Preparation method of antibacterial and flame-retardant chitosan film with infrared stealth function

Abstract

The preparation method comprises the following steps: S1, adding a certain amount of tin-doped indium oxide and carbon nanotubes into an aqueous solution containing aniline and hydrochloric acid, carrying out ultrasonic dispersion for 1-2 hours, then adding ammonium persulfate, and carrying out a reaction for a certain time, so as to obtain a solution A; centrifuging, washing and drying to obtain polyaniline modified carbon nanotubes and tin-doped indium oxide particles; s2, mixing polyaniline modified tin-doped indium oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water, mechanically stirring and uniformly dispersing, then performing ultrasonic treatment to remove bubbles, pouring a film forming solution into a polytetrafluoroethylene mold for tape casting, and then putting the film forming solution into a drying oven for treatment to obtain the antibacterial flame-retardant infrared stealth functional chitosan film. According to the invention, by means of the synergistic effect among the carbon nanotubes, the tin-doped indium oxide, the polyaniline and the chitosan, the chitosan film has extremely low infrared emissivity, and a good infrared stealth effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of chitosan membrane preparation technology, specifically a method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane. Background Technology

[0002] Detection and guidance technologies on the modern battlefield have become increasingly diversified. The rapid development of infrared detection technology, in particular, has posed a serious threat to the survival and safety of soldiers and other military targets. Infrared stealth technology, as an effective means of enhancing the survivability and combat effectiveness of military defense systems, has become a key area of ​​research for many countries. The development of infrared stealth technology primarily relies on the development of infrared stealth materials and their organic integration with substrates. This aims to minimize the difference in infrared radiation between military targets in the 8-14μm band and their background, preventing infrared detectors from receiving sufficient thermal energy, reducing the probability of detection and tracking, and enhancing penetration and strike capabilities.

[0003] Inorganic low-emissivity materials, characterized by low cost, large storage capacity, and excellent low-emissivity performance, occupy an important position in the field of infrared stealth. Inorganic semiconductor materials are doped materials that fall between conductors and insulators. By altering the carrier mobility, carrier density, and carrier collision frequency of semiconductor materials with dopants, they exhibit low infrared absorption in the infrared band. Indium tin oxide (ITO) semiconductor materials often achieve infrared stealth effects by forming thin films. However, current semiconductor thin film technology involves complex processes, is difficult to handle on complex surfaces, and is costly. A combination of ultrasonic and physical dispersion was used to prepare an ITO-phenolic resin nanocoating, but the resulting coating had a high infrared emissivity, failing to meet the requirements for low infrared emissivity.

[0004] Chitosan is a naturally occurring polysaccharide that can be extracted from the shells of shrimp, crabs, and other organisms. It possesses antibacterial properties, load-bearing capacity, film-forming properties, and biocompatibility. Using chitosan to prepare infrared stealth films offers significant advantages. Using chitosan, Cd(Ac)₂, and H₂S(g) as raw materials, a one-step method was used at room temperature to introduce H₂S(g) into a chitosan-Cd(Ac)₂ composite membrane, resulting in a chitosan-based cadmium sulfide (CdS) nanoparticle composite membrane. The prepared composite membrane exhibits low infrared emissivity. However, cadmium sulfide is highly toxic and is listed as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization.

[0005] Using indium tin oxide (ITO) as a low-emissivity material to dope chitosan and develop antibacterial infrared stealth films is of great significance for improving the safety protection performance of military personnel. However, the compatibility between ITO particles and chitosan films is poor, and they cannot be uniformly dispersed in the chitosan films. Furthermore, the infrared emissivity of ITO alone is still insufficient to meet practical requirements. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane to solve the problems in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane, comprising the following steps:

[0008] S1. A certain amount of tin-doped indium oxide and carbon nanotubes are added to an aqueous solution containing aniline and hydrochloric acid, ultrasonically dispersed for 1-2 hours, and then ammonium persulfate is added and reacted for a certain time. After centrifugation, washing and drying, polyaniline-modified carbon nanotubes and tin-doped indium oxide particles are obtained.

[0009] S2. Polyaniline-modified indium tin oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water are mixed and dispersed evenly by mechanical stirring. Then, ultrasonic treatment is performed to remove air bubbles. The film-forming solution is poured into a polytetrafluoroethylene mold for casting and then placed in an oven for treatment to obtain an antibacterial, flame-retardant and infrared stealth chitosan film.

