Bacteriostatic high internal phase emulsion as well as preparation method and application thereof

Abstract

The invention provides a bacteriostatic high-internal-phase emulsion and a preparation method and application thereof, the bacteriostatic high-internal-phase emulsion is a water-in-oil emulsion, and comprises an oil phase and a water phase; the oil phase comprises a polymeric monomer, a cross-linking agent and an emulsifier; the water phase comprises water and electrolyte; the emulsifying agent is a hydrophilic-hydrophobic-bacteriostatic triblock polymer; the hydrophilic-hydrophobic-bacteriostatic triblock polymer is a polyethylene glycol-polystyrene-chitosan triblock polymer (PEG-PS-CS), and the hydrophilic-hydrophobic-bacteriostatic triblock polymer is a hydrophilic-hydrophobic-bacteriostatic triblock polymer; at least one of the oil phase and the water phase includes an initiator. According to the invention, the polyethylene glycol-polystyrene-chitosan triblock polymer with antibacterial activity is introduced into the high internal phase emulsion as the emulsifier, so that the prepared porous material has better antibacterial activity and high mechanical strength.

Description

[0001] This application claims priority to patent application number 2025115854826 (the earlier application was filed on October 31, 2025, and is entitled "An antibacterial high internal phase emulsion and its preparation method and application"). Technical Field

[0002] This invention belongs to the field of high internal phase emulsion technology, and relates to an antibacterial high internal phase emulsion, its preparation method, and its applications. Specifically, it relates to an antibacterial high internal phase emulsion using polyethylene glycol-polystyrene-chitosan triblock copolymer as an emulsifier, its preparation method, and porous polymer materials prepared from this emulsion. This porous polymer material is particularly suitable for biomedical applications (such as wound dressings and tissue engineering scaffolds), food packaging, water treatment, and other fields where synergistic requirements for antibacterial properties and mechanical strength are needed. Background Technology

[0003] High internal phase emulsion (HIPE) is an emulsion system with a dispersed phase volume fraction greater than 74%. Due to its unique structure and properties, it has shown great application potential in the fields of materials science, biomedicine, and cosmetics. Porous foam materials made from HIPE can also be used in the field of daily chemical hygiene products, such as sanitary napkins and dressings, and have advantages such as absorption, flow conduction, water retention, anti-backflow, or slow release.

[0004] Traditional surfactants (also known as emulsifiers) or stabilizers suffer from drawbacks such as poor stability, irregular pore structure, uncontrollable size, uncontrollable open / closed pore state, and low mechanical strength when added in excessive amounts (approximately 15-30% of the oil phase mass fraction). In contrast, amphiphilic block copolymers (BCPs) offer easily controllable structure and hydrophilic-lipophilic balance (HLB) values, providing crucial assurance for the stability of HIPE. However, traditional HIPE systems have limitations in stability and functionality, particularly in antibacterial properties. Bacterial contamination can lead to material deterioration, product failure, and even serious problems such as infections in biomedical applications.

[0005] Especially when applying high internal phase emulsion foams to the biomedical field (such as wound dressings), the antibacterial properties of the materials are crucial. However, adding antibacterial agents through physical blending carries the risk of easy migration and short-lasting effects. Therefore, developing an endogenous emulsifier with its own antibacterial function is of great significance for preparing high-performance antibacterial high internal phase emulsion materials. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an antibacterial high internal phase emulsion, its preparation method, and its application.

[0007] To achieve the object of the present application, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a bacteriostatic high internal phase emulsion, which comprises an oil phase and an aqueous phase;

[0009] The oil phase comprises a polymerized monomer, a crosslinking agent, and an emulsifier;

[0010] The aqueous phase comprises water and an electrolyte;

[0011] The emulsifier is a hydrophilic-hydrophobic-bacteriostatic triblock polymer;

[0012] The hydrophilic-hydrophobic-bacteriostatic triblock polymer is a polyethylene glycol-polystyrene-chitosan triblock polymer (PEG-PS-CS);

[0013] At least one of the oil phase and the aqueous phase comprises an initiator.

[0014] The present application introduces a polyethylene glycol-polystyrene-chitosan triblock polymer (PEG-PS-CS) with bacteriostatic properties as an emulsifier in a high internal phase emulsion, which has the following effects:

[0015] 1) Stabilize the emulsion: the PEG hydrophilic segment extends into the aqueous phase droplet, providing steric hindrance stabilization; the PS rigid segment provides solubility and anchoring in the oil phase; the CS functional segment provides pH responsiveness, antibacterial properties, and targeting; and the PEG / PS chain length can be adjusted to precisely control the stability of the emulsion.

[0016] 2) Improve the strength of the porous material: the CS block is crosslinked with PEG-PS through hydrogen bonds to form a composite network, significantly improving the mechanical strength of the porous material. The effect can reach: the compression modulus of the porous material ≥ 8 MPa.

[0017] 3) Reduce the amount of surfactant: the role of this triblock polymer is equivalent to that of a small molecule surfactant, and the addition amount is 1wt%-5wt% of the total mass of the oil phase monomer, which can stabilize more than 90% of the aqueous phase (while the traditional use of PEG-PS requires an addition amount of 5wt%-15wt% of the total mass of the monomer).

[0018] 4) Long-acting antibacterial function: the number of positive charges of the amino group (-NH3 + ) of the CS block allows it to bind more strongly to the cell wall of bacteria, thereby showing higher activity. The electrostatic interaction disrupts the bacterial cell membrane, leading to leakage of intracellular substances.

[0019] Preferably, the polyethylene glycol-polystyrene-chitosan triblock polymer (PEG-PS-CS) is prepared by the following method:

[0020] (1) mixing monomethoxypolyethylene glycol (mPEG-OH), chain transfer agent, first activator and solvent, ice bath cooling, then adding the mixture of second activator and solvent, reaction, post-treatment, to obtain mPEG-CTA;

[0021] (2) mixing the mPEG-CTA, styrene, initiator and solvent, reaction, post-treatment, to obtain mPEG-PS-CTA;

[0022] (3) mixing the mPEG-PS-CTA and solvent, then adding reducing agent, first reaction, first post-treatment, to obtain mPEG-PS-SH;

[0023] mixing the mPEG-PS-SH and solvent, then adding azidation reagent, second reaction, second post-treatment, to obtain PEG-PS-N3;

[0024] (4) mixing chitosan (CS) and acetic acid buffer, then adding organic acid, activator, reaction, post-treatment, to obtain Alkyne-CS;

[0025] (5) mixing the PEG-PS-N3 and organic solvent, to obtain PEG-PS-N3 solution, mixing the Alkyne-CS and acetic acid aqueous solution, to obtain Alkyne-CS solution, mixing the PEG-PS-N3 solution and Alkyne-CS solution, then adding catalyst, optionally ligand, reaction, post-treatment, to obtain PEG-PS-CS, that is, the polyethylene glycol-polystyrene-chitosan triblock polymer.

