp, and the hydrogen content in the hydrogen-containing silicone oil is 0.36% to 1.6%; more preferably, the hydrogen content is 0.75%.

[0020] Preferably, the catalyst is a platinum catalyst, including any one of Speier catalyst and Karstedt catalyst, and the platinum concentration in the platinum catalyst is 1000 ppm to 10000 ppm; more preferably, Karstedt catalyst is used, and the platinum concentration is 3000 ppm; the inhibitor can be ethynylcyclohexanol, 2-methyl-3-butanol-2-ol or butynediol, preferably ethynylcyclohexanol, and its solvent can be ethanol or isopropanol, preferably isopropanol, and the inhibitor concentration is 1000 ppm to 10000 ppm, more preferably 4500 ppm to 5500 ppm; the curing accelerator is a borate ester, including trimethyl borate, triethyl borate, tributyl borate or bis(pinacolato)diboron, and the curing accelerator concentration is 1000 ppm to 10000 ppm.

[0021] Fourthly, the present invention also provides a preparation method of the reversible thermochromic antibacterial silicone fiber described in the third aspect, including: Mix TiO2, KI and AgNO3 in deionized water, and prepare TiO2@AgI powder material by dissolution-precipitation method; Mix vinyl silicone oil and hydrogen-based silicone oil evenly in proportion to prepare a silicone oil spinning solution; Add the TiO2@AgI powder material to the silicone oil spinning solution and disperse it evenly; Add a catalyst, an inhibitor, and a curing accelerator to the silicone oil spinning solution containing the TiO2@AgI powder material, and stir to obtain a spinning solution prepolymer; Add the above spinning solution prepolymer to a spinning device, and spin it by inducing cross-linking and curing through air heating.

[0022] Preferably, after the dissolution-precipitation method reaction ends, the obtained product is ball-milled by a ball mill.

[0023] Preferably, the ball-milling parameters include: the ball-milling time is 20 min to 60 min, the rotation speed is 200 rpm to 600 rpm, and the ball-to-material ratio is (1.4 to 4.1):1.

[0024] Preferably, the temperature during the preparation of the silicone oil spinning solution is 20°C to 50°C, and the stirring rate is 100 rpm to 1000 rpm; the temperature for heating-induced cross-linking and curing is 150°C to 250°C; more preferably, the temperature during the preparation of the silicone oil spinning solution is 25°C, and the stirring rate is 140 rpm to 160 rpm; the temperature for heating-induced cross-linking and curing is 200°C to 220°C.

[0025] Preferably, the spinning device includes a constant-pressure injection pump, a spinneret, a heat-insulating bracket, a heating sleeve, a temperature control device, and a collection device. The spinning solution prepolymer is pushed into the spinneret by the constant-pressure injection pump, and is output to the collection device through the spinneret for curing and forming. The heating sleeve is sleeved outside the spinneret, and the temperature control device is used to adjust the temperature of the heating sleeve, so that the spinning solution is stretched and pulled while passing through the spinneret and is induced to cross-link and cure in situ through air heating.

[0026] In a fifth aspect, the present invention also provides an application of the reversible thermochromic antibacterial silicone fiber described in the first aspect in the preparation of reversible thermochromic materials. Specifically, the prepared reversible thermochromic materials can be used for thermal management, intelligent anti-counterfeiting, warning in high-temperature scenarios, and color visualization, etc.

[0027] In a sixth aspect, the present invention also provides an application of the reversible thermochromic antibacterial silicone fiber described in the first aspect in the preparation of antibacterial materials. Specifically, the prepared antibacterial materials can be used for antibacterial dressings, antibacterial bandages, antibacterial protective gear, intelligent wearables, etc.

[0028] Compared with the prior art, the beneficial effects of the present invention are: The inorganic composite powder provided by the present invention has both reversible thermochromic properties and antibacterial properties. On the one hand, using AgI as the thermochromic material and TiO2 as the white background, the composite powder material has distinct thermochromic properties. At the same time, the silver salt is dispersed as a nanomaterial, which can provide excellent rapid response function of thermochromism and obtain a very high temperature response sensitivity. On the other hand, the composite powder can effectively inhibit the recombination of photo-generated carriers, overcome the disadvantages of poor light stability and easy decomposition of AgI, and improve the visible light photocatalytic utilization rate of TiO2. The coexistence of two mechanisms of AgI / TiO2 heterojunction photocatalysis and AgI metal ion release realizes the dual-mode synergistic antibacterial effect of photocatalytic sterilization - metal ion release antibacterial.

[0029] The present invention adds and spins the inorganic composite powder to obtain a silicone fiber, which can realize reversible thermochromism with cyclic color change at medium-high temperatures, and has antibacterial, non-toxic and high strength properties. It can break through the technical bottlenecks of poor thermal stability, low color change threshold temperature and low response sensitivity of existing RTFs, improve the low air permeability of existing silicone antibacterial dressings, and make up for the disadvantages of their small application scope, which has important practical significance and application value for expanding the application fields of silicone materials.

[0030] The mixed components of the present invention are subjected to a hydrosilylation reaction and air heating is used to induce in-situ curing and fiber formation of the spinning solution to obtain a reversible thermochromic antibacterial silicone fiber with high strength. The preparation process is more non-toxic and environmentally friendly, the process is simple, the cycle is short, and continuous production can be carried out. Brief Description of the Drawings

