Preparation method and application of polyion liquid-based antibacterial material

Abstract

The invention belongs to the technical field of macromolecular antibacterial materials, and particularly relates to a preparation method and application of a polyion liquid-based antibacterial material. The structural composition and formula of the polyion liquid-based antibacterial material are uniquely designed, and the preparation method comprises the following steps: synthesizing a series of ionic liquid monomers containing alkyl side chains by adopting a one-step method, and preparing the polyion liquid-based antibacterial material by adopting a reversible addition-fragmentation chain transfer (RAFT) polymerization method. A series of polyionic liquid materials with adjustable microstructure and macroscopic performance are constructed by regulating and controlling the structure of an RAFT reagent, the length of a cationic alkyl side chain of an ionic liquid monomer, the monomer feed ratio and polymerization reaction conditions. The prepared polyion liquid-based antibacterial material has a good antibacterial effect on staphylococcus aureus, the antibacterial performance is lasting, the antibacterial effect of the polyion liquid copolymer is the best, and the polyion liquid-based antibacterial material is an ideal macromolecular antibacterial material.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer antibacterial materials, and in particular relates to a preparation method and application of a polyionic liquid-based antibacterial material. Background Art

[0002] Bacterial infections have long threatened human health, and the increasing incidence of bacterial drug resistance has been troubling researchers, making treatment increasingly difficult. Therefore, developing highly effective antimicrobial agents that do not induce drug resistance is imperative.

[0003] The mechanisms of action of antimicrobial agents primarily include inhibiting cell metabolism and disrupting internal and external cellular structures. Recently, polyionic liquids (PILs) have attracted the attention of researchers due to their exceptional spectrum of antimicrobial properties. Their exceptional biocompatibility also provides a solid foundation for their application in the fields of biomaterials and bioengineering. PILs are polymerized products of small molecule ionic liquids. Each repeating unit contains ionic liquid monomers, linked by polymer chains to form a polymer network structure. PILs typically possess stronger antimicrobial properties than their corresponding monomers, exceeding the combined effects of individual ionic liquids. Due to the linkages within the PIL, each ionic liquid acts on the aggregated area, causing localized cell membrane ruptures, an effect that is lethal to bacteria. While retaining the highly effective antimicrobial properties of ionic liquids, PILs also mitigate the low utilization of ionic liquid functional groups, demonstrating enormous potential for application in the field of novel antimicrobial materials.

[0004] Due to their unique design, processability, and structure, polyionic liquids (PILs) possess broad antimicrobial properties, demonstrating high bactericidal rates against most bacteria and some superbugs. Currently, the main factors influencing the antimicrobial activity of PILs include charge density, alkyl chain length and position, counterions, molecular weight, and polymer segment sequence. Therefore, the rational design and synthesis of PILs with defined chemical structures and active sites, as well as the clarification of the structure-activity relationship between structure and antimicrobial activity, remain key challenges for PILs. Summary of the Invention

[0005] In response to the above-mentioned problems, the present invention provides a method for preparing a polymer antibacterial material based on polyionic liquid. Traditional imidazole-type and quaternary ammonium salt-type polymer antibacterial materials are combined, and a RAFT polymerization method is adopted to prepare a series of ionic liquid homopolymers and copolymers with adjustable molecular weight, narrow molecular weight distribution, and controllable sequence structure by regulating conditions such as the structure of the RAFT agent, the type of ionic liquid monomer cation, the length of the alkyl side chain, and the monomer feed ratio. That is, a series of polyionic liquid antibacterial materials with adjustable microstructure and macroscopic properties are prepared, which optimizes the structure and performance of traditional single-component antibacterial materials, combines antibacterial properties and biocompatibility, and provides a new generation of solutions for the prevention and control of drug-resistant bacterial infections.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A polyionic liquid-based antibacterial material is a polyionic liquid homopolymer or a polyionic liquid copolymer; the polyionic liquid copolymer is a polyionic liquid copolymer with a random structure or a polyionic liquid copolymer with a block structure.