[0026] The preparation method of the polyethylene glycol-polystyrene-chitosan triblock polymer provided by the application is as follows: first, synthesizing PEG-PS double block (hydrophilic-hydrophobic section) through RAFT method, then, modifying CS end group (introducing alkyne group), converting PEG-PS end group (azidation), coupling (CuAAC) through click chemistry, and finally, preparing PEG-PS-CS triblock polymer through deprotection, dialysis purification and freeze-drying. The CS block of the triblock polymer molecule has a large number of reactive sites, which can enhance the interface stability in the HIPE emulsification stage and the mechanical strength in the solidification stage, and at the same time, the antibacterial property is introduced, so that the application range of HIPE is widened.

[0027] Preferably, the number average molecular weight (Mn) of the monomethoxypolyethylene glycol in step (1) is 2000-5000 Da, for example, 2000 Da, 2500 Da, 3000 Da, 3500 Da, 4000 Da, 4500 Da, 5000 Da, etc.

[0028] Preferably, the chain transfer agent in step (1) is a carboxyl type RAFT agent, including 4-cyano-4-(phenylthiocarbamoylthio) pentanoic acid (CPADB).

[0029] Preferably, the first activator in step (1) includes 4-dimethylaminopyridine (DMAP).

[0030] Preferably, the second activator in step (1) includes N,N'-dicyclohexyl carbodiimide (DCC).

[0031] Preferably, the molar ratio of the monomethoxypolyethylene glycol, the chain transfer agent, the first activator, and the second activator in step (1) is 1: (1.2~1.5): (0.05~0.2): (1.2~1.5), and each of 1.2~1.5, for example, can be 1.2, 1.3, 1.4, 1.5, etc., and 0.05~0.2, for example, can be 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.16, 0.18, 0.2, etc.

[0032] Preferably, the solvent in step (1) includes dichloromethane (DCM).

[0033] Preferably, the temperature of the reaction in step (1) is 20~30℃, for example, 20℃, 25℃, 30℃, etc., and the time of the reaction is 20~30 hours, for example, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, etc.

[0034] Preferably, the post-treatment in step (1) includes filtration, concentration, centrifugation, and vacuum drying.

[0035] Preferably, the initiator in step (2) includes azobisisobutyronitrile (AIBN). Preferably, the azobisisobutyronitrile is recrystallized and purified before use.

[0036] Preferably, the molar ratio of the mPEG-CTA, the styrene, and the initiator in step (2) is 1: (150~250): (0.1~0.5), and 150~250, for example, can be 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, etc., and 0.1~0.5, for example, can be 0.1, 0.2, 0.3, 0.4, 0.5, etc.

[0037] Preferably, the styrene in step (2) is purified to remove the polymerization inhibitor before use.

[0038] Preferably, the solvent in step (2) includes toluene (anhydrous and oxygen-free).

[0039] Preferably, the temperature of the reaction in step (2) is 65-75℃, such as 65℃, 70℃, 75℃, etc., and the reaction time is 6-24 hours, such as 6 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 24 hours, etc.

[0040] Preferably, the post-treatment in step (2) comprises precipitation, filtration, and drying.

[0041] Preferably, the solvent in step (3) comprises N,N-dimethylformamide (DMF).

[0042] Preferably, the reducing agent in step (3) comprises n-butylamine.

[0043] Preferably, the mass ratio of mPEG-PS-CTA to reducing agent in step (3) is 1:(1-1.5), such as 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, etc.

[0044] Preferably, the temperature of the first reaction in step (3) is 20-30℃, such as 20℃, 25℃, 30℃, etc., and the reaction time is 20-30h, such as 20h, 24h, 28h, 30h, etc.

[0045] Preferably, the post-treatment in step (3) comprises precipitation, centrifugation, and drying.

[0046] Preferably, the azidation reagent in step (3) comprises N-(2-azidoethyl)maleimide (N3-PEG-Mal).

[0047] Preferably, the molar ratio of mPEG-PS-CTA to azidation reagent in step (3) is 1:(1-2), such as 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, etc.

[0048] Preferably, the temperature of the second reaction in step (3) is 20-30℃, such as 20℃, 25℃, 30℃, etc., and the reaction time is 20-30h, such as 20h, 24h, 28h, 30h, etc.

[0049] Preferably, both the first reaction and the second reaction in step (3) are carried out under the protection of an inert gas (such as nitrogen, etc.).

[0050] Preferably, the post-treatment in step (3) comprises precipitation, filtration, washing, and drying.

[0051] Preferably, the degree of deacetylation of the chitosan in step (4) is greater than 85%, such as 88%, 90%, etc., and the weight average molecular weight (Mw) is 10-50 kDa, such as 10 kDa, 20 kDa, 30 kDa, 40 kDa, 50 kDa, etc.

[0052] Preferably, the concentration of the acetic acid buffer in step (4) is 0.05-0.2 mol / L, such as 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, 0.12 mol / L, 0.14 mol / L, 0.15 mol / L, 0.16 mol / L, 0.18 mol / L, 0.2 mol / L, etc.

[0053] Preferably, the organic acid in step (4) comprises pentynoic acid and / or 5-hexynoic acid.

[0054] Preferably, the activating agent in step (4) comprises N-hydroxysuccinimide (NHS) and / or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC·HCl).

[0055] Preferably, the molar ratio of the chitosan, the organic acid, and the activating agent in step (4) is 1:(10-20):(40-60), and 10-20 can be 10, 12, 14, 15, 16, 18, 20, etc., and 40-60 can be 40, 42, 44, 45, 46, 48, 50, 52, 54, 55, 56, 58, 60, etc.

[0056] Preferably, the temperature of the reaction in step (4) is 20-30℃, such as 20℃, 25℃, 30℃, etc., and the reaction time is 20-30 hours, such as 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, etc.

[0057] Preferably, the reaction in step (4) is carried out in the dark.

[0058] Preferably, the post-treatment in step (4) comprises dialysis and freeze-drying.

[0059] Preferably, the molar ratio of PEG-PS-N3 and Alkyne-CS in step (5) is 1:(0.8-1.2), such as 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

[0060] Preferably, the organic solvent in step (5) comprises N,N-dimethylformamide (DMF).

[0061] Preferably, the concentration of the acetic acid aqueous solution in step (5) is 0.5%-2%, such as 0.5%, 1%, 1.5%, 2%, etc.

[0062] Preferably, the volume ratio of the organic solvent and the acetic acid aqueous solution in step (5) is (6-8):(2-4), for example, 6, 6.5, 7, 7.5, 8, etc. for 6-8, and 2, 2.5, 3, 3.5, 4, etc. for 2-4.

[0063] Preferably, the catalyst in step (5) comprises CuSO4·5H2O and / or sodium ascorbate (NaAsc).

[0064] Preferably, the ligand in step (5) comprises any one of tris(3-hydroxypropyltriazolylmethyl)amine (THPTA), tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA), pentamethyldiethylenetriamine (PMDETA) or a combination of at least two thereof.