[0031] Figure 1 Microstructural characterization of the TiO2@AgI powder prepared in Example 1; among them, (a1)-(a3) are SEM images and particle size distribution calculations of TiO2@AgI (11:1) ; (b1)-(b3) are TEM images of TiO2@AgI (11:1) ; (c) is the elemental distribution of TiO2@AgI (11:1) Figure 2 Microstructural characterization of the reversible thermochromic antibacterial silicone fiber prepared in Example 1; among them, (c1) is the longitudinal morphology of TiO2@AgI (11:1) @SiF-2 under a super-depth three-dimensional microscope and SEM; (c2) is the white light photograph of TiO2@AgI (11:1) @SiF-2; (c3) is the cross-sectional morphology of TiO2@AgI (11:1) @SiF-2 under a super-depth three-dimensional microscope and SEM Figure 3Surface elemental distribution diagram of the reversible thermochromic antibacterial silicone fiber prepared in Example 1; wherein, (a) is the elemental distribution of the fiber cross-section; (b) is the elemental distribution of the fiber longitudinal direction; Figure 4 Antibacterial performance comparison diagram of raw cotton and the reversible thermochromic antibacterial silicone fiber prepared in Example 1; Figure 5 Comparison of the bacteriostatic rate test results of raw cotton and the reversible thermochromic antibacterial silicone fiber prepared in Example 1; Figure 6 In vitro cytotoxicity test results of the reversible thermochromic antibacterial silicone fiber prepared in Example 1; wherein, (a) is the cell survival state after culturing L929 cells with different concentrations of the antibacterial powder prepared in Example 1 and the control group for 12 h; (b) is the cell viability; Figure 7 Optoelectronic property characterization of the TiO2@AgI powder and the reversible thermochromic antibacterial silicone fiber prepared in Example 1; wherein, (a) is the semiconductor energy band gap (Tauc) diagram of AgI, TiO2 and TiO2@AgI powders; (b) is the ultraviolet-visible light reflection spectrum diagram of AgI, TiO2 and TiO2@AgI powders; (c) is the ultraviolet-visible light reflection spectrum diagram of TiO2@AgI powder and the reversible thermochromic antibacterial silicone fiber; Figure 8 Antibacterial mechanism diagram of the reversible thermochromic antibacterial silicone fiber of the present invention; Figure 9 Comparison of the light stability performance of the products obtained in Example 1 and Comparative Example 1; wherein, (a) is the comparison diagram of the pure AgI spinning solution prepared in Comparative Example 1 and the composite spinning solution prepared in Example 1 after being placed under the lamp for 15 min; (b) is the photo of the silicone fiber prepared in Comparative Example 1 turning black after being placed for 24 h; Figure 10 Color-changing optical photo of the silicone fiber prepared in Comparative Example 1; wherein, (a) is before color change at low temperature, (b) is after color change at high temperature, (c) is the comparison diagram before and after being placed at room temperature for 24 h; Figure 11 Effect of the addition amount of different TiO2 on the color-changing performance of TiO2@AgI powder; wherein, on the left is the color block diagram of TiO2@AgI under different TiO2 addition amounts, and on the right is the color parameter diagram of TiO2@AgI under different TiO2 addition amounts; Figure 12 Effect of the particle size distribution of TiO2@AgI powder on the mechanical properties of the reversible thermochromic antibacterial silicone fiber; wherein, (a) is the comparison of the tensile strength of different examples; (b) is the particle size distribution of Example 9; (c) is the particle size distribution of Examples 10 to 17; Figure 13 Verification diagram of the rapid color change characteristics of the reversible thermochromic antibacterial silicone fiber prepared in Example 18; Figure 14 Diagram showing the color change sensitivity of the reversible thermochromic antibacterial silicone fiber prepared in Example 18; Figure 15 For different TiO2@AgI (11:1) Effect of the addition amount on the tensile properties of the reversible thermochromic antibacterial silicone fiber; among them, (a) is the influence curve of different addition amounts on the fiber tensile strength; (b) is the stress-strain curve of the fiber prepared in Example 18; (c) is the performance diagram of 150 cycles of 100% elongation rate of the fiber prepared in Example 18; Figure 16 For different TiO2@AgI (11:1) Effect of the addition amount on the color change performance of the reversible thermochromic antibacterial silicone fiber; among them, (a) is the influence of different TiO2@AgI (11:1) addition amounts on the fiber color difference value; (b) is the color difference comparison of the fiber prepared in Example 18 at 20 °C and 150 °C. Detailed implementation manners

[0032] In the preparation process of the reversible thermochromic antibacterial silicone fiber of the present invention, TiO2@AgI is used as the functional material. The doping amount of TiO2@AgI will not only affect the color change performance and antibacterial performance, but also affect the mechanical properties of the fiber. Therefore, on the premise of ensuring that the spinning solution is completely cured under high temperature conditions, the mass ratio of TiO2 and AgI and the doping amount of TiO2@AgI are adjusted to obtain a silicone fiber with both high strength and excellent color change performance and antibacterial performance, thereby broadening the application of silicone materials in high temperature scene detection, temperature visualization, and biomedical materials.

[0033] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings and specific examples.

[0034] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0035] The raw materials used in the specific examples are as follows: Terminal vinyl silicone oil: α, ω-vinyl polymethylphenylsiloxane, 1000 cp, Guoyan Chemical New Materials Co., Ltd.; Side vinyl silicone oil: α, ω-vinyl poly(methylphenylsiloxane-methylvinylsiloxane), 5000 cp, Guoyan Chemical New Materials Co., Ltd.; Amino silicone oil: α, ω-dimethylpolymethylhydrogensiloxane, hydrogen content 0.75%, Shenzhen Jipeng Silicon Fluoride Materials Co., Ltd.; Inhibitor: Weigh 0.05 g of ethynylcyclohexanol (Shanghai Aladdin Biochemical Technology Co., Ltd.) and add it to isopropanol. Dilute it to 10 mL with a volumetric flask to prepare a solution with a concentration of 5000 ppm. Curing accelerator: Weigh 0.05 g of bis(pinacolato)diboron (Shanghai Aladdin Biochemical Technology Co., Ltd.) and add it to isopropanol. Dilute it to 10 mL with a volumetric flask to prepare a solution with a concentration of 5000 ppm. Catalyst: Karstedt catalyst, platinum content 3000 ppm, Shenzhen Kejunchi Industry Co., Ltd.

[0036] The measurement methods in the following examples include: (1) Use an INSTRON-3365 double-arm material testing machine to test the mechanical properties of the prepared silicone fibers. Cut the fibers into 4 cm lengths according to the national standard for testing the tensile properties of chemical fiber staple fibers, GB / T 14337-2022, and wrap both ends of the fibers with label paper. During the test, the sensor range is 0-8 N, and the tensile speed is 4 cm·min -1 , and the gauge length is 2 cm. To make the measurement results more accurate, each group of fiber samples is tested 20 times on average to obtain the average tensile strength and elongation at break. In addition, keeping the tensile rate of the fibers constant, at 100% elongation, the fibers are subjected to 150 cycles of tensile testing to study the fatigue resistance of the silicone fibers.

[0037] (2) Linear density is one of the most important indicators to characterize the fineness of fibers. The commonly used units are tex (N t (tex)), dtex (N dt (dtex)) and denier (ND). Measure and cut a section of silicone fiber, accurately weigh the mass of the fiber on an electronic balance, and then calculate the linear density of the silicone fiber through the formula. The calculation formula is as follows: ; where: L is the length of the fiber (m), and m is the mass of the fiber (g).

[0038] (3) The colors of the inorganic composite powder and the silicone fibers at different temperatures are photographed under the D65 standard illuminant specified by the International Commission on Illumination. The photographed photos are imported into Adobe Photoshop 2023 software for color parameter analysis. The color change sensitivity and rapid color change characteristics are analyzed in combination with the infrared thermal image.