[0010] Preferably, in S1, the carbon nanotube content accounts for 10-20% of the sum of the carbon nanotube content and the indium tin oxide content; the ratio of the sum of the carbon nanotube content and the indium tin oxide content to the aniline content is 3-7:1.

[0011] Preferably, the molar ratio of aniline to hydrochloric acid in S1 is 15-20:1, and the molar ratio of aniline to ammonium persulfate is 1:1-1.2.

[0012] Preferably, the in-situ modification of polyaniline in S1 is carried out at room temperature for 3-5 hours; the modified product is washed with ethanol and distilled water 1-3 times respectively.

[0013] Preferably, in S2, the chitosan has a molecular weight of 50-200 kDa, the amount of chitosan used accounts for 5-7% of the distilled water, and the amount of acetic acid used is 1-2%.

[0014] Preferably, the amount of citric acid used in S2 is 0.5-1.5%.

[0015] Preferably, in step S2, the amount of chitosan used accounts for 5-7% of the distilled water, and the amount of acetic acid used is 1-2%.

[0016] Preferably, the temperature at which the functional chitosan forms a film in S2 is 30-60°C.

[0017] Preferably, the sum of the amount of modified carbon nanotubes and the amount of indium tin oxide particles added in S2 is 10-20% of the amount of chitosan added.

[0018] Preferably, the thickness of the chitosan membrane prepared in step S2 is 20-60 μm.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The chitosan used in this invention has good biocompatibility, abundant raw material sources, and low toxicity. The antibacterial, flame-retardant, infrared stealth film prepared is an environmentally friendly functional film.

[0021] 2. The carbon nanotubes modified in situ with polyaniline and the indium tin-doped oxide of the present invention have good compatibility with chitosan films and are uniformly dispersed in chitosan films. The mechanical properties of the obtained chitosan films are not significantly affected.

[0022] 3. The chitosan film prepared by this invention is an organic-inorganic composite material. With the help of the synergistic effect between carbon nanotubes, indium tin oxide, polyaniline and chitosan components, the chitosan film has an extremely low infrared emissivity, which can achieve a good infrared stealth effect. At the same time, the functional chitosan film has excellent antibacterial and flame retardant properties and has broad application prospects. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a flowchart of the present invention;

[0025] Figure 2 These are infrared stealth effect images of the modified and unmodified chitosan films of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0027] Please see Figure 1-2 In this embodiment of the invention, a method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan film includes the following steps:

[0028] Implementation Case 1

[0029] S1. A certain amount of tin-doped indium oxide and carbon nanotubes were added to an aqueous solution containing aniline and hydrochloric acid, ultrasonically dispersed for 1.5 h, and then ammonium persulfate was added and reacted for a certain time. After centrifugation, washing and drying, polyaniline-modified carbon nanotubes and tin-doped indium oxide particles were obtained.

[0030] S2. Polyaniline-modified indium tin oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water are mixed and dispersed evenly by mechanical stirring. Then, ultrasonic treatment is performed to remove air bubbles. The film-forming solution is poured into a polytetrafluoroethylene mold for casting and then placed in an oven for treatment to obtain an antibacterial, flame-retardant and infrared stealth chitosan film.

[0031] In S1, the carbon nanotube content accounts for 17% of the sum of the carbon nanotube content and the indium tin oxide content. The carbon nanotubes and indium tin oxide achieve infrared stealth function through synergistic effect. The ratio of the sum of the carbon nanotube content and the indium tin oxide content to the aniline content is 5:1. If the aniline content is too low, it will not be conducive to the surface modification of carbon nanotubes and indium tin oxide. If the content is too high, it will be wasteful.

[0032] In S1, the molar ratio of aniline to hydrochloric acid is 18:1, the molar ratio of aniline to ammonium persulfate is 1:1.1, hydrochloric acid is a polyaniline dopant, and ammonium persulfate is a catalyst.