[0065] Preferably, the molar ratio of PEG-PS-N3 to the catalyst in step (5) is 1:(0.5-0.7), for example, 1:0.5, 1:0.6, 1:0.7, etc.

[0066] Preferably, the molar ratio of PEG-PS-N3 to the ligand in step (5) is 1:(0.1-0.3), for example, 1:0.1, 1:0.2, 1:0.3, etc.

[0067] Preferably, the temperature of the reaction in step (5) is 20-30℃, for example, 20℃, 25℃, 30℃, etc., and the reaction time is 24-48 hours, for example, 24 hours, 28 hours, 30 hours, 34 hours, 38 hours, 42 hours, 46 hours, 48 hours, etc.

[0068] Preferably, the reaction in step (5) is carried out in the dark.

[0069] Preferably, the post-treatment in step (5) comprises dialysis, freeze-drying.

[0070] Preferably, the polymerization monomer comprises any one of a vinyl-based monomer, an acrylate-based monomer or a methacrylate-based monomer or a combination of at least two thereof.

[0071] Preferably, the polymerizable monomer comprises any one or a combination of at least two of styrene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, methyl methacrylate, butyl acrylate, stearyl acrylate, ethylhexyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, myristyl acrylate, benzyl acrylate, nonyl phenyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, and stearyl methacrylate.

[0072] Preferably, the crosslinking agent comprises a multifunctional crosslinking monomer.

[0073] Preferably, the crosslinking agent comprises any one or a combination of at least two of divinyl benzene, an acrylate containing at least two double bonds, a monomer containing methacrylate groups.

[0074] Preferably, the crosslinking agent comprises any one or a combination of at least two of divinyl benzene (DVB), 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,12-dodecanediol dimethacrylate, 1,14-tetradecanediol dimethacrylate, ethylene glycol dimethacrylate, neopentyl glycol diacrylate (2,2-dimethylpropanediol diacrylate), hexanediol acrylate methacrylate, sorbitol pentaacrylate.

[0075] Preferably, the initiator in the oil phase comprises a photoinitiator and / or a thermal initiator.

[0076] Preferably, the photoinitiator comprises any one or a combination of at least two of Irgacure® 819, benzylketal, a-hydroxyalkylphenone, a-aminoalkylphenone, and acylphosphine oxide.

[0077] Preferably, the thermal initiator comprises benzoyl peroxide (BPO).

[0078] Preferably, in the oil phase, the mass ratio of the polymerizable monomer to the crosslinking agent is (1~20):1, such as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, and the like.

[0079] Preferably, in the oil phase, the amount of the emulsifier is 1% to 10% of the sum of the mass of the polymeric monomer and the crosslinking agent, such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc., preferably 1% to 5%.

[0080] Preferably, in the oil phase, the amount of the initiator is 0% to 10% of the sum of the mass of the polymerizing monomer and the crosslinking agent, for example, 0, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0081] Preferably, the electrolyte comprises sodium chloride and / or calcium chloride. The electrolyte can increase the viscosity of the aqueous phase and inhibit Ostwald ripening.

[0082] Preferably, the concentration of the electrolyte in the aqueous phase is 0.01~1 mol / L, for example, 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, etc.

[0083] Preferably, the initiator in the aqueous phase includes any one or a combination of at least two of persulfates, azo compounds, redox pairs, and water-soluble photoinitiators. The initiator in the aqueous phase can be used to enhance the stability of interfacial polymerization (but should avoid conflict with the oil-phase initiator).

[0084] Preferably, the persulfate includes any one or a combination of at least two of ammonium persulfate, sodium persulfate, and potassium persulfate.

[0085] Preferably, the azo group includes 2,2'-azobis(N,N′-dimethyleneisobutylamidine) dihydrochloride.

[0086] Preferably, the redox pair includes any one or a combination of at least two of persulfate-bisulfite and persulfate-ascorbic acid.

[0087] Preferably, the water-soluble photoinitiator comprises any one or a combination of at least two of the following: 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; dehydrated 2,2′-azobis[2-(2-imidazolin-2-yl)propane] disulfate; 2,2′-azobis(1-imino-1-pyrrolo-2-ethylpropane) dihydrochloride; 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propamide]; 2,2′-azobis(2-methylpropanediamine) dihydrochloride; 2,2′-dicarboxymethoxydibenzylacetone, 4,4′-dicarboxymethoxydibenzylacetone, 4,4′-dicarboxymethoxydibenzylcyclohexanone, and 4-dimethylamino-4′-carboxymethoxydibenzylacetone.

[0088] Preferably, the amount of initiator in the aqueous phase is 0% to 10%, based on the total mass of the aqueous phase as 100%, for example, 0, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0089] Preferably, the volume ratio of the oil phase to the water phase is 1:(4~45), for example, it can be 1:10, 1:12, 1:15, 1:18, 1:20, 1:22, 1:25, 1:30, 1:35, 1:40, 1:45, etc., preferably 1:(10~25).

[0090] In a second aspect, the present invention provides a method for preparing an antibacterial high internal phase emulsion as described in the first aspect, the preparation method comprising the following steps:

[0091] (S1) Mix the polymerizable monomer, crosslinking agent, and optionally initiator, then add the emulsifier and mix again to obtain the oil phase;

[0092] (S2) Water and electrolyte, and optionally an initiator, are mixed to obtain an aqueous phase;

[0093] (S3) Add the aqueous phase to the oil phase and mix until a viscous, uniform, white paste with no visible water phase separation is formed, which is the antibacterial high internal phase emulsion.

[0094] Wherein, at least one of the oil phase and the aqueous phase includes an initiator.

[0095] Preferably, the mixing in step (S1) includes magnetic stirring.

[0096] Preferably, the remixing in step (S1) includes ultrasonic dispersion or vigorous stirring.

[0097] Preferably, the addition in step (S3) includes dropwise addition, preferably slow dropwise addition.

[0098] Preferably, the mixing in step (S3) includes any one of homogenization, ultrasonication, and stirring.

[0099] Preferably, the homogenization speed is 500~1000 rpm, such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc., the homogenization time is 5~15 min, such as 5 min, 10 min, 15 min, etc., and the system temperature during the homogenization process is 20~30℃, such as 20℃, 25℃, 30℃, etc. The homogenization can be carried out in a high-shear stirrer (such as a rotor-stator homogenizer) or a high-power mechanical stirrer.

[0100] The key to step (S3) is to control the rate of addition of the aqueous phase and the shear strength (homogeneous rotation speed) to ensure the formation of fine and uniform water droplets (D≈10-50μm).

[0101] Thirdly, the present invention provides an antibacterial porous material, which is prepared from the antibacterial high internal phase emulsion described in the first aspect.

[0102] Preferably, the antibacterial porous material is prepared by the following method:

[0103] An antibacterial high internal phase emulsion is added to a mold (such as a glass tube or Teflon mold), cured, and the cured product is extracted and freeze-dried to obtain the antibacterial porous material (which is a white, lightweight, open-pore PolyHIPE porous material).

[0104] The antibacterial high internal phase emulsion includes the antibacterial high internal phase emulsion as described in the first aspect.