[0008] The preparation method of the polyionic liquid homopolymer is as follows: dissolving an ionic liquid monomer, a free radical initiator and a RAFT chain transfer agent in an organic solvent to form a uniform mixed solution, transferring the mixed solution into an ampoule, replacing the atmosphere with nitrogen, carrying out a polymerization reaction under heating conditions, and after the reaction is completed, using an organic solvent for sedimentation and washing, and drying to a constant weight to obtain the polyionic liquid homopolymer.

[0009] The preparation method of the random-structured polyionic liquid copolymer is as follows: under a nitrogen atmosphere, two ionic liquid monomers dissolved in an organic solvent are uniformly mixed to obtain a monomer mixed solution; a RAFT chain transfer agent and a free radical initiator are dissolved in the organic solvent, the obtained mixed solution is added to the monomer mixed solution, a polymerization reaction is carried out under heating conditions, and after the polymerization is completed, the polymerization is purified and dried to obtain the random-structured polyionic liquid copolymer.

[0010] The preparation method of the block-structured polyionic liquid copolymer is as follows: under a nitrogen atmosphere, an ionic liquid monomer is dissolved in an organic solvent to obtain a monomer solution; a RAFT chain transfer agent and a free radical initiator are dissolved in the organic solvent, the obtained mixed solution is added to the monomer solution, a polymerization reaction is carried out under heating conditions, another ionic liquid monomer is added after the polymerization reaction is completed, and the polymerization reaction is continued. After the polymerization is completed, the copolymer is purified and dried to obtain the block-structured polyionic liquid copolymer.

[0011] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the chemical structural formula of the ionic liquid monomer is any one of (I), (II), (III) and (IV):

[0012]

[0013] Among them, X1 - 、X2 - 、X3 - and X4 - All Cl - Br - , I - Any one of; R1, R2, R3 and R4 are all alkyl C n H 2n+1 , n ranges from 1 to 16.

[0014] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, in the method for preparing the polyionic liquid homopolymer, the total concentration of the ionic liquid monomer in the mixed solution is 0.5-1.0 mol / L.

[0015] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, in the preparation method of the random-structured polyionic liquid copolymer and the block-structured polyionic liquid copolymer, the molar ratio of the two ionic liquid monomers is 1:100 to 100:1.

[0016] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the free radical initiator is any one of azobisisobutyronitrile, azobiscyanovaleric acid, ammonium persulfate, and potassium persulfate.

[0017] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the RAFT chain transfer agent is any one of 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid, 4-cyano-4-[[(dodecylthio)thioketonemethyl]thio]pentanoic acid, and S,S-dibenzyl trithiocarbonate.

[0018] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the molar ratio of the RAFT chain transfer agent to the total amount of the ionic liquid monomer is 1:200 to 1:20.

[0019] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the organic solvent used to dissolve the ionic liquid monomer, the free radical initiator or the RAFT chain transfer agent is an organic solvent with a boiling point of 80 to 160°C.

[0020] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the organic solvent used for sedimentation and washing is an organic solvent with a boiling point of 40 to 80°C.

[0021] Furthermore, the drying temperature of the above-mentioned polyionic liquid-based antibacterial material is 40-80°C.

[0022] Furthermore, in the above-mentioned polyionic liquid-based antibacterial material, the heating temperature of the polymerization reaction is 50-80° C., and the reaction time is 24-48 hours.

[0023] Application of any one of the above-mentioned polyionic liquid-based antibacterial materials in the antibacterial field.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention provides a method for preparing polyionic liquid-based antimicrobial materials. This innovative method utilizes reversible addition-fragmentation chain transfer (RAFT) polymerization to effectively control the molecular weight of the polyionic liquid, achieving monodispersity. By adjusting the order of monomer addition, the polyionic liquid sequence structure (block or random) can be effectively controlled. This method is simple, easy to operate, and universally applicable, providing clear guidance for the preparation of precisely structured polyionic liquid antimicrobial agents.