[0033] The in-situ modification of polyaniline in S1 involves reacting at room temperature for 4 hours. If the reaction time is too short, the modification will be incomplete; if the reaction time is too long, it will be wasteful. Within the provided time range, polyaniline can be generated on the surface of carbon nanotubes and indium tin oxide. Surface modification of polyaniline can improve the conductivity and infrared reflectivity of the material, thereby playing a synergistic role with carbon nanotubes and indium tin oxide to improve the infrared stealth function of the chitosan film. The modified product is washed twice with ethanol and distilled water respectively to remove unreacted acid and catalyst.

[0034] In S2, the chitosan has a molecular weight of 150 kDa, the amount of chitosan used accounts for 6% of the distilled water, and the amount of acetic acid used is 1.7%. Chitosan is soluble in acidic solutions. Too little acetic acid is not conducive to the dissolution of chitosan, while too much acetic acid is wasteful.

[0035] The amount of citric acid in S2 is 1.3%. Citric acid plays a dual role: firstly, it provides acidic conditions, and secondly, it plays a cross-linking role in the chitosan film formation process, grafting modified carbon nanotubes and indium tin oxide particles onto the chitosan film. If the amount of citric acid is too low, it will not achieve a good cross-linking effect, and if the amount is too high, it will affect the film-forming properties of chitosan.

[0036] The film-forming temperature of the functional chitosan in S2 is 50°C.

[0037] The total amount of modified carbon nanotubes and indium tin oxide particles added in S2 is 16% in chitosan.

[0038] The thickness of the chitosan membrane prepared in S2 is 40 μm.

[0039] The chitosan membrane of this invention has an infrared emissivity of 0.13 in the 8-14 μm band (the infrared emissivity of chitosan membrane alone is 0.73); the antibacterial rate against Escherichia coli and Staphylococcus aureus is 99.9%, and the limiting oxygen index is increased to 38% (the limiting oxygen index of chitosan membrane alone is 25%).

[0040] Implementation Case 2

[0041] S1. A certain amount of tin-doped indium oxide and carbon nanotubes were added to an aqueous solution containing aniline and hydrochloric acid, ultrasonically dispersed for 1.3 hours, and then ammonium persulfate was added and reacted for a certain period of time. After centrifugation, washing and drying, polyaniline-modified carbon nanotubes and tin-doped indium oxide particles were obtained.

[0042] S2. Polyaniline-modified indium tin oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water are mixed and dispersed evenly by mechanical stirring. Then, ultrasonic treatment is performed to remove air bubbles. The film-forming solution is poured into a polytetrafluoroethylene mold for casting and then placed in an oven for treatment to obtain an antibacterial, flame-retardant and infrared stealth chitosan film.

[0043] In S1, the carbon nanotube content accounts for 15% of the sum of the carbon nanotube content and the indium tin oxide content. The carbon nanotubes and indium tin oxide achieve infrared stealth function through synergistic effect. The ratio of the sum of the carbon nanotube content and the indium tin oxide content to the aniline content is 4:1. If the aniline content is too low, it will not be conducive to the surface modification of carbon nanotubes and indium tin oxide. If the content is too high, it will be wasteful.

[0044] In S1, the molar ratio of aniline to hydrochloric acid is 16:1, the molar ratio of aniline to ammonium persulfate is 1:1, hydrochloric acid is a polyaniline dopant, and ammonium persulfate is a catalyst.

[0045] The in-situ modification of polyaniline in S1 involves reacting at room temperature for 3.5 hours. If the reaction time is too short, the modification will be incomplete; if the reaction time is too long, it will be wasteful. Within the provided time range, polyaniline can be generated on the surface of carbon nanotubes and indium tin oxide. Surface modification of polyaniline can improve the conductivity and infrared reflectivity of the material, thereby playing a synergistic role with carbon nanotubes and indium tin oxide to improve the infrared stealth function of the chitosan film. The modified product is washed once with ethanol and once with distilled water to remove unreacted acid and catalyst.

[0046] In S2, the chitosan has a molecular weight of 100 kDa, the amount of chitosan used accounts for 5.5% of the distilled water, and the amount of acetic acid used is 1.4%. Chitosan dissolves in acidic solutions. Too little acetic acid is not conducive to the dissolution of chitosan, while too much acetic acid is wasteful.

[0047] The amount of citric acid in S2 is 1.0%. Citric acid plays a dual role: firstly, it provides acidic conditions, and secondly, it plays a cross-linking role in the chitosan film formation process, grafting modified carbon nanotubes and tin-doped indium oxide particles onto the chitosan film. If the amount of citric acid is too low, it will not achieve a good cross-linking effect, and if the amount is too high, it will affect the film-forming properties of chitosan.