[0039] (4) The antibacterial performance test was carried out with reference to the third part, the oscillating method, of the national standard GB / T 20944.3-2008. Using pure cotton cloth (CF) as the control sample, after the silicone fibers and CF were washed according to the standard, they were respectively cut into short fibers of 5 mm and fragments of 5 mm × 5 mm and put into a high-pressure sterilizer for treatment for 15 min. Subsequently, the antibacterial fibers and CF were respectively put into Erlenmeyer flasks and a certain amount of PBS buffer solution and inoculated bacterial solution were added. The bacterial strains were Staphylococcus aureus and Escherichia coli. At 24 °C ± 1 °C, at 150 r·min -1 , oscillate for 18 h. 1 mL of the solution was drawn from each flask, diluted and dropped on the culture dish and spread evenly for cultivation. Finally, the colony numbers of the two bacterial strains were counted and photographed respectively. The viable bacteria concentration K and the antibacterial rate Y were calculated according to the following formulas: ; ; Among them, K is the viable bacteria concentration (CFU·mL -1 ), Z is the average value of the colony numbers on the two plates, R is the dilution factor, Y is the antibacterial rate of the sample (%), W t is the average value of the viable bacteria concentration in the flask after 18 h of oscillating contact of the control sample CF (CFU·mL -1 ), Q t is the average value of the viable bacteria concentration in the flask after 18 h of oscillating contact of the fiber (CFU·mL -1 ).

[0040] (5) Mouse fibroblasts (L929) were used to evaluate the cytotoxicity of the silicone fibers. L929 was cultured in a medium containing 10% fetal bovine serum, 1% P / S penicillin-streptomycin and 89% MEM, and the culture temperature was 37 °C, 5% CO2. The silicone fibers were cut into certain blocks (10 mg, 20 mg, 40 mg and 100 mg). After high-pressure sterilization, the sterilized samples were added to 10 mL of the medium and soaked at 37 °C for 24 h. The L929 cells in the logarithmic growth phase were treated according to the above grouping, and after being cultured in an incubator at 5% CO2, 37 °C for 12 h, they were photographed under a 100-fold white light microscope. The medium was removed, the wells were washed 3 times with PBS, 10% CCK8 medium was added at 100 μL / well, and then cultured in an incubator at 5% CO2, 37 °C for 2 h, and the optical density value (OD) at a wavelength of 450 nm was detected with an enzyme-labeling instrument. The relative viability of L929 cells ( R ) was calculated according to the following formula: ; wherein, R is the relative cell viability (%), OD sample is the OD value of the experimental sample, OD background is the background OD value, OD 0 is the average OD value of the control group.

[0041] Example 1: This example provides a reversible thermochromic antibacterial silicone fiber, and its preparation method includes the following steps: S1: Synthesize TiO2@AgI powder Take a clean container and weigh 11 g of TiO2, then add 500 mL of deionized water and stir at a stirring rate of 1000 rpm for 10 min to fully disperse TiO2; weigh 0.80 g of AgNO3 and pour it into the above-mentioned deionized water and stir at a speed of 1000 rpm for 10 min to fully dissolve it; take another clean container, weigh 0.78 g of KI, add 10 mL of deionized water and dissolve it by ultrasonic wave, then pour it into the above AgNO3 solution and react in the dark for 30 min; perform suction filtration and drying on the obtained TiO2@AgI dispersion liquid and set it aside for later use. This product is denoted as TiO2@AgI (11:1) .

[0042] S2: Preparation of silicone oil spinning solution Take a clean container and successively add 32.5 g of α,ω-vinyl polymethylphenylsiloxane (1000 cp), 4.8 g of α,ω-vinyl poly(methylphenylsiloxane-methylvinylsiloxane) (5000 cp) and 2.7 g of α,ω-dimethylpolymethylhydrosiloxane (hydrogen content 0.75%), and mix the silicone oil evenly at a stirring rate of 150 rpm to obtain a silicone oil spinning solution.

[0043] S3: Add TiO2@AgI to the silicone oil spinning solution Add 0.8 g (2% of the mass of the silicone oil spinning solution) of TiO2@AgI prepared in S1 to the silicone oil spinning solution prepared in S2, and stir at a stirring rate of 2000 rpm for 6 h to fully disperse TiO2@AgI into the silicone oil spinning solution.

[0044] S4: Prepolymerization Add 0.1% of the inhibitor ethynylcyclohexanol (5000 ppm) based on the total mass of the silicone oil to the silicone oil spinning solution obtained in S3, and stir for 5 min to ensure uniform distribution of the inhibitor in the spinning solution; then add 3000 ppm of the platinum catalyst Karstedt and 0.1% of the bis(pinacolato)diborate based on the total mass of the silicone oil, control the system temperature at 25 °C, and stir at a speed of 150 rpm for about 15 min to pre-polymerize the spinning solution to a spinnable state, that is, obtain the pre-polymer of the spinning solution.

[0045] S5: High-temperature air-induced cross-linking and curing into filaments After thoroughly degassing the pre-polymer of the spinning solution prepared in S4, add it to the spinning equipment, pour it into a 50 mL syringe, and clamp it on a constant-pressure injection pump. The pushing speed of the constant-pressure injection pump is set to 0.65 mL·min -1 , and measure that the actual heating temperature at the center of the heating sleeve is about 200 °C to 220 °C. When the pre-polymer of the spinning solution passes through the heating sleeve at a constant speed, it is stretched and tractioned while cross-linking and curing in-situ, and is completely cured and formed when entering the rotating collection cage, obtaining a reversible thermochromic antibacterial silicone fiber product, code-named TiO2@AgI (11:1) @SiF-2.

[0046] The inorganic composite powder TiO2@AgI prepared in this example (11:1) The morphology and structure are shown in Figure 1 , it can be seen from the figure that under the SEM picture, TiO2@AgI (11:1) is at the nanometer level and presents an irregular state. The black particles scattered in the TEM picture are AgI, and the surface element distribution shows that TiO2@AgI (11:1) is composed of four elements: Ti, O, Ag, and I.

[0047] The reversible thermochromic antibacterial silicone fiber TiO2@AgI prepared in this example (11:1) @SiF-2's microscopic morphology is shown in Figure 2 , it can be seen that the fiber cross-section presents a regular circle, the longitudinal direction is smooth without wrinkles. Measure the fiber diameter at 10 different points on the same fiber, and calculate that the average fiber diameter is 300 ± 14 μm; Figure 3 The surface element distribution shown in the figure shows that in addition to containing Ti, O, Ag, and I elements, it also contains Si and C elements; through calculation, the color difference before and after thermochromism of the fiber at this time is 25.72.

[0048] Use Escherichia coli and Staphylococcus aureus to evaluate the antibacterial performance of the reversible thermochromic antibacterial silicone fiber TiO2@AgI (11:1) @SiF-2 prepared in this example, see Figure 4 andFigure 5 , it can be seen that there are no visible colonies in the culture media of TiO2@AgI (11:1) @SiF-2 at different dilution multiples, showing excellent antibacterial performance with an antibacterial rate of 99.99%. In addition, as Figure 6 shown, in the in vitro cytotoxicity test, it was also observed that TiO2@AgI (11:1) @SiF-2 extracts at different concentrations showed high cell activity after co-culturing with L929 cells for 12 h, and the cell viability reached over 98%, indicating its excellent biosafety.