[0105] Preferably, the curing temperature is 70~90℃, such as 70℃, 85℃, 90℃, etc., and the curing time is 4~24 hours, such as 4 hours, 8 hours, 12 hours, 16 hours, 20 hours, 24 hours, etc.

[0106] Preferably, the solvent used for extraction includes a mixture of ethanol and water. The purpose of extraction is to remove unreacted monomers, emulsifiers (i.e., antibacterial triblock polymers), and initiator residues. The volume ratio of ethanol to water is 1:(0.8~1.2), for example, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

[0107] Preferably, the drying includes freeze drying or drying using supercritical CO2.

[0108] Fourthly, the present invention provides an application of the antibacterial porous material as described in the third aspect in biomedicine, daily chemical hygiene products, and water treatment.

[0109] Specifically, the antibacterial porous material can be used in the field of sanitary napkins, dressings, and other daily chemical hygiene products. Using one or more layers of antibacterial porous material made from an antibacterial high internal phase emulsion with the same or different pore sizes as the core of sanitary napkins, dressings, and other daily chemical hygiene products, the material achieves absorption, drainage, water retention, anti-backflow, or slow release of liquids such as moisture, menstrual blood, blood, body fluids, and nutrients through its high antibacterial properties, high porosity, high connectivity, and controllable pore size. This gives the product excellent properties such as thinness, dryness, long-lasting effect, slow release, and antibacterial properties.

[0110] This invention introduces CS (Chemical Solidification) for the preparation of PolyHIPEs materials, which has the following unique advantages:

[0111] (1) CS can destroy the cell membrane of microorganisms. When used to prepare PolyHIPEs materials, its antibacterial durability can be maintained at 98%, and it can be used for wound dressings and other applications.

[0112] (2) The CS block contains a large number of reactive sites, which can introduce carboxyl groups and covalently connect with St / DVB during the polymerization process, covalently bonding the entire triblock molecule to the final polymer network, solving the problem that PEG-PS is easily washed away by solvent when used as a stabilizer, and becoming the inherent and uniformly distributed reactive sites of the material.

[0113] (3) CS has a certain pH response. Under acidic conditions, it is protonated to generate electrostatic repulsion, which inhibits droplet aggregation.

[0114] Compared with the prior art, the present invention has the following beneficial effects:

[0115] This invention introduces a polyethylene glycol-polystyrene-chitosan triblock polymer (PEG-PS-CS) with antibacterial properties as an emulsifier into a high internal phase emulsion, achieving the following effects:

[0116] 1) Stabilizing the emulsion: The hydrophilic segments of PEG extend into the aqueous droplets, providing steric stabilization; the rigid segments of PS provide solubility and anchoring in the oil phase; the functional segments of CS provide pH responsiveness, antibacterial properties, and targeting; and the chain length of PEG / PS can be adjusted, allowing for precise control of emulsion stability.

[0117] 2) Improved strength of porous materials: CS blocks and PEG-PS are cross-linked through hydrogen bonds to form a composite network, significantly improving the mechanical strength of porous materials. The effect can reach: compressive modulus of porous materials ≥8MPa.

[0118] 3) Reduce surfactant usage: The triblock polymer acts as a small molecule surfactant, and the amount added is 1wt%~5wt% of the total mass of the oil phase monomers. It can stabilize more than 90% of the aqueous phase (while the amount added when using PEG-PS in the traditional way is 5wt%~15wt% of the total mass of the monomers).

[0119] 4) Long-lasting antibacterial function: The amino group (-NH3) of the CS block + The increased positive charge of the electrostatic charge causes it to bind more strongly to the bacterial cell wall, resulting in higher activity. Electrostatic interactions disrupt the bacterial cell membrane, leading to leakage of intracellular substances. Attached Figure Description

[0120] Figure 1 Fourier transform infrared spectrum of the PEG-PS-CS triblock copolymer synthesized in Preparation Example 1.

[0121] Figure 2 The image shows a SEM image of the antibacterial porous material provided in Example 1. Detailed Implementation

[0122] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0123] Unless otherwise specified, information on some of the raw materials used in the preparation examples, embodiments, and comparative examples of this invention is shown in Table 1 below:

[0124] Table 1

[0125]

[0126] Preparation Example 1

[0127] This preparation example provides a PEG-PS-CS triblock copolymer, the preparation method of which includes the following steps:

[0128] (1) Preparation of PEG 5000 Macromolecular RAFT reagent (mPEG-CTA)

[0129] Raw material: mPEG 5000 -OH (5.0 g, 1.0 mmol); CPADB (4-cyano-4-(phenylthiocarbonylthio)pentanoic acid, 0.42 g, 1.5 mmol); DCC (0.25 g, 1.2 mmol); DMAP (0.012 g, 0.1 mmol); anhydrous dichloromethane (DCM, 50 mL).

[0130] Steps: Add mPEG 5000-OH, CPADB, and DMAP were dissolved in 40 mL of anhydrous DCM and stirred in an ice bath. A DCM solution of DCC (10 mL) was added dropwise, and the reaction was carried out at room temperature for 24 h under nitrogen protection. The N,N'-dicyclohexylurea (DCU) precipitate was removed by filtration, and the filtrate was concentrated to 10 mL. The precipitate was added dropwise to 200 mL of cold diethyl ether, centrifuged (8000 rpm, 10 min), and dried under vacuum for 24 h to obtain a pale yellow waxy solid mPEG-CTA (4.8 g, yield 92%).

[0131] (2) RAFT polymerization to synthesize PEG 5000 -PS 15000 -CTA

[0132] Ingredients: mPEG-CTA (4.0 g, 0.8 mmol); styrene (St, 15.6 g, 150 mmol); AIBN (26.3 mg, 0.16 mmol); anhydrous toluene (40 mL).

[0133] Procedure: Dissolve mPEG-CTA, St, and AIBN in toluene, purge with nitrogen for 30 min, cycle through liquid nitrogen freezing, vacuuming, and nitrogen purging three times, seal, and react in an oil bath at 70℃ for 12 h (conversion >95%, GPC monitoring). Cool in an ice bath, and precipitate the reaction mixture dropwise into 500 mL of cold methanol / ether (1:1). Filter, wash the solid three times with ether, and dry under vacuum to obtain white solid PEG. 5000 -PS 15000 -CTA (17.2 g).

[0134] (3) Terminal azidation (PEG) 5000 -PS 15000 -N3)

[0135] Raw material: PEG 5000 -PS 15000 -CTA (5.0 g); n-Butylamine (5.0 mL, 50 mmol) as reducing agent; N-(2-azidoethyl)maleimide (N3-PEG-Mal, 0.095 g, 0.5 mmol) as azide reagent; anhydrous DMF (50 mL); diethyl ether (for precipitation).

