Aerogel loaded thiophene-based conjugated polymer antibacterial agent and preparation method and application thereof

Abstract

The present application relates to the technical field of photocatalyst preparation, in particular to an aerogel loaded thiophene-based conjugated polymer antibacterial agent and its preparation method and application. The preparation method comprises: using 2,5-bis(trimethylstannyl)thiophene and carboxyl thiophene dibromide as raw materials, coupling reaction is carried out in the presence of catalyst and solvent, and carboxyl modified thiophene-based conjugated polymer is obtained; the straw is sequentially subjected to alkali treatment, oxidation treatment, freeze drying of straw cellulose sol and carbonization treatment, and straw carbon aerogel is obtained; the straw carbon aerogel is immersed in the solution of carboxyl modified thiophene-based conjugated polymer to obtain the aerogel loaded thiophene-based conjugated polymer antibacterial agent. The present application not only overcomes the defects of the existing aerogel composite material loaded polymer antibacterial agent, such as insufficient light absorption rate, difficulty in fully exerting photocatalytic potential and poor long-term use stability, but also solves the problem of high cost of the existing preparation method.

Description

Technical Field

[0001] This invention relates to the field of photocatalyst preparation technology, specifically to an aerogel-supported thiophene-based conjugated polymer antibacterial agent, its preparation method, and its application. Background Technology

[0002] Microbial contamination is a prominent and fundamental cause threatening global public health security. Although the development of antibiotics is an effective way to suppress and kill pathogens, the overuse of antibiotics can lead to significant drug resistance. Photocatalytic antibacterial, as a safer antibacterial method without cytotoxicity or harmful effects, has received increasing attention. The antibacterial principle is that when photocatalytic materials are exposed to light, they generate reactive oxygen species (ROS), which can destroy bacterial cell membranes, proteins, and deoxyribonucleic acid (DNA).

[0003] Currently, antibacterial materials are mainly classified into natural antibacterial materials, composite antibacterial materials, organic antibacterial materials, and inorganic antibacterial materials. Among them, organic photocatalysts avoid metal coordination chemistry, provide greater chemical stability, and exhibit greater solubility in organic solvents. Polythiophene and its derivatives have unique electrical behavior, good environmental stability, low optical band gap, stability in doped or neutral states, and are particularly easy to synthesize, making them promising photocatalytic candidates.

[0004] Chinese patent CN118909301A discloses a high-temperature resistant polyimide aerogel composite material, its preparation method, and its applications. Based on a chemical imidization-supercritical drying method, it innovatively incorporates metal oxide organic precursors or non-metal oxide organic precursors as reinforcing phases and proposes for the first time an effective and feasible unidirectional vacuum impregnation composite method for aerogel and fiber preforms, facilitating the modification and reinforcement of polyimide aerogels. It exhibits excellent high-temperature resistance, strong thermal stability, low density, and high strength. Chinese patent CN117050372A discloses a high-performance thermal insulation material, specifically involving a shrinkage-resistant fiber-reinforced polyimide aerogel composite material. The fiber-reinforced PI aerogel composite material prepared by it exhibits outstanding high-temperature resistance and high mechanical properties; furthermore, due to the fiber reinforcement, the shrinkage problem of the aerogel during the preparation process is greatly improved. Chinese patent CN108727818A discloses a silica / polyimide aerogel composite material, comprising hydrophobically modified silica aerogel and polyimide aerogel, which improves the mechanical strength of the composite thermal insulation material. The silica aerogel serves as a filler, possessing not only hydrophobic properties but also excellent thermal insulation performance, playing a crucial role in the composite material. It combines the advantages of high strength, high temperature resistance, low density, low thermal conductivity, and good waterproof performance, meeting the performance requirements of thermal insulation materials in practical applications. Chinese patent CN113861682A discloses a more environmentally friendly and convenient preparation method and performance testing of a low-density hydrophobic polyimide aerogel material. This material features hydrophobicity, compatibility with various molding and casting processes, a simple preparation process, and significantly reduced organic matter volatilization during preparation. The material is internally porous with a density of less than 0.1 g / cm³. 3 The water contact angle on the aerogel surface can reach over 120°, exhibiting excellent thermal properties. It has significant application potential in heat insulation, catalysis, organic matter adsorption, and air filtration.