[0048] The film-forming temperature of the functional chitosan in S2 is 40°C.

[0049] The total amount of modified carbon nanotubes and indium tin oxide particles added in S2 is 13% of the total amount of chitosan added.

[0050] The thickness of the chitosan membrane prepared in S2 is 30 μm.

[0051] The chitosan membrane of this invention has an infrared emissivity of 0.15 in the 8-14 μm band (the infrared emissivity of chitosan membrane alone is 0.73); the antibacterial rate against Escherichia coli and Staphylococcus aureus is 99.9%, and the limiting oxygen index is increased to 36% (the limiting oxygen index of chitosan membrane alone is 25%).

[0052] Implementation Case 3

[0053] S1. A certain amount of tin-doped indium oxide and carbon nanotubes were added to an aqueous solution containing aniline and hydrochloric acid, ultrasonically dispersed for 1 hour, and then ammonium persulfate was added and reacted for a certain time. After centrifugation, washing and drying, polyaniline-modified carbon nanotubes and tin-doped indium oxide particles were obtained.

[0054] S2. Polyaniline-modified indium tin oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water are mixed and dispersed evenly by mechanical stirring. Then, ultrasonic treatment is performed to remove air bubbles. The film-forming solution is poured into a polytetrafluoroethylene mold for casting and then placed in an oven for treatment to obtain an antibacterial, flame-retardant and infrared stealth chitosan film.

[0055] In S1, the carbon nanotube content accounts for 10% of the sum of the carbon nanotube content and the indium tin oxide content. The carbon nanotubes and indium tin oxide achieve infrared stealth function through synergistic effect. The ratio of the sum of the carbon nanotube content and the indium tin oxide content to the aniline content is 3:1. If the aniline content is too low, it will not be conducive to the surface modification of carbon nanotubes and indium tin oxide. If the content is too high, it will be wasteful.

[0056] In S1, the molar ratio of aniline to hydrochloric acid is 15:1, the molar ratio of aniline to ammonium persulfate is 1:1.1, hydrochloric acid is a polyaniline dopant, and ammonium persulfate is a catalyst.

[0057] The in-situ modification of polyaniline in S1 involves reacting at room temperature for 3 hours. If the reaction time is too short, the modification will be incomplete; if the reaction time is too long, it will be wasteful. Within the provided time range, polyaniline can be generated on the surface of carbon nanotubes and indium tin oxide. Surface modification of polyaniline can improve the conductivity and infrared reflectivity of the material, thereby playing a synergistic role with carbon nanotubes and indium tin oxide to improve the infrared stealth function of the chitosan film. The modified product is washed twice with ethanol and distilled water respectively to remove unreacted acid and catalyst.

[0058] In S2, the chitosan has a molecular weight of 50 kDa, the amount of chitosan used accounts for 5% of the distilled water, and the amount of acetic acid used is 1%. Chitosan dissolves in acidic solutions. Too little acetic acid is not conducive to the dissolution of chitosan, while too much acetic acid is wasteful.

[0059] The amount of citric acid in S2 is 0.5%. Citric acid plays a dual role: firstly, it provides acidic conditions, and secondly, it plays a cross-linking role in the chitosan film formation process, grafting modified carbon nanotubes and tin-doped indium oxide particles onto the chitosan film. If the amount of citric acid is too low, it will not achieve a good cross-linking effect, and if the amount is too high, it will affect the film-forming properties of chitosan.

[0060] The film-forming temperature of the functional chitosan in S2 is 30°C.

[0061] The sum of the amount of modified carbon nanotubes and indium tin oxide particles added in S2 is 10% of the total amount added to chitosan.

[0062] The thickness of the chitosan membrane prepared in S2 is 20 μm.

[0063] The chitosan membrane of this invention has an infrared emissivity of 0.18 in the 8-14 μm band (the infrared emissivity of chitosan membrane alone is 0.73); the antibacterial rate against Escherichia coli and Staphylococcus aureus is 99.9%, and the limiting oxygen index is increased to 34% (the limiting oxygen index of chitosan membrane alone is 25%).