[0049] The antibacterial mechanism of the reversible thermochromic antibacterial silicone fiber described in the present invention is as Figure 7 shown: After AgI and TiO2 form a heterojunction, the CB of TiO2 is located between the VB and CB of AgI; when irradiated with light with energy higher than its own Eg, electrons on the VB of AgI are excited and transition to the CB to generate e cb - while leaving h vb + in the valence band, that is, photo-generated carriers; subsequently, the electrons on the CB of AgI will migrate to the CB of TiO2, while h vb + stays on the VB of AgI. Since TiO2@AgI is uniformly dispersed in the fiber, according to the principle of thermodynamics, O2 adsorbed on the fiber surface will capture e - to form superoxide radical anions (·O2 - ), while h + will convert H2O or OH - into ·OH. These two generated free radicals have strong activity and undergo redox reactions when contacting Escherichia coli and Staphylococcus aureus. Among them, reactive oxygen species (ROS) can penetrate the bacterial cell wall and interfere with the bacterial respiration and electron transport system to achieve rapid killing of bacteria. In the dark environment, AgI can also assist in playing an antibacterial role. The solubility product constant Ksp of AgI = 8.3×10⁻ 17 , and it can slowly release Ag + . A small amount of existing Ag + will, under the microkinetic effect, penetrate into the microbial cell membrane when contacting microorganisms and react with -SH on the proteins in their bodies, causing microbial DNA synthesis and thus leading to their death.

[0050] From Figure 7 the Tauc plot of (a), it can be seen that AgI, TiO2, and TiO2@AgI (11:1)The band gap values of the three materials are 2.73 eV, 2.97 eV, and 2.85 eV respectively, which are close to the theoretical values. Secondly, the lower the band gap (Eg), the smaller the energy difference between the valence band (VB) and the conduction band (CB) of the material, and the easier the photo-generated carriers generated under light illumination are to recombine. It is observed that the band gap of pure AgI is only 2.73 eV, and it is very easy to generate Ag particles due to the recombination of electron-hole pairs, which in turn causes the material to turn black and the luster to decrease. In contrast, the band gap of the composite TiO2@AgI (11:1) has been improved; as can be seen from Figure 7 the UV-Vis diffuse reflectance spectrum in (b), pure AgI has absorption in the visible light range, which indicates that it is prone to decomposition under general environmental conditions; as can be seen from Figure 7 (c), the absorption spectra of TiO2@AgI powder and TiO2@AgI (11:1) @SiF-2 are basically the same, which indicates that the structure of the silicone fiber sample doped with TiO2@AgI powder has not changed. Since both TiO2@AgI powder and silicone fiber material have good biocompatibility, TiO2@AgI (11:1) @SiF-2 is also non-toxic to biological cells and can be safely applied.

[0051] The present invention verifies the influence of the addition amount of TiO2 on the performance of reversible thermochromic antibacterial silicone fibers through the following examples and comparative examples.

[0052] Comparative Example 1: This comparative example provides a silicone fiber, and its preparation method does not include the synthesis of TiO2@AgI powder. Except that the TiO2@AgI powder added to the silicone oil spinning solution is replaced with AgI powder in the remaining steps, the preparation is carried out with reference to Example 1, and the obtained silicone fiber product is designated as AgI@SiF.

[0053] The tensile strength of the silicone antibacterial fiber under this process is 0.81 cN·tex measured by a double-arm material testing machine -1 , the fiber bacteriostatic rate is 81.12%, and the color difference before and after thermochromism is 2.06. Since the silicone fiber prepared in this comparative example has only one antibacterial mechanism of anion precipitation, its antibacterial effect is far inferior to that of the reversible thermochromic antibacterial silicone fiber added with TiO2@AgI composite powder.

[0054] As can be seen from Figure 9 (a), the spinning solution containing pure AgI turns black under indoor light in 15 minutes, while the spinning solution containing TiO2@AgI (11:1)The spinning solution remains almost unchanged and has excellent light stability. In contrast, the absorption spectrum of TiO2 is mainly in the ultraviolet region, and the utilization rate of visible light is less than 4%. This usually requires ultraviolet excitation to generate electron-hole pairs to produce antibacterial function, and the conditions are relatively harsh. After compounding, the absorption spectrum of TiO2@AgI (11:1) shows a red shift compared with that of pure AgI, indicating that the utilization rate of visible light of the composite material has been improved, and antibacterial function can be produced under visible light irradiation; from Figure 9 As can be seen from (b), the color of the fiber prepared by directly adding AgI to the spinning solution gradually turns black after being placed for 24 h.

[0055] From Figure 10 As can be seen from (a) before low-temperature color change and (b) after high-temperature color change, compared with the case where AgI is loaded on the surface of TiO2 and dispersed as nano-powders, due to the lack of a white TiO2 background, the thermochromic color difference caused by directly adding AgI under the same dosage is much smaller than the color development effect of TiO2 loading, and the high-temperature color development color is not bright without the titanium dioxide background; while from Figure 10 As can be seen from (c), the color of the silicone fiber spun by directly adding AgI powder turns black after being placed at room temperature for 24 h, indicating that its storage stability is poor.

[0056] Example 2: Referring to Example 1, 11 g of TiO2 in S1 was replaced with 10 g of TiO2, and other conditions and operation steps were the same. The prepared sample was designated as TiO2@AgI (10:1) @SiF-2.

[0057] Example 3: Referring to Example 1, 11 g of TiO2 in S1 was replaced with 9 g of TiO2, and other conditions and operation steps were the same. The prepared sample was designated as TiO2@AgI (9:1) @SiF-2.

[0058] Example 4: Referring to Example 1, 11 g of TiO2 in S1 was replaced with 7.5 g of TiO2, and other conditions and operation steps were the same. The prepared sample was designated as TiO2@AgI (7.5:1) @SiF-2.

[0059] Example 5: Referring to Example 1, 11 g of TiO2 in S1 was replaced with 5 g of TiO2, and other conditions and operation steps were the same. The prepared sample was designated as TiO2@AgI (5:1) @SiF-2.