[0005] Currently, the aerogel composite materials for supporting polymer antibacterial agents prepared by existing methods have insufficient light absorption due to their wide band gap, making it difficult to fully realize their photocatalytic potential. Furthermore, their relatively high preparation cost limits their potential for large-scale application. In addition, existing aerogel composite materials for supporting polymer antibacterial agents exhibit poor stability during long-term use, a deficiency that severely restricts their practical production and application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an aerogel-supported thiophene-based conjugated polymer antibacterial agent, its preparation method, and its application. This invention uses straw as raw material, successively treating it with alkali and oxidation to obtain straw cellulose; then, the straw cellulose is processed by a sol-freeze-drying method to obtain a porous straw cellulose aerogel, which is then carbonized to obtain a straw carbon aerogel; finally, the straw carbon aerogel is impregnated in a solution of carboxyl-modified thiophene-based conjugated polymer and dried to obtain the aerogel-supported thiophene-based conjugated polymer antibacterial agent. This invention utilizes hydrogen bonding to load a carboxyl-modified thiophene-based conjugated polymer with narrow band gap characteristics onto the porous structure of the straw carbon aerogel. This not only overcomes the problem of insufficient light absorption and difficulty in fully realizing photocatalytic potential caused by the wide band gap in existing aerogel composite-supported polymer antibacterial agents, but also solves the defects of high cost and poor long-term stability of existing gel composite-supported polymer antibacterial agents. Thus, it achieves the low-cost preparation of an aerogel-supported thiophene-based conjugated polymer antibacterial agent with excellent photocatalytic performance and long-term stability.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The first objective of this invention is to provide a method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent, comprising the following steps:

[0009] S1. Using 2,5-bis(trimethyltinyl)thiophene[3,2-b]thiophene and carboxythiophene dibromide as raw materials, a Stille coupling reaction was carried out in the presence of a catalyst and a solvent. During the coupling reaction, the trimethyltin group of 2,5-bis(trimethyltinyl)thiophene and the bromine atom of carboxythiophene dibromide underwent a condensation reaction to obtain a carboxyl-modified thiophene conjugated polymer.

[0010] S2. Mix straw with NaOH aqueous solution and perform alkali treatment to dissolve lignin and hemicellulose and expose cellulose to obtain alkali-treated straw.

[0011] S3. Under acidic conditions, the alkali-treated straw is placed in an aqueous solution of sodium hypochlorite for oxidation treatment to remove lignin and some hemicellulose, thus obtaining straw cellulose.

[0012] S4. First, disperse straw cellulose in water to form straw cellulose sol, then freeze-dry to obtain porous straw cellulose aerogel. Then, carbonize the porous straw cellulose aerogel to obtain straw carbon aerogel.

[0013] S5. The straw carbon aerogel is impregnated in a solution of carboxyl-modified thiophene conjugated polymer. During the impregnation process, the carboxyl groups of the carboxyl-modified thiophene conjugated polymer interact with the hydroxyl groups of the straw carbon aerogel through hydrogen bonding and are loaded onto the porous structure of the straw carbon aerogel. After drying, an aerogel-loaded thiophene conjugated polymer antibacterial agent is obtained.

[0014] Preferably, the mass ratio of the carboxyl-modified thiophene conjugated polymer to the straw carbon aerogel is 1:3 to 10.

[0015] Preferably, the mass ratio of 2,5-bis(trimethyltinyl)thiopheno[3,2-b]thiophene to carboxythiophene dibromide is 4 to 6:3.

[0016] Preferably, the carboxythiophene dibromide is selected from 2,5-dibromo-3-carboxythiophene or 2,5-dibromo-3,4-dicarboxythiophene.

[0017] Preferably, when the dibromocarboxythiophene is 2,5-dibromo-3-carboxythiophene, the resulting thiophene-based polymer is poly-2-(thieno[3,2-b]thieno-2-yl)thiophene-3-carboxylic acid, abbreviated as NK-COOH; when the dibromocarboxythiophene is 2,5-dibromo-3,4-dicarboxythiophene, the resulting thiophene-based polymer is poly-2-(thieno[3,2-b]thieno-2-yl)thiophene-3,4-dicarboxylic acid, abbreviated as NK-(COOH)2.

[0018] Preferably, the solvent is deoxygenated anhydrous toluene and dehydrated and deoxygenated DMF.

[0019] Preferably, the mass ratio of straw to NaOH aqueous solution is 1:45-55, wherein the concentration of NaOH aqueous solution is 1 mol / L-2 mol / L.

[0020] Preferably, the acidic conditions are provided by glacial acetic acid, and in the mixed aqueous solution of sodium hypochlorite and glacial acetic acid, the mass-volume ratio of sodium hypochlorite, glacial acetic acid and water is 9g-11g:2mL-3mL:150mL.

[0021] Preferably, the Stille coupling reaction is carried out under N2 protection at 100℃~120℃ with stirring at a stirring rate of 800r / min for 48h~72h.

[0022] Preferably, the freeze-drying conditions are: freezing at -40℃ to -18℃ for 24h to 48h.

[0023] Preferably, the carbonization treatment conditions are: under N2 protection, the temperature is increased to 460℃~550℃ at 5℃ / min and maintained for 1.5h~3h.

[0024] Preferably, the impregnation conditions are: stirring at 60℃~80℃ for 9h~12h.

[0025] Preferably, the oxidation treatment conditions are: stirring at 60℃~100℃ for 2h~3h.

[0026] Preferably, the drying conditions are: drying at 90℃~110℃ for 3h~4h.

[0027] Preferably, the straw is washed and crushed before alkali treatment to remove impurities and dust from the straw surface, reduce interference with subsequent reactions, and increase the specific surface area of ​​the straw by crushing, so that it can come into more full contact with the alkali solution during alkali treatment.