[0026] 2. The present invention provides a precisely controllable polyionic liquid-based antibacterial material. By regulating the structure of the RAFT agent, the length of the cationic alkyl side chain of the ionic liquid monomer, the monomer feed ratio and the polymerization reaction conditions, the charge density and hydrophilic and hydrophobic properties of the polyionic liquid are effectively regulated, thereby achieving effective binding to Staphylococcus aureus and achieving the antibacterial purpose.

[0027] 3. The preparation method of the polyionic liquid-based antibacterial material provided by the present invention innovatively combines traditional imidazole-type and quaternary ammonium salt-type polymer antibacterial materials, and realizes the synergistic optimization of antibacterial properties by copolymerization modification through regulating the length of the alkyl side chain and the ratio of raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The monomers [VImC4][Br], [DM-C4][Br] and their copolymer PVIm-DM in Example 14 are 1:1 of 1 H NMR spectrum.

[0029] Figure 2 These are static water contact angle test diagrams of imidazole-type polyionic liquid homopolymers, including (a) PVIm-4; (b) PVIm-8; (c) PVIm-12.

[0030] Figure 3 This is the colony growth of Staphylococcus aureus on LB agar plates in different experimental groups in Example 20.

[0031] Figure 4 is the survival rate of Staphylococcus aureus under different concentration gradients of polyionic liquid-based antibacterial materials in Example 20. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, the preferred experimental scheme of the present invention is described below in conjunction with the embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention rather than limiting the claims of the present invention.

[0033] (1) Synthesis of polyionic liquid homopolymers

[0034] Example 1 Synthesis of 1-vinyl-3-butylimidazolium bromide ([VImC4][Br]) homopolymer

[0035] The structural formula of [VImC4][Br] is shown in (V). [VImC4][Br] monomer (2.3113 g, 10 mmol), azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol), and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropanoic acid (0.0729 g, 0.2 mmol) were dissolved in 15 mL of DMF at room temperature and thoroughly stirred to obtain a uniform mixed solution. This mixed solution was then added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove dissolved oxygen. The ampoule was then heated and stirred in a 70°C oil bath for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed multiple times with ethyl acetate to remove unreacted monomers. The product was then dried under vacuum at 55°C for 24 hours to obtain the homopolymer P[VImC4][Br] (PVIm-4).

[0036]

[0037] Example 2 Synthesis of 1-vinyl-3-octylimidazolium bromide ([VImC8][Br]) homopolymer

[0038] The structural formula of [VImC8][Br] is shown in (VI). [VImC8][Br] monomer (2.8724 g, 10 mmol), azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol), and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropanoic acid (0.0729 g, 0.2 mmol) were dissolved in 15 mL of DMF at room temperature and thoroughly stirred to obtain a uniform mixed solution. This mixed solution was then added to a 50 mL ampoule and bubbling with nitrogen through a double-row tube to remove dissolved oxygen. The ampoule was then heated and stirred in an oil bath at 70°C for 24 h. After the reaction, the product was precipitated with ethyl acetate and washed multiple times with ethyl acetate to remove unreacted monomers. The product was then dried under vacuum at 55°C for 24 h to obtain the homopolymer P[VImC8][Br] (PVIm-8).

[0039]

[0040] Example 3 1-vinyl-3-dodecyl imidazolium bromide ([VImC 12 Synthesis of ][Br]) homopolymer

[0041] [VImC 12 The structural formula of ][Br] is as shown in (VII). At room temperature, [VImC 12][Br] monomer (3.4335 g, 10 mmol), azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 15 mL of DMF and stirred thoroughly to obtain a uniform mixed solution. The mixed solution was added to a 50 mL ampoule and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70 ° C oil bath and heated with stirring for 24 h. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove the unreacted monomers. It was then dried under vacuum at 55 ° C for 24 h to obtain the homopolymer P[VImC 12 ][Br](PVIm-12).