[0060] Example 6: Referring to Example 1, replace 11 g of TiO2 in S1 with 12.5 g of TiO2, and keep other conditions and operation steps the same. The prepared sample is designated as TiO2@AgI (12.5:1) @SiF-2

[0061] Example 7: Referring to Example 1, replace 11 g of TiO2 in S1 with 15 g of TiO2, and keep other conditions and operation steps the same. The prepared sample is designated as TiO2@AgI (15:1) @SiF-2

[0062] Example 8: Referring to Example 1, replace 11 g of TiO2 in S1 with 20 g of TiO2, and keep other conditions and operation steps the same. The prepared sample is designated as TiO2@AgI (20:1) @SiF-2

[0063] Figure 11 The color block diagram (left) and color parameters (right) of TiO2@AgI powder under different TiO2 addition amounts are shown. When the addition amount of TiO2 is 11 g, the overall color difference of the thermochromic powder reaches the maximum value, about 35.33; while the color differences of the thermochromic powders in the other batches are all less than 30, and the color differences of the prepared fibers before and after color change are poor. This is sufficient to show that when the addition amount of TiO2 is 11 g, the TiO2@AgI powder can achieve the best color change performance

[0064] At the same time, through calculation, when the addition amount of TiO2 is 11 g, the prepared reversible thermochromic antibacterial silicone fiber can achieve the best antibacterial performance; the antibacterial rates of the antibacterial fibers obtained in the other batches are all lower than 99.99%, which is sufficient to show that TiO2@AgI (11:1) @SiF-2 has the best antibacterial performance

[0065] The present invention analyzes the influence of the particle size and distribution of TiO2@AgI (11:1) on the mechanical properties of fibers

[0066] Example 9: This example provides a reversible thermochromic antibacterial silicone fiber, and its preparation method includes the following steps S1: Synthesize TiO2@AgI powder Take a clean container and weigh 11 g of TiO₂. Then add 500 mL of deionized water and stir at a stirring rate of 1000 rpm for 10 min to fully disperse TiO₂; weigh 0.80 g of AgNO₃ and pour it into the above-mentioned deionized water, and stir at a speed of 1000 rpm for 10 min to fully dissolve it; take another clean container, weigh 0.78 g of KI, add 10 mL of deionized water, dissolve it by ultrasonic treatment, and then pour it into the above AgNO₃ solution, and react in the dark for 30 min; perform suction filtration and drying on the obtained TiO₂@AgI dispersion. Use a ball mill to ball mill the sample for 20 min at a rotation speed of 600 rpm and a ball-to-material ratio of 4.1:1. After ball milling, the particle size range of TiO₂@AgI is 120 - 550 nm.

[0067] S2: Preparation of silicone oil spinning solution Take a clean container and successively add 32.5 g of α,ω-vinyl polymethylphenylsiloxane (1000 cp), 4.8 g of α,ω-vinyl poly(methylphenylsiloxane-methylvinylsiloxane) (5000 cp), and 2.7 g of α,ω-dimethylpolymethylhydrosiloxane (hydrogen content 0.75%). Mix the silicone oil evenly at a stirring rate of 150 rpm to obtain a silicone oil spinning solution.

[0068] S3: Add TiO₂@AgI to the silicone oil spinning solution Add 0.8 g (2% of the mass of the silicone oil spinning solution) of TiO₂@AgI prepared in S1 to the silicone oil spinning solution prepared in S2, and stir at a stirring rate of 2000 rpm for 6 h to fully disperse TiO₂@AgI into the silicone oil spinning solution.

[0069] S4: Prepolymerization Add ethynylcyclohexanol (5000 ppm), which is equivalent to 0.1% of the total mass of the silicone oil, as an inhibitor to the silicone oil spinning solution obtained in S3, and stir for 5 min to ensure uniform distribution of the inhibitor in the spinning solution; then add 3000 ppm of platinum catalyst Karstedt and bis(pinacolato)diboron equivalent to 0.1% of the total mass of the silicone oil. Control the system temperature at 25 °C and stir at a rotation speed of 150 rpm for about 15 min to pre-polymerize the spinning solution to a spinable state, that is, obtain a spinning solution prepolymer.

[0070] S5: Crosslinking and curing into filaments by high-temperature air induction After fully degassing the spinning solution prepolymer prepared in S4, add it to the spinning equipment, pour it into a 50 mL syringe, clamp it on a constant-pressure injection pump, and set the propulsion speed of the constant-pressure injection pump to 0.65 mL·min -1, the actual heating temperature at the center of the heating sleeve was measured to be approximately 200 °C to 220 °C. When the spinning solution prepolymer passed through the heating sleeve at a constant speed, stretching and traction were carried out while in-situ crosslinking and curing were formed, and it was completely cured and formed when entering the rotating collection cage, obtaining a reversible thermochromic antibacterial silicone fiber product. The tensile strength of the silicone fiber prepared in this example was 0.89 cN·tex measured by a double-arm material testing machine -1 .

[0071] Example 10: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 20 min, a rotation speed of 200 rpm, and a ball-to-material ratio of 1.4:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 100nm - 1.5μm. The tensile strength of the silicone fiber prepared in this example was 0.44 cN·tex measured by a double-arm material testing machine -1 .

[0072] Example 11: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 20 min, a rotation speed of 400 rpm, and a ball-to-material ratio of 2.7:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 100nm - 950nm. The tensile strength of the silicone fiber prepared in this example was 0.67 cN·tex measured by a double-arm material testing machine -1 .

[0073] Example 12: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 40 min, a rotation speed of 200 rpm, and a ball-to-material ratio of 3.3:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 140nm - 950nm. The tensile strength of the silicone fiber prepared in this example was 0.63 cN·tex measured by a double-arm material testing machine -1 .

[0074] Example 13: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 40 min, a rotation speed of 400 rpm, and a ball-to-material ratio of 3.0:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 120nm - 700nm. The tensile strength of the silicone fiber prepared in this example was 0.83 cN·tex measured by a double-arm material testing machine -1 .

[0075] Example 14: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 40 min, a rotation speed of 600 rpm, and a ball-to-material ratio of 1.9:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 100 nm to 750 nm. The tensile strength of the silicone fiber prepared in this example was measured to be 0.71 cN·tex by a double-arm material testing machine -1 .

[0076] Example 15: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 60 min, a rotation speed of 200 rpm, and a ball-to-material ratio of 3.6:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 120 nm to 650 nm. The tensile strength of the silicone fiber prepared in this example was measured to be 0.81 cN·tex by a double-arm material testing machine -1 .

[0077] Example 16: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 60 min, a rotation speed of 400 rpm, and a ball-to-material ratio of 2.5:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 120 nm to 630 nm. The tensile strength of the silicone fiber prepared in this example was measured to be 0.82 cN·tex by a double-arm material testing machine -1 .

[0078] Example 17: Referring to Example 9, the ball milling parameters in S1 were adjusted to a time of 60 min, a rotation speed of 600 rpm, and a ball-to-material ratio of 2.2:1. Other conditions and operation steps were the same as those in Example 9. After ball milling, the particle size range of TiO2@AgI was measured to be 100 nm to 630 nm. The tensile strength of the silicone fiber prepared in this example was measured to be 0.81 cN·tex by a double-arm material testing machine -1 .