[0028] Preferably, in the solution of the carboxyl-modified thiophene conjugated polymer, the solvent is o-dichlorobenzene, and the carboxyl-modified thiophene conjugated polymer is slightly soluble in o-dichlorobenzene.

[0029] A second objective of this invention is to provide an aerogel-supported thiophene-based conjugated polymer antibacterial agent prepared by the above-described method.

[0030] A third objective of this invention is to provide the application of the above-mentioned aerogel-supported thiophene-based conjugated polymer antibacterial agent in the preparation of a photocatalytic antibacterial agent, which is capable of inhibiting methicillin-resistant Staphylococcus aureus and Escherichia coli.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. This invention provides a method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent. First, 2,5-bis(trimethyltinyl)thiophene[3,2-b]thiophene and carboxythiophene dibromide are used as raw materials, and a Stille coupling reaction is carried out in the presence of a catalyst and a solvent. The trimethyltin group of 2,5-bis(trimethyltinyl)thiophene undergoes a condensation reaction with the bromine atom of carboxythiophene dibromide to obtain a carboxyl-modified thiophene-based conjugated polymer. Straw is subjected to alkali treatment and oxidation treatment sequentially to obtain straw cellulose. The straw cellulose sol is then freeze-dried to obtain porous straw cellulose aerogel. This porous straw cellulose aerogel is then carbonized to obtain straw carbon aerogel. The straw carbon aerogel is impregnated in a solution of a carboxyl-modified thiophene-based conjugated polymer. During impregnation, the carboxyl groups of the carboxyl-modified thiophene-based conjugated polymer form hydrogen bonds with the hydroxyl groups of the straw carbon aerogel, which are then loaded onto the porous structure of the straw carbon aerogel. After drying, an aerogel-loaded thiophene-based conjugated polymer antibacterial agent is obtained. This invention not only overcomes the problems of insufficient light absorption and difficulty in fully utilizing photocatalytic potential caused by the wide band gap in existing aerogel composite-loaded polymer antibacterial agents, but also solves the defects of high cost and poor long-term stability of existing gel composite-loaded polymer antibacterial agents. Thus, it achieves the low-cost preparation of an aerogel-loaded thiophene-based conjugated polymer antibacterial agent with excellent photocatalytic performance and long-term stability.

[0033] The Stille coupling reaction is a one-step reaction with high yield and mild reaction conditions. Compared to other polymerization reactions with cumbersome steps and harsh conditions, the preparation method of this invention is simple and efficient, with significant cost advantages and cost-effectiveness. Furthermore, this invention uses agricultural waste straw as raw material, significantly reducing production costs.

[0034] Furthermore, the thiophene-based conjugated polymer with a conjugated structure used in this invention is itself a prominent photocatalytic material with a narrow bandgap (1 eV to 3 eV). In particular, the thiophene-based conjugated polymer in this invention employs a difused ring structure, which further narrows its bandgap, thereby significantly improving the photocatalytic performance of the material. In the aerogel-supported thiophene-based conjugated polymer antibacterial agent of this invention, a stable chemical bonding system is constructed through hydrogen bond interactions between the carboxyl groups of the carboxyl-modified thiophene-based conjugated polymer and the hydroxyl groups of the straw carbon aerogel. This interaction not only enhances the structural stability of the antibacterial agent but also effectively ensures its performance stability during long-term use.

[0035] 2. Compared with existing aerogel composite materials, hybrid aerogels, and aerogel-supported inorganic material photocatalytic antibacterial agents, the aerogel-supported thiophene-based conjugated polymer antibacterial agent of the present invention has high light utilization efficiency, stable properties, and can provide stable antibacterial action over a long period of time. This gives the aerogel-supported thiophene-based conjugated polymer antibacterial agent an extremely high cost-performance ratio, enabling it to be applied to photocatalytic antibacterial in multiple fields and occasions. Attached Figure Description

[0036] Figure 1 The images show SEM images of NK-COOH, CSCA, and CSCA-NK-COOH obtained in Example 1, where a is NK-COOH, b is CSCA, and c is CSCA-NK-COOH.

[0037] Figure 2 The graph shows the antibacterial efficiency and 10-cycle stability of CSCA-NK-COOH prepared in Example 1 against MRSA under full-band LED cold white light irradiation.

[0038] Figure 3 The graph shows the antibacterial efficiency and stability after 8 cycles of CSCA-NK-COOH prepared in Example 1 against E. coli under full-band LED cold white light irradiation.

[0039] Figure 4 The graph shows the antibacterial efficiency of CSCA-NK-COOH prepared in Example 1 against MRSA under full-band LED cold white light irradiation after one month.

[0040] Figure 5 The graph shows the antibacterial efficiency of CSCA-NK-COOH prepared in Example 1 against E. coli under full-band LED cold white light irradiation after one month. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the data in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that the technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased on the market or prepared by existing methods. Among them, the Tin reagent is 2,5-bis(trimethyltinyl)thieno[3,2-b]thiophene.