[0136] Steps: ① Reduction reaction: PEG 5000 -PS 15000-CTA was dissolved in 40 mL of anhydrous DMF, and n-butylamine was added. The mixture was reacted at room temperature for 24 h under nitrogen protection to reduce the terminal trithiocarbonate to a thiol (-SH). Precipitation purification: The reaction solution was added dropwise to 500 mL of cold diethyl ether to precipitate the precipitate. The precipitate was centrifuged (8000 rpm, 10 min) and dried under vacuum to obtain PEG. 5000 -PS 15000 -SH (intermediate).

[0137] ② Azide reaction: PEG 5000 -PS 15000 -SH was dissolved in 40 mL of anhydrous DMF, and N3-PEG-Mal was added. The reaction was carried out under nitrogen protection at room temperature in the dark for 24 h. Precipitation purification: The reaction solution was added dropwise to 500 mL of cold water to precipitate, filtered, washed three times with water, and dried under vacuum to obtain PEG. 5000 -PS 15000 -N3 (4.5 g).

[0138] (4) Chitosan acetylation modification (Alkyne-CS)

[0139] Raw materials: chitosan (CS, Mw=20 kDa, degree of deacetylation 90%, 2.0 g); 5-hexynoic acid (0.18 g, 1.6 mmol); EDC·HCl (0.46 g, 2.4 mmol); NHS (0.28 g, 2.4 mmol); 0.1 mol / L acetate buffer (pH 5.5, 200 mL).

[0140] Procedure: Dissolve CS in acetate buffer, then add 5-hexyneic acid, EDC·HCl, and NHS, and stir at room temperature in the dark for 24 hours. Dialysis (MWCO 3.5 kDa): Day 1: Dialyze to 0.1 mol / L NaCl aqueous solution; Days 2-4: Dialyze to pure water. Afterwards, freeze-dry to obtain Alkyne-CS (1.8 g, degree of substitution 0.15).

[0141] (5) Click chemical coupling (PEG) 5000 -PS 15000 -CS)

[0142] Raw material: PEG 5000 -PS 15000 -N3 (1.0 g); Alkyne-CS (0.6 g); CuSO4·5H2O (12 mg, 0.048 mmol); Sodium ascorbate (NaAsc, 47 mg, 0.24 mmol); THPTA ligand (27 mg, 0.096 mmol); DMF / H2O = 7:3 (v / v, 30 mL).

[0143] Steps: Add PEG 5000 -PS 15000 -N3 was dissolved in 21 mL DMF, and Alkyne-CS was dissolved in 9 mL H2O (containing 1% acetic acid). The two solutions were mixed, and then CuSO4·5H2O, THPTA, and NaAsc were added. The mixture was stirred at room temperature in the dark under nitrogen protection for 36 h. Dialysis purification (MWCO 14 kDa): Day 1: Dialysis with DMF / H2O (7:3) containing 10 mmol / L EDTA; Days 2-3: Dialysis with pure water. Afterwards, the solution was freeze-dried to obtain a pale yellow solid PEG. 5000 -PS 15000 -CS (1.35 g).

[0144] The reaction formula for the PEG-PS-CS triblock copolymer provided in this preparation example is shown below:

[0145]

[0146] In the PEG-PS-CS triblock copolymer synthesized in this preparation example, the PEG block has a molecular weight of 2000-8000 Da and m=45-182; the PS block has a molecular weight of 10400-19200 Da and n=99-184; and the CS block has a molecular weight of 10-50 kDa and t=62-310.

[0147] The Fourier transform infrared spectrum of the PEG-PS-CS triblock copolymer synthesized in this preparation example is shown below. Figure 1 As shown, the characteristic peak of the PEG block (1100 cm⁻¹) is clearly visible in the infrared spectrum of PEG-PS-CS. -1 Strong and wide COC stretching vibration peaks, 2850-2950 cm⁻¹ -1 The saturated CH stretching vibration peak in the interval), and the characteristic peak of the PS block (705 cm⁻¹). -1 Strong out-of-plane bending vibration peaks of monosubstituted benzene rings (CH) at 1500 cm⁻¹ -1 The characteristic peaks of the nearby benzene ring C=C skeleton stretching vibrations and the characteristic peaks of the CS block (3200-3600 cm⁻¹) -1 Broad and strong OH and NH stretching vibration peaks, 1650 cm⁻¹ -1 The amide I band around the C=O stretching vibration peak, 1568 cm⁻¹ -1 The presence of NH bending and CN stretching coupling vibration peaks in the amide II band (left and right sides) confirms the integrity of the triblock structure; simultaneously, characteristic peaks of the 1,2,3-triazole ring (1520 cm⁻¹) are observed. -1C=N stretching vibration peak in the interval, 1255 cm -1 The presence of ring skeleton stretching vibration peaks in the region confirms the generation of triazole rings through click chemical coupling. These characteristics combined demonstrate the successful synthesis of the PEG-PS-CS triblock copolymer.

[0148] Preparation Example 2

[0149] The only difference between this preparation example and Preparation Example 1 is that the molecular weight of monomethoxy polyethylene glycol (mPEG-OH) is 2000, the amount used is 2.0 g, and the resulting block copolymer is PEG. 2000 -PS 15000 -CS.

[0150] Preparation Example 3

[0151] The only difference between this preparation example and preparation example 1 is that step (2) is different, as follows:

[0152] ① The amount of styrene was adjusted to 10.8g, 104mmol; ② The polymerization process was a 70℃ oil bath reaction for 15h; ③ The reaction solution was added dropwise to 500ml of cold methanol / ether (2:1) mixture to precipitate; other steps remained unchanged.

[0153] The PEG-PS-CS triblock copolymer obtained in this preparation example is PEG 5000 -PS 10400 -CS, the molecular weight of the PS segment is 10400.

[0154] Example 1

[0155] This embodiment provides an antibacterial high internal phase emulsion, which includes an oil phase and an aqueous phase;

[0156] The preparation method includes the following steps:

[0157] (1) Oil phase preparation

[0158] Formulation: Styrene (St, 7.2 g); Divinylbenzene (DVB, 1.8 g); BPO (benzoyl peroxide, 0.18 g); Antibacterial triblock polymer PEG 5000 -PS 15000 -CS (prepared in Preparation Example 1, 0.45 g).

[0159] Steps: Mix St, DVB, and BPO, vortex to dissolve, then add the block copolymer PEG. 5000 -PS 15000 -CS, sonicate at 60℃ for 30 min until a homogeneous and transparent solution is formed.

[0160] (2) Aqueous phase preparation

[0161] Formula: Mix CaCl2 (4.15 g) and deionized water (100 mL) to prepare a 0.375 mol / L CaCl2 aqueous solution;

[0162] (3) HIPE emulsification

[0163] Equipment: IKA T25 homogenizer (S25N-10G rotor)

[0164] Steps: Place the oil phase in a 200 mL beaker, pre-stir in a homogenizer (200 rpm), slowly add the aqueous phase (10 mL / min) to the oil phase, gradually increase the speed to 800 rpm, and continue homogenizing for 10 min to form a paste-like white HIPE.

[0165] The volume ratio of the oil phase to the water phase is 1:10.