[0079] The tensile strength of the silicone fiber prepared in the above examples is as Figure 12 shown. As can be seen from (a), the silicone fiber obtained under Example 9 has the most excellent tensile strength, which is 0.89 cN·tex -1 , while the tensile strength of the silicone fiber obtained in the remaining examples is lower than the above value. Combining the particle size distribution analysis, the particle distribution in the remaining examples is uneven, and in some cases, there are particles larger than 2.3 μm, such as Figure 12As shown in (c). The average diameter of the silicone fiber is about 300 μm. Larger particles occupy most of the fiber cross-section, inevitably causing uneven distribution of molecular chains therein. Consequently, under the action of external force, stress concentrates on the larger particles, leading to fiber fracture. In contrast, as Figure 12 shown in (b), the particle size distribution in Example 9 is more uniform, and the particle size mainly concentrates at 326 nm. In this case, the influence of particles on the distribution of molecular chains in the fiber is smaller, and the fiber also maintains satisfactory results when subjected to external tension. In addition, the analysis can also conclude that the ball milling speed has the greatest influence on the particle size and distribution of TiO2@AgI, followed by the ball milling time. On the contrary, the ball-to-powder ratio has the least influence on it. The optimal ball milling process obtained is as follows: time 60 min, speed 600 rpm, and ball-to-powder ratio 4.1:1. Under this optimal scheme, the average strength of the silicone fiber reaches 0.90 cN·tex -1 or more.

[0080] In the present invention, the influence of the addition amount of TiO2@AgI (11:1) on the fiber properties is analyzed through the following examples.

[0081] Example 18: This example provides a reversible thermochromic antibacterial silicone fiber, and its preparation method includes the following steps: S1: Synthesis of TiO2@AgI powder Take a clean container and weigh 11 g of TiO2, then add 500 mL of deionized water and stir at a stirring rate of 1000 rpm for 10 min to fully disperse TiO2; weigh 0.80 g of AgNO3 and pour it into the above-mentioned deionized water and stir at a speed of 1000 rpm for 10 min to fully dissolve it; take another clean container, weigh 0.78 g of KI, add 10 mL of deionized water and dissolve it by ultrasound, then pour it into the above-mentioned AgNO3 solution, and react in the dark for 30 min; perform suction filtration and drying on the obtained TiO2@AgI dispersion. Use a ball mill to mill the sample, with a ball milling time of 60 min, a speed of 600 rpm, and a ball-to-powder ratio of 4.1:1.

[0082] S2: Preparation of silicone oil spinning solution Take a clean container, and successively add 32.5 g of α,ω-vinyl polymethylphenylsiloxane (1000 cp), 4.8 g of α,ω-vinyl poly(methylphenylsiloxane-methylvinylsiloxane) (5000 cp), and 2.7 g of α,ω-dimethylpolymethylhydrogensiloxane (hydrogen content 0.75%), and mix the silicone oil evenly at a stirring rate of 150 rpm to obtain a silicone oil spinning solution.

[0083] S3: Add TiO2@AgI into the silicone oil spinning solution Add 0.8 g (2% of the mass of the silicone oil spinning solution) of the TiO2@AgI prepared in S1 into the silicone oil spinning solution prepared in S2, and stir at a stirring rate of 2000 rpm for 6 h to fully disperse the TiO2@AgI into the silicone oil spinning solution.

[0084] S4: Prepolymerization Add ethynylcyclohexanol (5000 ppm), which is an inhibitor equivalent to 0.1% of the total mass of the silicone oil, into the silicone oil spinning solution obtained in S3, and stir for 5 min to ensure uniform distribution of the inhibitor in the spinning solution; then add 3000 ppm of platinum catalyst Karstedt and bis(pinacolato)diboron equivalent to 0.1% of the total mass of the silicone oil, control the system temperature at 25 °C, and stir at a speed of 150 rpm for about 15 min to prepolymerize the spinning solution to a spinnable state, that is, obtain the prepolymer of the spinning solution.

[0085] S5: Cross-linking and curing into filaments by high-temperature air induction After fully degassing the prepolymer of the spinning solution prepared in S4, add it into the spinning equipment, pour it into a 50 mL syringe, clamp it on a constant-pressure injection pump, and set the advancing speed of the constant-pressure injection pump to 0.65 mL·min -1 , and measure that the actual heating temperature at the center of the heating sleeve is about 200 °C - 220 °C. When the prepolymer of the spinning solution passes through the heating sleeve at a constant speed, it is stretched and drawn while cross-linking and curing in situ, and is completely cured and formed when entering the rotating collection cage, obtaining a reversible thermochromic antibacterial silicone fiber product, code-named TiO2@AgI (11:1) @SiF-2-1. The tensile strength of the silicone fiber prepared in this example is measured to be 0.92 cN·tex by a two-arm material testing machine -1 .

[0086] Place the reversible thermochromic antibacterial silicone fiber TiO2@AgI (11:1) @SiF-2-1 prepared in Example 18 quickly on a heating table at a temperature of 170 °C. Its low thermal conductivity causes its temperature to rise rapidly Figure 13 For the macroscopic color change and infrared thermal imaging of this process, it can be seen from the figure that the fiber is initially white. After heating for 9 s, the temperature of the fiber reaches 125 °C, indicating that the heating speed is very fast, and at this time the color of the fiber has not changed; after heating for 13 s, the temperature of the fiber reaches 145 °C and presents a light yellow color, which is consistent with the previously measured color change temperature; after heating for another 21 s, the fiber completely turns into bright yellow. It only takes about 9 s - 13 s for the fiber to reach the color change temperature from room temperature, and it can quickly respond to the color change when contacting with high-temperature equipment.

[0087] The reversible thermochromic antibacterial organosilicon fiber TiO2@AgI prepared in this example (11:1) @SiF-2-1 has a color change sensitivity as Figure 14 shown. Through infrared thermal imaging, it is shown that when the temperature of the fiber is lower than 134 °C, it appears milky white, and when the temperature reaches 135 °C - 136 °C, it gradually turns bright yellow; in three tests, the error of the color change temperature remains within 1 °C, which indicates that TiO2@AgI (11:1) @SiF-2-1 has color change sensitivity and can respond quickly and accurately to abnormal heat sources.

[0088] Example 19: Referring to Example 18, adjust the addition amount of TiO2@AgI in S3 to 0.2 g (0.5% of the mass of the spinning solution), and the other conditions and operation steps are the same as those in Example 18. The sample code is TiO2@AgI (11:1) @SiF-0.5. The tensile strength of the organosilicon fiber prepared in this example was measured by a double-arm material testing machine to be 1.03 cN·tex -1 , the color difference before and after thermochromism was 8.68, and the antibacterial rate was 90.89%.