[0043] While some progress has been made in the research of antibacterial aerogel composite materials, the key issues that need to be addressed are how to effectively improve photocatalytic antibacterial properties, reduce preparation costs, and enhance long-term stability while ensuring their excellent thermal insulation and mechanical properties.

[0044] To address the problems existing in the prior art, this invention provides a method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent, comprising the following steps: using 2,5-bis(trimethyltinyl)thiophene[3,2-b]thiophene and carboxythiophene dibromide as raw materials, a Stille coupling reaction is carried out in the presence of a catalyst and a solvent, wherein the trimethyltin group of 2,5-bis(trimethyltinyl)thiophene undergoes a condensation reaction with the bromine atom of carboxythiophene dibromide to obtain a carboxyl-modified thiophene-based conjugated polymer; straw carbon aerogel is impregnated in a solution of the carboxyl-modified thiophene-based conjugated polymer, during which the carboxyl group of the carboxyl-modified thiophene-based conjugated polymer forms hydrogen bonds with the hydroxyl group of the straw carbon aerogel and is loaded onto the porous structure of the straw carbon aerogel; after drying, the aerogel-supported thiophene-based conjugated polymer antibacterial agent is obtained.

[0045] To address the problem that existing methods for preparing aerogel composite materials with supported polymer antibacterial agents result in insufficient light absorption and limited photocatalytic potential due to their wide band gaps, this invention utilizes a thiophene-based conjugated polymer with a conjugated structure, which itself possesses a narrow band gap (1 eV–3 eV) and is a promising photocatalytic structure. Furthermore, the thiophene-based conjugated polymer in this invention employs a difused ring structure, which further narrows its band gap, thereby significantly enhancing photocatalytic performance.

[0046] To address the issue that existing methods for preparing aerogel composite materials loaded with polymer antibacterial agents are relatively expensive, limiting their large-scale application, this invention utilizes the Stille coupling reaction, a one-step reaction with high yield and mild reaction conditions. Compared to other complex and demanding polymerization reactions, the preparation method of this invention offers significant cost advantages and cost-effectiveness.

[0047] To address the problem that existing gel composite-loaded polymer antibacterial agents suffer from poor stability during long-term use, severely hindering their practical production and application, this invention provides an aerogel-loaded thiophene-based conjugated polymer antibacterial agent. In this agent, the carboxyl-modified thiophene-based conjugated polymer contains carboxyl groups, while the straw carbon aerogel contains hydroxyl groups. During impregnation, the carboxyl groups of the carboxyl-modified thiophene-based conjugated polymer interact with the hydroxyl groups of the straw carbon aerogel through hydrogen bonding, thereby ensuring the long-term stability of this aerogel-loaded thiophene-based conjugated polymer antibacterial agent.

[0048] To enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments:

[0049] Example 1

[0050] A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent includes the following steps:

[0051] S1. Under nitrogen protection, 120 mg of Tin reagent, 90 mg of 2,5-dibromo-3-carboxythiophene, 30 mg of tetra(triphenylphosphine)palladium, 40 mL of dehydrated and deoxygenated toluene, and 8 mL of DMF were added to a double-necked flask and stirred at 100 °C with a stirring rate of 800 r / min for 48 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature and then transferred to a round-bottom flask for rotary evaporation. Ethanol was then added to the remaining concentrate for precipitation, and the solid was obtained by filtration. The solid was then subjected to Soxhlet purification using ethanol and acetone in sequence, and dried to obtain a monocarboxyl-modified thiophene conjugated polymer, denoted as NK-COOH.

[0052] S2. First, corn stalks are cut into small pieces, washed with deionized water, dried, and pulverized to obtain stalk powder. Then, the stalk powder and 1 mol / L NaOH aqueous solution are mixed at a mass ratio of 1:50 and stirred at 80°C for 3 hours. After the stirring reaction is completed, the mixture is washed with deionized water until neutral to obtain alkali-treated stalks. Finally, the alkali-treated stalks are immersed in 150 mL of aqueous solution containing 10 g sodium hypochlorite and 2.5 mL glacial acetic acid, stirred at 80°C for 3 hours, washed with deionized water, and placed in an oven to dry at 80°C for 4 hours to obtain stalk cellulose.

[0053] S3. First, disperse straw cellulose in 200 mL of deionized water and sonicate for 30 min to form a homogeneous sol, obtaining straw cellulose sol. Then, pour the straw cellulose sol into a beaker and freeze it at -18℃ for 24 h in a refrigerator, followed by freeze drying for 48 h to obtain porous straw cellulose aerogel. Finally, place the porous straw cellulose aerogel into a corundum crucible and purge it with nitrogen gas at a flow rate of 80 mL / min in a tube furnace. Heat the furnace to 500℃ at a rate of 5℃ / min and hold for 2 h to obtain straw carbon aerogel, denoted as CSCA.

[0054] S4. Add 2 mg of NK-COOH to o-dichlorobenzene and sonicate for 0.5 h. After heating to 60 °C, 10 mg of CSCA is immersed and stirred for 9 h. After filtration, the mixture is spread on a glass plate and dried at 100 °C for 3 h to obtain an aerogel-supported thiophene-based conjugated polymer antibacterial agent, denoted as CSCA-NK-COOH.