[0166] This embodiment also provides an antibacterial porous material, the preparation method of which includes the following steps:

[0167] The above-mentioned HIPE was injected into a Teflon mold (⌀ 20 mm × 50 mm), sealed, and polymerized in an oven at 75°C for 12 h. After cooling to room temperature, it was demolded and extracted by Soxhlet extraction with ethanol / water (1:1) for 48 h. It was then freeze-dried (-50°C, 24 h) to obtain a white porous material, which is the antibacterial porous material.

[0168] The SEM image of the antibacterial porous material provided in this embodiment is as follows: Figure 2 As shown, this porous material has a highly interconnected open pore structure.

[0169] Examples 2-7

[0170] The only difference from Example 1 is that the types and / or amounts of raw materials are different, as shown in Table 2.

[0171] Table 2

[0172]

[0173] Comparative Example 1

[0174] The only difference between this comparative example and Example 1 is that the PEG in step (1) is changed. 5000 -PS 15000 -CS was replaced with an equal mass of PEG-CS block polymer.

[0175] The PEG-CS block polymer was prepared by the following method:

[0176] (1) Preparation of alkynylated PEG (Alkyne-PEG)

[0177] Raw material: mPEG 5000 -OH (5.0 g, 1.0 mmol); Pentynoic acid (0.112 g, 1.2 mmol); DCC (0.247 g, 1.2 mmol); DMAP (0.012 g, 0.1 mmol); Anhydrous dichloromethane (DCM, 50 mL); Anhydrous diethyl ether (200 mL)

[0178] Steps: Add mPEG 5000 -OH and pentynic acid were dissolved in 50 mL of anhydrous DCM and cooled in an ice bath. DMAP was added and stirred until homogeneous. DCC was dissolved in 10 mL of anhydrous DCM and slowly added dropwise to the reaction system. The ice bath was removed, and the reaction was stirred for 24 hours at room temperature under nitrogen protection. The resulting DCC precipitate was removed by filtration, and the filtrate was concentrated to approximately 10 mL. The precipitate was added dropwise to 200 mL of ice-cold anhydrous diethyl ether, filtered, and washed three times with cold diethyl ether. The precipitate was dried under vacuum for 24 hours to obtain a white waxy solid, Alkyne-PEG (yield approximately 90%).

[0179] (2) Synthesis of azide-modified chitosan (N3-CS)

[0180] Raw materials: Chitosan (CS, Mw=20 kDa, degree of deacetylation 90%, 2.0 g); 2-iminothione hydrochloride (0.3 g, 2.0 mmol); N-(2-azidoethyl)maleimide (0.38 g, 2.0 mmol); 0.1 mol / L PBS buffer (pH 7.4, 200 mL); 1% acetic acid solution (100 mL); dialysis bag (MWCO: 3.5 kDa).

[0181] Steps: Chitosan thiolation: Dissolve CS in 100 mL of 1% acetic acid solution and stir until completely dissolved. Add 2-iminothione hydrochloride and adjust the pH to 7.0-7.5 with NaOH. React at room temperature in the dark for 12 hours to obtain thiolated chitosan (CS-SH). Azide reaction: Dissolve N-(2-azidoethyl)maleimide in 10 mL of PBS buffer. Slowly add it dropwise to the CS-SH solution, maintaining the pH at 7.0-7.5. React at room temperature in the dark for 24 hours, introducing azido groups through the click reaction of maleimide with thiols.

[0182] Purification: The reaction solution was transferred to a dialysis bag and dialyzed against 0.1 M NaCl aqueous solution for 2 days, followed by dialyzed against ultrapure water for 3 days. The solution was then freeze-dried to obtain N3-CS.

[0183] (3) Preparation of PEG by click chemical coupling (CuAAC) 5000 -CS

[0184] Raw materials: Alkyne-PEG (2.5 g, approx. 0.5 mmol alkynyl); N3-CS (1.0 g); CuSO4·5H2O (0.012 g, 0.048 mmol); sodium ascorbate (NaAsc, 0.047 g, 0.24 mmol); THPTA ligand (0.027 g, 0.096 mmol); DMF (15 mL); ultrapure water (15 mL, with 1% acetic acid for dissolution); dialysis bag (MWCO: 10-14 kDa).

[0185] Procedure: Dissolve Alkyne-PEG in 15 mL DMF; dissolve N3-CS in 15 mL ultrapure water (containing 1% acetic acid). Mix the two solutions, add CuSO4·5H2O and THPTA ligand, and stir until homogeneous. Quickly add sodium ascorbate; the system color changes from blue to brownish-red. React vigorously for 36 hours under nitrogen protection, at room temperature, and in the dark. Transfer the mixture to a dialysis bag, dialyze against a DMF / H2O (1:1) mixture containing 10 mmol EDTA for 2 days, then dialyze against ultrapure water for 3 days. Freeze-dry to obtain PEG. 5000 -CS diblock copolymer.

[0186] Comparative Example 2

[0187] The only difference between this comparative example and Example 1 is that the PEG in step (1) is changed. 5000 -PS 15000 -CS was replaced with an equal mass of PEG-PS block polymer.

[0188] The PEG-PS block polymer was prepared by the following method:

[0189] (1) Preparation of PEG 5000 Macromolecular RAFT reagent (mPEG-CTA)

[0190] The synthesis method was exactly the same as that in Preparation Example 1, yielding a pale yellow waxy solid mPEG. 5000 -CTA.

[0191] (2) RAFT polymerization to synthesize PEG 5000 -PS 15000

[0192] PEG-CTA (4.0 g, ~0.8 mmol), styrene (15.6 g, 150 mmol), and AIBN (0.026 g, 0.16 mmol) were dissolved in 40 mL of anhydrous toluene. The mixture was deoxygenated by three cycles of liquid nitrogen freezing, vacuuming, and nitrogen purging, and then sealed. The reaction was carried out in a 70°C oil bath for 15 hours (conversion was monitored by sampling). The reaction was terminated in an ice bath, and 10 mL of anhydrous THF was added to the reaction solution, followed by nitrogen or argon purging. 10 mL of n-butylamine was added, and the mixture was stirred at room temperature for 12 hours. When the color of the reaction solution changed from pale yellow (the color of CTA) to colorless or milky white, the reaction solution was added dropwise to 500 mL of cold methanol / ether (1:1, v / v) mixture to precipitate. The precipitate was filtered, washed three times with ether, and dried under vacuum to obtain a white solid PEG. 5000 -PS 15000 .

[0193] Comparative Example 3

[0194] The only difference between this comparative example and Example 1 is that the PEG in step (1) is changed. 5000 -PS 15000 -CS is replaced with the traditional surfactant SPAN80, at a dosage of 1.35g.

[0195] The antibacterial porous materials provided in the embodiments and comparative examples of the present invention were subjected to performance tests, and the test methods are as follows:

[0196] (1) HIPE emulsion stability test

[0197] Static stability observation: The prepared HIPE was placed at a constant temperature (room temperature 25℃), and the time of layering (aqueous phase precipitation > 5%) was observed and recorded periodically.