[0089] Example 20: Referring to Example 18, adjust the addition amount of TiO2@AgI in S3 to 0.4 g (1.0% of the mass of the spinning solution), and the other conditions and operation steps are the same as those in Example 18. The sample code is TiO2@AgI (11:1) @SiF-1. The tensile strength of the organosilicon fiber prepared in this example was measured by a double-arm material testing machine to be 1.01 cN·tex -1 , the color difference before and after thermochromism was 14.36, and the antibacterial rate was 94.36%.

[0090] Example 21: Referring to Example 18, adjust the addition amount of TiO2@AgI in S3 to 0.6 g (1.5% of the mass of the spinning solution), and the other conditions and operation steps are the same as those in Example 18. The sample code is TiO2@AgI (11:1) @SiF-1.5. The tensile strength of the organosilicon fiber prepared in this example was measured by a double-arm material testing machine to be 0.99 cN·tex -1 , the color difference before and after thermochromism was 18.28, and the antibacterial rate was 98.28%.

[0091] Example 22: Referring to Example 18, adjust the addition amount of TiO2@AgI in S3 to 1.0 g (2.5% of the mass of the spinning solution), and the other conditions and operation steps are the same as those in Example 18. The sample code is TiO2@AgI(11:1) @SiF-2.5. The tensile strength of the silicone fiber prepared in this example was 0.88 cN·tex as measured by a double-arm material testing machine -1 , the color difference before and after thermochromism was 24.98, and the antibacterial rate was 99.99%.

[0092] Example 23: Referring to Example 18, the addition amount of TiO2@AgI in S3 was adjusted to 1.2 g (3.0% of the mass of the spinning solution), and other conditions and operation steps were the same as those in Example 18. The sample code was TiO2@AgI (11:1) @SiF-3. The tensile strength of the silicone fiber prepared in this example was 0.83 cN·tex as measured by a double-arm material testing machine -1 , the color difference before and after thermochromism was 25.77, and the antibacterial rate was 99.99%.

[0093] Example 24: Referring to Example 18, the addition amount of TiO2@AgI in S3 was adjusted to 1.4 g (3.5% of the mass of the spinning solution), and other conditions and operation steps were the same as those in Example 18. The sample code was TiO2@AgI (11:1) @SiF-3.5. The tensile strength of the silicone fiber prepared in this example was 0.82 cN·tex as measured by a double-arm material testing machine -1 , the color difference before and after thermochromism was 23.34, and the antibacterial rate was 99.99%.

[0094] Example 25: Referring to Example 18, the addition amount of TiO2@AgI in S3 was adjusted to 1.6 g (4.0% of the mass of the spinning solution), and other conditions and operation steps were the same as those in Example 18. The sample code was TiO2@AgI (11:1) @SiF-4. The tensile strength of the silicone fiber prepared in this example was 0.74 cN·tex as measured by a double-arm material testing machine -1 , the color difference before and after thermochromism was 23.36, and the antibacterial rate was 99.99%.

[0095] Example 26: Referring to Example 18, the addition amount of TiO2@AgI in S3 was adjusted to 1.8 g (4.5% of the mass of the spinning solution), and other conditions and operation steps were the same as those in Example 18. The sample code was TiO2@AgI (11:1) @SiF-4.5. The tensile strength of the silicone fiber prepared in this example was 0.72 cN·tex as measured by a double-arm material testing machine -1, the color difference before and after thermochromism is 24.53, and the antibacterial rate is 99.99%.

[0096] From Figure 15 (a) It is analyzed that as the relative addition amount of TiO2@AgI (11:1) increases, the number of particles per unit area of the fiber cross-section increases, and the molecular chain distribution decreases, thereby reducing the tensile strength of the fiber. The linear fitting result shows that there is a negative linear correlation between the addition amount and the tensile strength (R 2 = 0.9661). In addition, most of the measurement results are within the 95% confidence interval, indicating that the test results are accurate. Figure 15 (b) shows the stress-strain curve of the fiber after adding 2 wt% TiO2@AgI (11:1) . Before the elongation reaches 25 mm, only a small part of the silicone macromolecules are stretched and oriented under the action of external force. During this period, the tensile strength of the fiber does not change significantly, and the initial modulus of the fiber is low. When the fiber is stretched more than 25 mm, due to the limitation of cross-linking, most of the molecular chains are not easily stretched and instead bear the load together. Therefore, the modulus of the fiber increases sharply, and the fiber breaks under the action of external force. After calculation, the average tensile strength of TiO2@AgI (11:1) @SiF-2-1 is about 0.92 cN·tex -1 (about 9.89 MPa - 11.33 MPa), and the work of fracture is 11.53 N·mm. Figure 15 (c) shows the results of the cyclic tensile test with a tensile elongation rate of 100% for TiO2@AgI (11:1) @SiF-2. After 150 tensile cycles, the tensile strength of the fiber remains stable and there is no stress relaxation phenomenon, indicating that TiO2@AgI (11:1) @SiF-2-1 has excellent resilience and fatigue resistance, so it can be used in extreme environments.

[0097] In addition, the relative addition amount of TiO2@AgI (11:1) will affect the color intensity of the fiber after color change. Figure 16 (a) shows the comparison chart of the fiber before and after color change with different TiO2@AgI (11:1) contents. The color difference value increases with the increase of the TiO2@AgI (11:1) content; while Figure 16 (b) shows that when adding 2 wt% of TiO2@AgI (11:1) , TiO2@AgI (11:1) @SiF-2-1 is white at 20 °C and bright yellow at 150 °C, and the color difference reaches 25.72. When adding 3 wt% of TiO2@AgI (11:1)When the color difference reaches the maximum value (25.77), which is very little different from that at 2 wt%, because the addition of TiO2@AgI (11:1) to the fiber surface layer is almost saturated, and increasing the addition amount will not significantly improve the color difference value of TiO2@AgI (11:1) @SiF-2-1.

[0098] In summary, in the present invention, divinyl-terminated phenyl silicone oil (vinyl-terminated silicone oil) and terminal-side multi-vinyl phenyl silicone oil (side vinyl silicone oil) are used as the main structure of the fiber, hydrogen-containing silicone oil (hydrogen-based silicone oil) is used as the cross-linking agent, and TiO2@AgI is used as the inorganic thermochromic antibacterial powder. After blending the silicone oil, a reversible thermochromic antibacterial silicone fiber is successfully prepared by the method of cross-linking and curing induced by high-temperature air. The aim is to prepare a functional fiber material with high-temperature color change, antibacterial non-toxicity and excellent mechanical properties. Through the characterization of the instrument and various performance tests, the silicone fiber has the following characteristics: First, it is observed under SEM and ultra-depth-of-field three-dimensional microscope that the longitudinal surface of TSiF is smooth and the cross-section is uniform in thickness. Combining with EDS analysis, it is concluded that TSiF is mainly composed of six elements: Si, O, C, Ti, Ag, and I; all of these can indicate the successful preparation of the reversible thermochromic antibacterial silicone fiber; By adjusting the mass ratio of TiO2 and AgI, the color change performance and antibacterial performance of TiO2@AgI can be adjusted. It is found that when the mass ratio of TiO2 to AgI is 11:1, TiO2@AgI (11:1) @SiF-2 can obtain the best comprehensive performance of color change performance and antibacterial efficacy. It is measured that the color difference of TiO2@AgI (11:1) @SiF-2 before and after thermochromism is 25.72, and the antibacterial rate is as high as 99.99%. After the extraction solution of TiO2@AgI with different concentrations is co-cultured with L929 cells for 12 h, the cell survival rate still remains above 98%. (11:1)