[0055] Example 2

[0056] A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent is the same as that in Example 1, except that the 2,5-dibromo-3-carboxythiophene in S1 is replaced with 2,5-dibromo-3,4-dicarboxythiophene, and includes the following steps:

[0057] S1. Under nitrogen protection, 120 mg of Tin reagent, 90 mg of 2,5-dibromo-3,4-dicarboxythiophene, 30 mg of tetra(triphenylphosphine)palladium, 40 mL of dehydrated and deoxygenated toluene, and 8 mL of DMF were added to a double-necked flask and stirred at 100 °C with a stirring rate of 800 r / min for 48 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature and then transferred to a round-bottom flask for rotary evaporation. Ethanol was then added to the remaining concentrate for precipitation, and the solid was obtained by filtration. The solid was then subjected to Soxhlet purification using ethanol and acetone in sequence, and dried to obtain a monocarboxyl-modified thiophene conjugated polymer, denoted as NK-(COOH)2.

[0058] S2. First, corn stalks are cut into small pieces, washed with deionized water, dried, and pulverized to obtain stalk powder. Then, the stalk powder and 1 mol / L NaOH aqueous solution are mixed at a mass ratio of 1:50 and stirred at 80°C for 3 hours. After the stirring reaction is completed, the mixture is washed with deionized water until neutral to obtain alkali-treated stalks. Finally, the alkali-treated stalks are immersed in 150 mL of aqueous solution containing 10 g sodium hypochlorite and 2.5 mL glacial acetic acid, stirred at 80°C for 3 hours, washed with deionized water, and placed in an oven to dry at 80°C for 4 hours to obtain stalk cellulose.

[0059] S3. First, disperse straw cellulose in 200 mL of deionized water and sonicate for 30 min to form a homogeneous sol, obtaining straw cellulose sol. Then, pour the straw cellulose sol into a beaker and freeze it at -18℃ for 24 h in a refrigerator, followed by freeze drying for 48 h to obtain porous straw cellulose aerogel. Finally, place the porous straw cellulose aerogel into a corundum crucible and purge it with nitrogen gas at a flow rate of 80 mL / min in a tube furnace. Heat the furnace to 500℃ at a rate of 5℃ / min and hold for 2 h to obtain straw carbon aerogel, denoted as CSCA.

[0060] S4. Add 2 mg of NK-(COOH)2 to o-dichlorobenzene and sonicate for 0.5 h. After heating to 60 °C, 10 mg of CSCA is immersed and stirred for 9 h. After filtration, it is spread on a glass plate and dried at 100 °C for 3 h to obtain an aerogel-supported thiophene-based conjugated polymer antibacterial agent, denoted as CSCA-NK-(COOH)2.

[0061] Example 3

[0062] A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent includes the following steps:

[0063] S1. Under nitrogen protection, 180 mg of Tin reagent, 90 mg of 2,5-dibromo-3-carboxythiophene, 30 mg of tetrakis(triphenylphosphine)palladium, 40 mL of dehydrated and deoxygenated toluene, and 8 mL of DMF were added to a double-necked flask and stirred at 120 °C with a stirring rate of 800 r / min for 72 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature and then transferred to a round-bottom flask for rotary evaporation. Ethanol was then added to the remaining concentrate for precipitation, and the mixture was filtered to obtain a solid. The solid was then subjected to Soxhlet purification using ethanol and acetone, and dried to obtain a monocarboxyl-modified thiophene conjugated polymer, denoted as NK-COOH.

[0064] S2. First, corn stalks are cut into small pieces, washed with deionized water, dried, and pulverized to obtain stalk powder. Then, the stalk powder and 2 mol / L NaOH aqueous solution are mixed at a mass ratio of 1:45 and stirred at 80°C for 3 hours. After the stirring reaction is completed, the mixture is washed with deionized water until neutral to obtain alkali-treated stalks. Finally, the alkali-treated stalks are immersed in a 150 mL aqueous solution containing 9 g sodium hypochlorite and 2 mL glacial acetic acid, stirred at 60°C for 3 hours, washed with deionized water, and placed in an oven to dry at 80°C for 4 hours to obtain stalk cellulose.

[0065] S3. First, disperse straw cellulose in 200 mL of deionized water and sonicate for 30 min to form a homogeneous sol, obtaining straw cellulose sol. Then, pour the straw cellulose sol into a beaker and freeze it at -18℃ for 48 h in a refrigerator, followed by freeze-drying for another 48 h to obtain porous straw cellulose aerogel. Finally, place the porous straw cellulose aerogel into a corundum crucible and purge it with nitrogen gas at a flow rate of 80 mL / min in a tube furnace. Heat the furnace to 460℃ at a rate of 5℃ / min and hold for 3 h to obtain straw carbon aerogel, denoted as CSCA.