[0064] Implementation Case 4

[0065] S1. A certain amount of tin-doped indium oxide and carbon nanotubes were added to an aqueous solution containing aniline and hydrochloric acid, ultrasonically dispersed for 2 hours, and then ammonium persulfate was added and reacted for a certain period of time. After centrifugation, washing and drying, polyaniline-modified carbon nanotubes and tin-doped indium oxide particles were obtained.

[0066] S2. Polyaniline-modified indium tin oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water are mixed and dispersed evenly by mechanical stirring. Then, ultrasonic treatment is performed to remove air bubbles. The film-forming solution is poured into a polytetrafluoroethylene mold for casting and then placed in an oven for treatment to obtain an antibacterial, flame-retardant and infrared stealth chitosan film.

[0067] In S1, the carbon nanotube content accounts for 20% of the sum of the carbon nanotube content and the indium tin oxide content. The carbon nanotubes and indium tin oxide achieve infrared stealth function through synergistic effect. The ratio of the sum of the carbon nanotube content and the indium tin oxide content to the aniline content is 7:1. If the aniline content is too low, it will not be conducive to the surface modification of carbon nanotubes and indium tin oxide. If the content is too high, it will be wasteful.

[0068] In S1, the molar ratio of aniline to hydrochloric acid is 20:1, the molar ratio of aniline to ammonium persulfate is 1:1.2, hydrochloric acid is a polyaniline dopant, and ammonium persulfate is a catalyst.

[0069] The in-situ modification of polyaniline in S1 involves reacting at room temperature for 5 hours. If the reaction time is too short, the modification will be incomplete; if the reaction time is too long, it will be wasteful. Within the provided time range, polyaniline can be generated on the surface of carbon nanotubes and indium tin oxide. Surface modification of polyaniline can improve the conductivity and infrared reflectivity of the material, thereby playing a synergistic role with carbon nanotubes and indium tin oxide to improve the infrared stealth function of the chitosan film. The modified product is washed three times with ethanol and distilled water respectively to remove unreacted acid and catalyst.

[0070] In S2, the chitosan has a molecular weight of 200 kDa, the amount of chitosan used accounts for 7% of the distilled water, and the amount of acetic acid used is 2%. Chitosan is soluble in acidic solutions. Too little acetic acid is not conducive to the dissolution of chitosan, while too much acetic acid is wasteful.

[0071] The amount of citric acid in S2 is 1.5%. Citric acid plays a dual role: firstly, it provides acidic conditions, and secondly, it plays a cross-linking role in the chitosan film formation process, grafting modified carbon nanotubes and tin-doped indium oxide particles onto the chitosan film. If the amount of citric acid is too low, it will not achieve a good cross-linking effect, and if the amount is too high, it will affect the film-forming properties of chitosan.

[0072] The film-forming temperature of the functional chitosan in S2 is 60°C.

[0073] The sum of the amount of modified carbon nanotubes and indium tin oxide particles added in S2 is 20% of the total amount added to chitosan.

[0074] The thickness of the chitosan membrane prepared in S2 is 60 μm.

[0075] The chitosan membrane of this invention has an infrared emissivity of 0.11 in the 8-14 μm band (the infrared emissivity of chitosan membrane alone is 0.73); the antibacterial rate against Escherichia coli and Staphylococcus aureus is 99.9%, and the limiting oxygen index is increased to 39% (the limiting oxygen index of chitosan membrane alone is 25%).

[0076] The inhibition rates of Escherichia coli and Staphylococcus aureus were determined according to GB / T20944.3-2008 "Evaluation of antimicrobial properties of textiles - Part 3: Vibration method";

[0077] Limiting Oxygen Index (LOI): Tested according to GB / T 5454-1997 "Test for Combustion Performance of Textiles - Oxygen Index Method".

[0078] Comparative Case 1: Similar to Implementation Case 1, but without the use of polyaniline to modify the carbon nanotubes and indium tin-doped oxide, the chitosan film exhibited an infrared emissivity of 0.45 in the 8-14 μm band, with an antibacterial rate of 99.9% against both Escherichia coli and Staphylococcus aureus, and a limiting oxygen index of 27.5%. This is because the unmodified carbon nanotubes and indium tin-doped oxide powder had poor dispersion properties in chitosan, resulting in a higher far-infrared emissivity and poor flame retardant properties.