[0099] Secondly, a ball mill is used to ball mill the prepared TiO2@AgI to explore the influence of the particle size and distribution of TiO2@AgI on the mechanical properties of the fiber. The addition amount is set to 2% of the mass of the spinning solution; by comparison, it is found that under the condition that other parameters are fixed, when the ball milling parameters are time 20 min, rotation speed 600 rpm, and ball-to-material ratio 4.1:1, the particle size distribution of TiO2@AgI is uniform, and the tensile strength of the fiber prepared at this time reaches the best, about 0.89 cN·tex -1 , and the optimal ball milling parameters are explored as time 60 min, rotation speed 600 rpm, and ball-to-material ratio 4.1:1. At this time, the tensile strength of the fiber prepared is further improved, about 0.92 cN·tex -1 ​(about 9.89 MPa to 11.33 MPa).

[0100] Finally, the comprehensive effects of the addition amount of TiO2@AgI on the tensile strength, color-changing performance and antibacterial performance of the fiber were studied. The addition amount of TiO2@AgI was 0.5% - 4.5% of the mass of the spinning solution. When the addition amount was 2.0% of the mass of the spinning solution, the prepared TiO2@AgI (11:1) @SiF-2 color difference was close to the maximum value, and it had the functions of quickly changing color when contacting a high-temperature heat source and excellent color-changing sensitivity, and the antibacterial rate reached the maximum value. At this time, the tensile strength was also relatively high. After 150 cycles of 100% stretching, the tensile strength remained unchanged.

[0101] The reversible thermochromic antibacterial organosilicon fiber prepared by the present invention not only has the characteristics of high-temperature reversible thermochromism, fast response, but also has the characteristics of antibacterial and non-toxicity. At the same time, it has excellent tensile strength, and the preparation process is more simple and the cost is low, which is suitable for industrial production.

[0102] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Without departing from the scope and technical principles of the described embodiments, many modifications and changes are obvious to those of ordinary skill in the art. These modifications and changes should also be regarded as the protection scope of the present invention.

Claims

1. An inorganic composite powder, characterized in that, The inorganic composite powder is TiO2@AgI, where AgI is dispersed and loaded on the TiO2 substrate in a nano form, and the mass ratio of AgI to TiO2 is 1:(1 - 50); the particle size of the TiO2@AgI is 100 nm to 5 μm.

2. The inorganic composite powder material according to claim 1, wherein In the TiO2@AgI, the mass ratio of AgI to TiO2 is 1:(10 - 11), and the particle size of the TiO2@AgI is 100 nm to 500 nm.

3. The inorganic composite powder material according to claim 2, characterized in that, The TiO2 is in the rutile phase, anatase phase or a mixture of the two phases.

4. A method for preparing the inorganic composite powder material according to any one of claims 1 to 3, characterized in that, It includes: Mix TiO2, KI and AgNO3 in deionized water, and prepare TiO2@AgI powder by the dissolution-precipitation method; Among them, the mass ratio of TiO2, KI and AgNO3 is 1:(0.95 - 1.05):(5 - 50), and the reaction time of the dissolution-precipitation method is 5 min to 120 min.

5. The preparation method of the inorganic composite powder material according to claim 4, characterized in that, The mass ratio of TiO2, KI and AgNO3 is 1:(0.98 - 1.02):(10 - 15), and the reaction time is 5 min to 60 min.

6. The preparation method of the inorganic composite powder material according to claim 4, characterized in that, It also includes: After the dissolution-precipitation method reaction is completed, the obtained product is ball-milled by a ball-milling device.

7. The preparation method of the inorganic composite powder material according to claim 6, characterized in that, The ball-milling parameters include: the ball-milling time is 20 min to 60 min, the rotation speed is 200 rpm to 600 rpm, and the ball-to-material ratio is (1.4 - 4.1):

1.

8. A reversible thermochromic antibacterial silicone fiber, characterized in that, The raw materials of the silicone fiber include silicone oil spinning solution, the TiO2@AgI powder according to any one of claims 1 to 3, a catalyst, an inhibitor and a curing accelerator; the silicone oil spinning solution includes vinyl silicone oil and hydrogen silicone oil with a mass ratio of 1:(0.8 - 1.4), the vinyl silicone oil includes terminal vinyl silicone oil and side vinyl silicone oil, and the addition amount of side vinyl silicone oil in the vinyl silicone oil is 0 - 20 wt%; the addition amount of the TiO2@AgI powder material is 0.5 wt% - 4.5 wt% of the total amount of the silicone oil spinning solution; the addition amounts of the catalyst, inhibitor and curing accelerator are each 0.1 wt% - 1 wt% of the total amount of the silicone oil spinning solution.

9. The reversible thermochromic antibacterial silicone fiber according to claim 8, wherein, The mass ratio of the vinyl silicone oil to the hydrogen silicone oil is 1:(1.1 - 1.2), the addition amount of side vinyl silicone oil in the vinyl silicone oil is 14 wt% - 16 wt%, and the addition amount of the TiO2@AgI is 1 wt% - 5 wt% of the total amount of the silicone oil.

10. A method for preparing the reversible thermochromic antibacterial silicone fiber according to claim 8, characterized in that, It includes: Mix TiO2, KI and AgNO3 in deionized water, and prepare TiO2@AgI powder material by the dissolution-precipitation method; Mix the vinyl silicone oil and the hydrogen silicone oil evenly in proportion to prepare a silicone oil spinning solution; Add the TiO2@AgI powder material to the silicone oil spinning solution and disperse it evenly; Add a catalyst, an inhibitor and a curing accelerator to the silicone oil spinning solution added with the TiO2@AgI powder material, and stir to obtain a spinning solution prepolymer; Add the above spinning solution prepolymer to a spinning device, and spin and prepare it by air heating-induced crosslinking and curing.

11. The preparation method of the reversible thermochromic antibacterial silicone fiber according to claim 10, characterized in that, It also includes: After the dissolution-precipitation method reaction is completed, the obtained product is ball-milled by a ball-milling device.

12. Use of the reversible thermochromic antibacterial silicone fiber according to claim 8 in the preparation of a reversible thermochromic material.

13. Use of the reversible thermochromic antibacterial silicone fiber according to claim 8 in the preparation of an antibacterial material.

Images