[0066] S4. Add 1 mg of NK-COOH to o-dichlorobenzene and sonicate for 0.5 h. After heating to 60 °C, immerse 10 mg of CSCA in the mixture and stir for 9 h. After filtration, spread the mixture on a glass plate and dry it at 90 °C for 4 h to obtain an aerogel-supported thiophene-based conjugated polymer antibacterial agent, denoted as CSCA-NK-COOH.

[0067] Example 4

[0068] A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent includes the following steps:

[0069] S1. Under nitrogen protection, 120 mg of Tin reagent, 90 mg of 2,5-dibromo-3-carboxythiophene, 30 mg of tetrakis(triphenylphosphine)palladium, 40 mL of dehydrated and deoxygenated toluene, and 8 mL of DMF were added to a double-necked flask and stirred at 120 °C with a stirring rate of 800 r / min for 48 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature and then transferred to a round-bottom flask for rotary evaporation. Ethanol was then added to the remaining concentrate for precipitation, and the solid was obtained by filtration. The solid was then subjected to Soxhlet purification using ethanol and acetone in sequence, and dried to obtain a monocarboxyl-modified thiophene conjugated polymer, denoted as NK-COOH.

[0070] S2. First, corn stalks are cut into small pieces, washed with deionized water, dried, and pulverized to obtain stalk powder. Then, the stalk powder and 1 mol / L NaOH aqueous solution are mixed at a mass ratio of 1:55 and stirred at 80°C for 3 hours. After the stirring reaction is completed, the mixture is washed with deionized water until neutral to obtain alkali-treated stalks. Finally, the alkali-treated stalks are immersed in a 150 mL aqueous solution containing 11 g sodium hypochlorite and 3 mL glacial acetic acid, stirred at 100°C for 2 hours, washed with deionized water, and placed in an oven to dry at 80°C for 4 hours to obtain stalk cellulose.

[0071] S3. First, disperse straw cellulose in 200 mL of deionized water and sonicate for 30 min to form a homogeneous sol, obtaining straw cellulose sol. Then, pour the straw cellulose sol into a beaker and freeze it at -40℃ for 48 h in a refrigerator, followed by freeze-drying for another 48 h to obtain porous straw cellulose aerogel. Finally, place the porous straw cellulose aerogel into a corundum crucible and purge it with nitrogen gas at a flow rate of 80 mL / min in a tube furnace. Heat the furnace to 550℃ at a rate of 5℃ / min and hold for 1.5 h to obtain straw carbon aerogel, denoted as CSCA.

[0072] S4. Add 3 mg of NK-COOH to o-dichlorobenzene and sonicate for 0.5 h. After heating to 80 °C, immerse 10 mg of CSCA in the mixture and stir for 12 h. After filtration, spread the mixture on a glass plate and dry it at 110 °C for 3 h to obtain an aerogel-supported thiophene-based conjugated polymer antibacterial agent, denoted as CSCA-NK-COOH.

[0073] Comparative Example 1

[0074] A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent includes the following steps:

[0075] S1. Under nitrogen protection, 120 mg of Tin reagent, 90 mg of 2,5-dibromo-3-carboxythiophene, 30 mg of tetra(triphenylphosphine)palladium, 40 mL of dehydrated and deoxygenated toluene, and 8 mL of DMF were added to a double-necked flask and stirred at 100 °C with a stirring rate of 800 r / min for 48 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature and then transferred to a round-bottom flask for rotary evaporation. Ethanol was then added to the remaining concentrate for precipitation, and the solid was obtained by filtration. The solid was then subjected to Soxhlet purification using ethanol and acetone in sequence, and dried to obtain a monocarboxyl-modified thiophene conjugated polymer, denoted as NK-COOH.

[0076] S2. First, corn stalks are cut into small pieces, washed with deionized water, dried, and pulverized to obtain stalk powder. Then, the stalk powder and 1 mol / L NaOH aqueous solution are mixed at a mass ratio of 1:50 and stirred at 80°C for 3 hours. After the stirring reaction is completed, the mixture is washed with deionized water until neutral to obtain alkali-treated stalks. Finally, the alkali-treated stalks are immersed in 150 mL of aqueous solution containing 10 g sodium hypochlorite and 2.5 mL glacial acetic acid, stirred at 80°C for 3 hours, washed with deionized water, and placed in an oven to dry at 80°C for 4 hours to obtain stalk cellulose.

[0077] S3. First, disperse straw cellulose in 200 mL of deionized water and sonicate for 30 min to form a homogeneous sol, which is straw cellulose sol. Then, pour the straw cellulose sol into a beaker, place it in a refrigerator and freeze at -18℃ for 24 h, and then continue to freeze-dry for 48 h to obtain porous straw cellulose aerogel, denoted as CSFA.

[0078] S4. Add 2 mg of NK-COOH to o-dichlorobenzene and sonicate for 0.5 h. After heating to 60 °C, 10 mg of CSFA is immersed and stirred for 9 h. After filtration, it is spread on a glass plate and dried at 100 °C for 3 h to obtain an aerogel-supported thiophene-based conjugated polymer antibacterial agent, denoted as CSFA-NK-COOH.