[0079] Comparative Case 2: Similar to Implementation Case 1, but modified with polyaniline, the chitosan film has an infrared emissivity of 0.34 in the 8-14μm band, an antibacterial rate of 99.9% against Escherichia coli and Staphylococcus aureus, and a limiting oxygen index of 27.8%, indicating that the infrared stealth effect of tin-doped indium oxide alone is limited.

[0080] The working principle of this invention is:

[0081] Polyaniline is a high-molecular organic material with good compatibility with chitosan. Polyaniline is used to modify the surface of carbon nanotubes and indium tin oxide particles through in-situ polymerization. Polyaniline is uniformly grafted onto the surface of carbon nanotubes and indium tin oxide particles in situ, so that carbon nanotubes and indium tin oxide particles can have good compatibility with chitosan and can be uniformly dispersed in chitosan film.

[0082] Meanwhile, doped polyaniline has good electrical conductivity and is used for surface modification of carbon nanotubes and indium tin oxide particles. This not only improves the compatibility and dispersibility of carbon nanotubes and indium tin oxide particles in chitosan, but also enables them to work synergistically with carbon nanotubes and indium tin oxide particles to achieve better infrared stealth function.

[0083] Chitosan macromolecules have high molecular bound charge and dipole density, strong electret state and piezoelectric effect, which makes the radial orientation of the dipoles regular, thus giving them good infrared reflectivity. The combination of chitosan-polyaniline-carbon nanotubes and indium tin oxide constitutes an organic-inorganic composite low emissivity material system, which makes the prepared chitosan film have extremely low infrared emissivity and good infrared stealth effect.

[0084] Carbon nanotubes and tin-doped indium oxide particles are inorganic materials. During combustion, they form complex carbon residues that accumulate on the substrate surface, hindering the transfer of heat and oxygen. In addition, polyaniline decomposes upon heating to produce non-flammable nitrogen-containing gases, which dilute the concentration of flammable gases and oxygen in the combustion zone, thus playing a role in the gas phase. Therefore, the flame retardant properties of the functional chitosan film are significantly improved.

[0085] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan film, characterized in that, Includes the following steps: S1. A certain amount of tin-doped indium oxide and carbon nanotubes are added to an aqueous solution containing aniline and hydrochloric acid, ultrasonically dispersed for 1-2 hours, and then ammonium persulfate is added and reacted for a certain time. After centrifugation, washing and drying, polyaniline-modified carbon nanotubes and tin-doped indium oxide particles are obtained. S2. Polyaniline-modified indium tin oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water are mixed and dispersed evenly by mechanical stirring. Then, ultrasonic treatment is performed to remove air bubbles. The film-forming solution is poured into a polytetrafluoroethylene mold for casting and then placed in an oven for treatment to obtain an antibacterial, flame-retardant and infrared stealth chitosan film.

2. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, In S1, the carbon nanotube content accounts for 10-20% of the sum of the carbon nanotube content and the indium tin oxide content; the ratio of the sum of the carbon nanotube content and the indium tin oxide content to the aniline content is 3-7:

1.

3. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1 or 2, characterized in that, The molar ratio of aniline to hydrochloric acid in S1 is 15-20:1, and the molar ratio of aniline to ammonium persulfate is 1:1-1.

2.

4. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, The in-situ modification of polyaniline in S1 is carried out at room temperature for 3-5 hours; the modified product is washed 1-3 times with ethanol and distilled water respectively.

5. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, In S2, the chitosan has a molecular weight of 50-200 kDa, the amount of chitosan used accounts for 5-7% of the distilled water, and the amount of acetic acid used is 1-2%.

6. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, The amount of citric acid used in S2 is 0.5-1.5%.

7. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, In S2, the amount of chitosan used accounts for 5-7% of the distilled water, and the amount of acetic acid used is 1-2%.

8. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, The film-forming temperature of the functional chitosan in S2 is 30-60℃.

9. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan film according to claim 1, characterized in that, The sum of the amount of modified carbon nanotubes and indium tin oxide particles added in S2 is 10-20% of the total amount added to chitosan.

10. The method for preparing an antibacterial, flame-retardant, infrared stealth functional chitosan membrane according to claim 1, characterized in that, The thickness of the chitosan membrane prepared in S2 is 20-60 μm.

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