[0198] (2) Scanning electron microscopy (SEM) analysis:

[0199] The cross-section of the antibacterial porous material provided in Example 1 was observed using a scanning electron microscope (SEM). The diameter of 100 pores was measured, and the average pore diameter D50 was calculated.

[0200] (3) Porosity test: The ethanol replacement method was used for the test.

[0201] The porosity of the porous materials provided in the test examples and comparative examples was specifically tested using the following method: the dry porous material was weighed (m1) using the liquid displacement method, then immersed in anhydrous ethanol until saturated, removed, the surface ethanol was wiped dry, and the material was weighed again (m2). .

[0202] (4) Compression stress-strain test:

[0203] The MTS universal tensile tester was used for testing. The antibacterial porous material was cut into 10mm×10mm×10mm cubic specimens and compressed at 25℃ and a compression rate of 1mm / min. The stress-strain curve was obtained, and the compressive modulus was calculated by taking the slope of the linear segment of strain 2%-8%. The test results were taken as the average value of 3 parallel specimens.

[0204] (5) Antibacterial test: Surface contact bactericidal test

[0205] Test bacteria were introduced onto the surface of the antibacterial porous material, and after cultivation and elution, the sterilization rate was calculated using a formula:

[0206] Material preparation: Cut the antibacterial porous material into 10×10×1 mm pieces. 3 thin slices;

[0207] Bacterial culture: Staphylococcus aureus, Escherichia coli; bacterial concentration: 1×10⁻⁶ 5 CFU / mL (PBS buffer);

[0208] Contact experiment: The material was immersed in 1 mL of bacterial solution and incubated at 37°C. After 24 h, the material was washed off and the inhibition rate was calculated.

[0209] The calculation formula is: .

[0210] The performance test results are shown in Table 3.

[0211] Table 3

[0212]

[0213] As shown in Table 3, the high internal phase emulsions provided in Examples 1-7 of this invention all exhibit high stability (55-78 h), and the prepared porous materials have high porosity (92%-94%) and high compressive modulus (6.8-10.3 MPa), while also demonstrating good antibacterial properties (the porous materials show an antibacterial rate of over 90% against Staphylococcus aureus and Escherichia coli). The improvement in compressive modulus stems from the synergistic enhancement mechanism of the CS block and PEG-PS: the PS block provides rigid support, the PEG block forms an elastic network, and the CS block dissipates energy through hydrogen bonds.

[0214] In Comparative Example 1, the PEG-CS block polymer is hydrophilic and difficult to stabilize W / O type emulsions. HIPE has poor stability. The high specific surface area of ​​CS makes the material itself have a high specific surface area. CS is directly exposed, resulting in antibacterial properties that are not as stable as triblock polymers.

[0215] In Comparative Example 2, lacking the steric hindrance and electrostatic repulsion provided by CS, the stability of PEG-PS alone was poor, and it completely lacked antibacterial function, with an antibacterial rate of <10% and an almost zero antibacterial band at the cross-section. The mechanical properties were far lower than those of the examples, demonstrating that CS can enhance mechanical properties through interfacial interactions and composite cross-linking.

[0216] Comparative Example 3: Using the traditional surfactant SPAN80 as the emulsifier for HIPE, with an addition amount of 15%, and other conditions remaining unchanged, the prepared porous material had almost no antibacterial properties, and in order to achieve system stability, the amount of surfactant added needed to reach 15%. Due to the high amount of surfactant added and the lack of anchoring with other chemical bonds, the strength of the prepared foam was only that of ordinary porous materials.

[0217] The applicant declares that the present invention is illustrated by the above embodiments to demonstrate the antibacterial high internal phase emulsion, its preparation method, and its application. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high-inner-phase antibacterial emulsion, characterized in that, The antibacterial high internal phase emulsion comprises an oil phase and an aqueous phase; The oil phase includes polymeric monomers, crosslinking agents, and emulsifiers; The aqueous phase includes water and electrolytes; The emulsifier is a hydrophilic-hydrophobic-antibacterial triblock polymer; The hydrophilic-hydrophobic-antibacterial triblock polymer is a polyethylene glycol-polystyrene-chitosan triblock polymer; At least one of the oil phase and the aqueous phase includes an initiator.

2. The antibacterial high internal phase emulsion according to claim 1, characterized in that, The polyethylene glycol-polystyrene-chitosan triblock polymer was prepared by the following method: (1) Mix monomethoxy polyethylene glycol, chain transfer agent, first activator and solvent, cool in an ice bath, then add a mixture of second activator and solvent, react, and post-process to obtain mPEG-CTA; (2) Mix the mPEG-CTA, styrene, initiator and solvent, react, and post-process to obtain mPEG-PS-CTA; (3) Mix the mPEG-PS-CTA with a solvent, then add a reducing agent, perform the first reaction, and perform the first post-treatment to obtain mPEG-PS-SH; The mPEG-PS-SH was mixed with a solvent, then an azide reagent was added, followed by a second reaction and a second post-treatment to obtain PEG-PS-N3. (4) Mix chitosan and acetate buffer, then add organic acid and activator, react, and post-process to obtain Alkyne-CS; (5) Mix the PEG-PS-N3 with an organic solvent to obtain a PEG-PS-N3 solution, mix the Alkyne-CS with an aqueous acetic acid solution to obtain an Alkyne-CS solution, mix the PEG-PS-N3 solution and the Alkyne-CS solution, then add a catalyst and optionally a ligand, react, and post-process to obtain PEG-PS-CS, which is the polyethylene glycol-polystyrene-chitosan triblock polymer.

3. The antibacterial high internal phase emulsion according to claim 2, characterized in that, The number-average molecular weight of the monomethoxy polyethylene glycol in step (1) is 2000~5000 Da; Preferably, the chain transfer agent in step (1) comprises 4-cyano-4-(phenylthiocarbamoylthio)pentanoic acid; Preferably, in step (1), the first activator comprises 4-dimethylaminopyridine; Preferably, in step (1), the second activator comprises N,N'-dicyclohexylcarbodiimide; Preferably, the molar ratio of monomethoxy polyethylene glycol, chain transfer agent, first activator, and second activator in step (1) is 1:(1.2~1.5):(0.05~0.2):(1.2~1.5); Preferably, the solvent in step (1) includes dichloromethane; Preferably, the reaction temperature in step (1) is 20~30℃ and the reaction time is 20~30 hours; Preferably, the post-processing in step (1) includes filtration, concentration, centrifugation, and vacuum drying; Preferably, the initiator in step (2) comprises azobisisobutyronitrile; Preferably, the molar ratio of mPEG-CTA, styrene, and initiator in step (2) is 1:(150~250):(0.1~0.5); Preferably, the solvent in step (2) includes toluene; Preferably, the reaction temperature in step (2) is 65~75℃ and the reaction time is 6~24 hours; Preferably, the post-processing in step (2) includes precipitation, filtration, and drying.