[0079] Comparative Example 2

[0080] A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent is the same as that in Example 2, except that the 2,5-dibromo-3-carboxythiophene in S1 is replaced with 2,5-dibromo-3,4-dicarboxythiophene. The method includes the following steps:

[0081] S1. Under nitrogen protection, 120 mg of Tin reagent, 90 mg of 2,5-dibromo-3,4-dicarboxythiophene, 30 mg of tetra(triphenylphosphine)palladium, 40 mL of dehydrated and deoxygenated toluene, and 8 mL of DMF were added to a double-necked flask and stirred at 100 °C with a stirring rate of 800 r / min for 48 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature and then transferred to a round-bottom flask for rotary evaporation. Ethanol was then added to the remaining concentrate for precipitation, and the solid was obtained by filtration. The solid was then subjected to Soxhlet purification using ethanol and acetone in sequence, and dried to obtain a monocarboxyl-modified thiophene conjugated polymer, denoted as NK-(COOH)2.

[0082] S2. First, corn stalks are cut into small pieces, washed with deionized water, dried, and pulverized to obtain stalk powder. Then, the stalk powder and 1 mol / L NaOH aqueous solution are mixed at a mass ratio of 1:50 and stirred at 80°C for 3 hours. After the stirring reaction is completed, the mixture is washed with deionized water until neutral to obtain alkali-treated stalks. Finally, the alkali-treated stalks are immersed in 150 mL of aqueous solution containing 10 g sodium hypochlorite and 2.5 mL glacial acetic acid, stirred at 80°C for 3 hours, washed with deionized water, and placed in an oven to dry at 80°C for 4 hours to obtain stalk cellulose.

[0083] S3. First, disperse straw cellulose in 200 mL of deionized water and sonicate for 30 min to form a homogeneous sol, which is straw cellulose sol. Then, pour the straw cellulose sol into a beaker, place it in a refrigerator and freeze at -18℃ for 24 h, and then continue to freeze-dry for 48 h to obtain porous straw cellulose aerogel, denoted as CSFA.

[0084] S4. Add 2 mg of NK-COOH to o-dichlorobenzene and sonicate for 0.5 h. After heating to 60 °C, immerse 10 mg of CSFA in the mixture and stir for 9 h. After filtration, spread the mixture on a glass plate and dry it at 100 °C for 3 h to obtain an aerogel-supported thiophene-based conjugated polymer antibacterial agent, denoted as CSFA-NK-(COOH)2.

[0085] The aerogel-supported thiophene-based conjugated polymer antibacterial agents from Examples 1-2 and Comparative Examples 1-2 were subjected to photocatalytic antibacterial tests. The test conditions were a full-band LED cold white light source with a light intensity of 150 mW / cm². 2 .

[0086] The specific operating steps are as follows: Using methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) as subjects, the bacterial cells were cultured in nutrient solution at 37°C for 18 hours under aseptic conditions. Metabolic products were removed by centrifugation, and then diluted with 0.01 mol / L PBS (pH 7.4) to obtain approximately 10 [units of solution, not specified in the original text].7 CFU bacterial suspension.

[0087] The bacterial suspension was kept at 20 mL, and 2 mg / mL of the aerogel-loaded thiophene-based conjugated polymer antibacterial agent from Examples 1-2 and Comparative Examples 1-2 were added respectively. The suspension was then irradiated with LED white light as needed. Samples were taken at specified time intervals of 0, 20 min, 40 min, 60 min, 80 min, 100 min, 120 min, and 140 min. The collected reaction solutions were serially diluted with PBS solution, and the final 100 μL of the diluted bacterial suspension was spread on freshly prepared TSA plates and incubated at 37℃±0.5℃ for 16 h. Finally, the colonies were counted and photographed.

[0088] The cyclic test involved centrifuging and sterilizing the reaction mixture at high temperature, washing it three times with deionized water, and then drying it. The mixture was then reused in the antibacterial experiment under the same conditions. One month later, the antibacterial efficiency was tested by using the prepared material for one photocatalytic antibacterial test, followed by centrifugation, sterilization, washing, and drying. After one month of storage, the material was again used in the photocatalytic sterilization reaction system for testing under the same conditions. The results are shown in Table 1.

[0089] Table 1. Bactericidal time, antibacterial rate, and cyclic stability of aerogel-supported thiophene-based conjugated polymer antibacterial agents for MRSA and E. coli in Examples 1-2 and Comparative Examples 1-2.

[0090]

[0091]

[0092] The results in Table 1 show that Example 1 exhibits the best antibacterial effect and the best cyclic stability. After 40 minutes of visible light irradiation, the kill rate against methicillin-resistant Staphylococcus aureus (MRSA) is close to 100%, and the antibacterial effect remains essentially unchanged after 10 cycles. After 120 minutes of visible light irradiation, the kill rate against Escherichia coli (E. coli) exceeds 90%, and the antibacterial effect remains above 85% after 8 cycles. Furthermore, the photocatalytic antibacterial efficiency of the aerogel-loaded thiophene-based conjugated polymer antibacterial agent in Example 1 remains at a high level of sterilization efficiency even after one month. After 40 minutes of visible light irradiation, the kill rate against MRSA reaches as high as 86%; after 120 minutes of visible light irradiation, the kill rate against E. coli is approximately 80%.

[0093] observe Figure 1It was found that the monocarboxylated thiophene conjugated polymer NK-COOH particles prepared in Example 1 were successfully loaded onto straw carbon aerogel CSCA, thereby constructing CSCA-NK-COOH.

[0094] observe Figure 2 The results showed that the CSCA-NK-COOH prepared in Example 1 exhibited the best antibacterial effect and the best cyclic stability. After 40 minutes of visible light irradiation, the kill rate against methicillin-resistant Staphylococcus aureus was close to 100%, and the antibacterial effect did not show a significant decrease after 10 cycles.

[0095] observe Figure 3 It was found that the CSCA-NK-COOH prepared in Example 1 had a kill rate of over 90% against Escherichia coli after 120 min of visible light irradiation, and the antibacterial effect remained above 85% after 8 cycles of testing.

[0096] observe Figure 4 The results show that the CSCA-NK-COOH prepared in Example 1 exhibits excellent long-term stability in its antibacterial properties. Specifically, after a one-month storage period, the aerogel-loaded thiophene-based conjugated polymer antibacterial agent maintained a high bactericidal rate without significant performance degradation. After 40 minutes of visible light irradiation, CSCA-NK-COOH achieved an 86% kill rate against methicillin-resistant Staphylococcus aureus (MRSA), which fully demonstrates the high efficiency and durability of this aerogel-loaded thiophene-based conjugated polymer antibacterial agent in antibacterial applications.

[0097] observe Figure 5 The results showed that the CSCA-NK-COOH prepared in Example 1 exhibited particularly outstanding long-term stability in its antibacterial properties. After a one-month storage period, the photocatalytic antibacterial efficiency of the aerogel-loaded thiophene-based conjugated polymer antibacterial agent remained stably maintained in the high bactericidal rate range, without significant performance degradation. Under continuous visible light irradiation for 120 minutes, CSCA-NK-COOH achieved a kill rate of approximately 80% against Escherichia coli, further verifying the high efficiency and long-lasting effect of this material in antibacterial applications.

[0098] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0099] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing an aerogel-supported thiophene-based conjugated polymer antibacterial agent, characterized in that, Includes the following steps: Using 2,5-bis(trimethyltinyl)thiophene[3,2-b]thiophene and carboxythiophene dibromide as raw materials, a Stille coupling reaction was carried out in the presence of a catalyst and a solvent. The trimethyltin group of 2,5-bis(trimethyltinyl)thiophene and the bromine atom of carboxythiophene dibromide underwent a condensation reaction to obtain a carboxyl-modified thiophene conjugated polymer. Straw carbon aerogel was impregnated in a solution of carboxyl-modified thiophene conjugated polymer. During the impregnation process, the carboxyl groups of the carboxyl-modified thiophene conjugated polymer formed hydrogen bonds with the hydroxyl groups of the straw carbon aerogel and were loaded onto the porous structure of the straw carbon aerogel. After drying, an aerogel-loaded thiophene conjugated polymer antibacterial agent was obtained.

2. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 1, characterized in that, The mass ratio of carboxyl-modified thiophene conjugated polymer to straw carbon aerogel is 1:3 to 10.

3. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 1, characterized in that, The mass ratio of 2,5-bis(trimethyltinyl)thieno[3,2-b]thiophene to carboxythiophene dibromide is 4–6:

3.

4. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 3, characterized in that, Dibromocarboxythiophene is selected from 2,5-dibromo-3-carboxythiophene or 2,5-dibromo-3,4-dicarboxythiophene.

5. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 1, characterized in that, The impregnation conditions are: stirring at 60℃~80℃ for 9h~12h.

6. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 1, characterized in that, The conditions for the Stille coupling reaction are: under N2 protection, stirring at 100℃~120℃ for 48h~72h.

7. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 1, characterized in that, Straw carbon aerogel was prepared according to the following steps: The straw is first treated with alkali and then oxidized to remove lignin and some hemicellulose, and expose the cellulose to obtain straw cellulose. The straw cellulose is then dispersed in water to obtain straw cellulose sol. First, the straw cellulose sol is freeze-dried to obtain porous straw cellulose aerogel. Then, the porous straw cellulose aerogel is carbonized to obtain straw carbon aerogel.

8. The method for preparing the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 7, characterized in that, The carbonization conditions are as follows: under N2 protection, the temperature is increased to 460℃~550℃ at a rate of 5℃ / min and maintained for 1.5h~3h.

9. An aerogel-supported thiophene-based conjugated polymer antibacterial agent prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the aerogel-supported thiophene-based conjugated polymer antibacterial agent according to claim 9 in the preparation of a photocatalytic antibacterial agent, characterized in that, The photocatalytic antibacterial agent can inhibit methicillin-resistant Staphylococcus aureus and Escherichia coli.

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