4. The antibacterial high internal phase emulsion according to claim 2 or 3, characterized in that, The solvent in step (3) includes N,N-dimethylformamide; Preferably, the reducing agent in step (3) includes n-butylamine; Preferably, the mass ratio of mPEG-PS-CTA to reducing agent in step (3) is 1:(1~1.5); Preferably, the temperature of the first reaction in step (3) is 20~30℃, and the time of the first reaction is 20~30h; Preferably, the first post-treatment in step (3) includes precipitation, centrifugation, and drying; Preferably, the azide reagent in step (3) comprises N-(2-azidoethyl)maleimide; Preferably, the molar ratio of mPEG-PS-CTA and azide reagent in step (3) is 1:(1~2); Preferably, the temperature of the second reaction in step (3) is 20~30℃, and the time of the second reaction is 20~30h; Preferably, the second post-processing in step (3) includes precipitation, filtration, washing, and drying; Preferably, the degree of deacetylation of the chitosan in step (4) is >85%, and the weight-average molecular weight is 10-50 kDa; Preferably, the concentration of the acetate buffer solution in step (4) is 0.05~0.2 mol / L; Preferably, the organic acid in step (4) includes pentynic acid and / or 5-hexynic acid; Preferably, the activator in step (4) comprises N-hydroxysuccinimide and / or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; Preferably, the molar ratio of chitosan, organic acid, and activator in step (4) is 1:(10~20):(40~60); Preferably, the reaction temperature in step (4) is 20~30℃ and the reaction time is 20~30 hours; Preferably, the reaction in step (4) is carried out under light-protected conditions; Preferably, the post-processing in step (4) includes dialysis and freeze-drying.

5. The antibacterial high internal phase emulsion according to any one of claims 2-4, characterized in that, The molar ratio of PEG-PS-N3 and Alkyne-CS in step (5) is 1:(0.8~1.2); Preferably, the organic solvent in step (5) includes N,N-dimethylformamide; Preferably, the concentration of the acetic acid aqueous solution in step (5) is 0.5% to 2%; Preferably, the volume ratio of the organic solvent to the aqueous acetic acid solution in step (5) is (6~8):(2~4); Preferably, the catalyst in step (5) comprises CuSO4·5H2O and / or sodium ascorbate; Preferably, the ligand in step (5) comprises any one or a combination of at least two of the following: tris(3-hydroxypropyltriazolylmethyl)amine, tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine, and pentamethyldiethylenetriamine; Preferably, the molar ratio of PEG-PS-N3 to catalyst in step (5) is 1:(0.5~0.7); Preferably, the molar ratio of PEG-PS-N3 to the ligand in step (5) is 1:(0.1~0.3); Preferably, the reaction temperature in step (5) is 20~30℃ and the reaction time is 24~48 hours; Preferably, the reaction in step (5) is carried out under light-protected conditions; Preferably, the post-processing in step (5) includes dialysis and freeze-drying.

6. The antibacterial high internal phase emulsion according to any one of claims 1-5, characterized in that, The polymerizing monomers include any one or a combination of at least two of vinyl monomers, acrylate monomers, or methacrylate monomers; Preferably, the polymerizable monomers include any one or a combination of at least two of the following: styrene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, methyl methacrylate, butyl acrylate, octadecyl acrylate, ethylhexyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, tetradecyl acrylate, benzyl acrylate, nonylphenyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, and octadecyl methacrylate. Preferably, the crosslinking agent comprises a multifunctional crosslinking monomer; Preferably, the crosslinking agent comprises any one or a combination of at least two of the following: divinylbenzene, acrylates containing at least two double bonds, and monomers containing methacrylate groups; Preferably, the crosslinking agent comprises any one or a combination of at least two of the following: divinylbenzene, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,12-dodecyl dimethacrylate, 1,14-tetradecanediol dimethacrylate, ethylene glycol dimethacrylate, neopentyl glycol diacrylate (2,2-dimethylpropylene glycol diacrylate), hexanediol acrylate methacrylate, and sorbitol pentaacrylate. Preferably, the initiator in the oil phase includes a photoinitiator and / or a thermal initiator; Preferably, the photoinitiator comprises any one or a combination of at least two of photoinitiator 819, benzyl ketal, α-hydroxyalkyl phenyl ketone, α-aminoalkyl phenyl ketone, and acylphosphine oxide; Preferably, the thermal initiator comprises benzoyl peroxide; Preferably, in the oil phase, the mass ratio of the polymeric monomer to the crosslinking agent is (1~20):1; Preferably, in the oil phase, the amount of the emulsifier is 1% to 10% of the sum of the mass of the polymeric monomer and the crosslinking agent, more preferably 1% to 5%. Preferably, in the oil phase, the amount of the initiator is 0% to 10% of the sum of the mass of the polymerizing monomer and the crosslinking agent.

7. The antibacterial high internal phase emulsion according to any one of claims 1-6, characterized in that, The electrolyte includes sodium chloride and / or calcium chloride; Preferably, the concentration of the electrolyte in the aqueous phase is 0.01~1 mol / L; Preferably, the initiator in the aqueous phase includes any one or a combination of at least two of persulfates, azo compounds, redox pairs, and water-soluble photoinitiators; Preferably, based on the total mass of the aqueous phase being 100%, the amount of initiator in the aqueous phase is 0% to 10%; Preferably, the volume ratio of the oil phase to the water phase is 1:(4~45), more preferably 1:(10~25).

8. A method for preparing an antibacterial high internal phase emulsion as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: (S1) Mix the polymer monomer, crosslinking agent, and optionally initiator, then add emulsifier and mix again to obtain the oil phase; (S2) Water and electrolyte, and optionally an initiator, are mixed to obtain an aqueous phase; (S3) Add the aqueous phase to the oil phase and mix to obtain the antibacterial high internal phase emulsion; Wherein, at least one of the oil phase and the aqueous phase includes an initiator; Preferably, the mixing in step (S1) includes magnetic stirring; Preferably, the remixing in step (S1) includes ultrasonic dispersion or vigorous stirring; Preferably, the mixing in step (S3) includes any one of homogenization, ultrasonication, and stirring; Preferably, the homogenization speed is 500~1000 rpm, the homogenization time is 5~15 min, and the system temperature during the homogenization process is 20~30℃.

9. An antibacterial porous material, characterized in that, The antibacterial porous material is prepared from the antibacterial high internal phase emulsion according to any one of claims 1-7; Preferably, the antibacterial porous material is prepared by the following method: An antibacterial high internal phase emulsion was added to a mold and cured. The cured product was then extracted and freeze-dried to obtain the antibacterial porous material. Wherein, the antibacterial high internal phase emulsion includes the antibacterial high internal phase emulsion as described in any one of claims 1-7; Preferably, the curing temperature is 70~90℃, and the curing time is 4~24 hours; Preferably, the solvent used for extraction includes a mixture of ethanol and water; Preferably, the drying includes freeze drying or drying using supercritical CO2.

10. The application of the antibacterial porous material as described in claim 9 in biomedicine, daily chemical hygiene products, and water treatment.

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