[0042]

[0043] Example 4 Synthesis of Methacryloyloxyethyl Dimethylbutylammonium Bromide ([DM-C4][Br]) Homopolymer

[0044] The structural formula of [DM-C4][Br] is shown in (VIII). [DM-C4][Br] monomer (2.9423 g, 10 mmol), azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol), and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropanoic acid (0.0729 g, 0.2 mmol) were dissolved in 15 mL of DMF at room temperature and thoroughly stirred to obtain a uniform mixed solution. This mixed solution was then added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove dissolved oxygen. The ampoule was then heated and stirred in an oil bath at 70°C for 24 h. After the reaction, the product was precipitated with ethyl acetate and washed multiple times with ethyl acetate to remove unreacted monomers. The product was then dried under vacuum at 55°C for 24 h to obtain the homopolymer P[DM-C4][Br] (PDM-4).

[0045]

[0046] Example 5 Synthesis of Methacryloyloxyethyl Dimethyloctylammonium Bromide ([DM-C8][Br]) Homopolymer

[0047] The structural formula of [DM-C8][Br] is shown in (IX). [DM-C8][Br] monomer (3.5033 g, 10 mmol), azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol), and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropanoic acid (0.0729 g, 0.2 mmol) were dissolved in 15 mL of DMF at room temperature and thoroughly stirred to obtain a uniform mixed solution. The mixed solution was then added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove dissolved oxygen. The ampoule was then placed in a 70°C oil bath with heating and stirring for 24 h. After the reaction, the product was precipitated with ethyl acetate and washed multiple times with ethyl acetate to remove unreacted monomers. The product was then dried under vacuum at 55°C for 24 h to obtain the homopolymer P[DM-C8][Br] (PDM-8).

[0048]

[0049] Example 6 Methacryloyloxyethyl dimethyl dodecyl ammonium bromide ([DM-C 12 Synthesis of ][Br]) homopolymer

[0050] [DM-C 12 The structural formula of ][Br] is as follows (X). At room temperature, [DM-C 12 ][Br] monomer (4.0644 g, 10 mmol), azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 15 mL of DMF and stirred thoroughly to obtain a uniform mixed solution. The mixed solution was added to a 50 mL ampoule and nitrogen was bubbled through a double-row tube to remove the internal dissolved oxygen. The ampoule was placed in a 70 ° C oil bath and heated with stirring for 24 h. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove the unreacted monomers. It was then dried under vacuum at 55 ° C for 24 h to obtain the homopolymer P[DM-C 12 ][Br](PDM-12).

[0051]

[0052] (2) Synthesis of polyionic liquid copolymers

[0053] Example 7 Synthesis of a random structured [VImC4][Br]:[VImC8][Br]=1:5 copolymer

[0054] At room temperature, [VImC4][Br] monomer (0.3852 g, 1.67 mmol) and [VImC8][Br] monomer (2.3937 g, 8.33 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-co-[VImC8]Br 1:5 ).

[0055] Example 8 Synthesis of a random structured [VImC4][Br]:[VImC8][Br]=1:1 copolymer

[0056] At room temperature, [VImC4][Br] monomer (1.1557 g, 5 mmol) and [VImC8][Br] monomer (1.4362 g, 5 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-co-[VImC8]Br 1:1 ).

[0057] Example 9 Synthesis of a random structured [VImC4][Br]:[VImC8][Br]=5:1 copolymer

[0058] At room temperature, [VImC4][Br] monomer (1.9261 g, 8.33 mmol) and [VImC8][Br] monomer (0.4787 g, 1.67 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-co-[VImC8]Br 5:1 ).

[0059] Example 10 Synthesis of a random structured [DM-C4][Br]:[DM-C8][Br]=1:5 copolymer

[0060] At room temperature, [DM-C4][Br] monomer (0.4904 g, 1.67 mmol) and [DM-C8][Br] monomer (2.9194 g, 8.33 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([DM-C4]Br-co-[DM-C8]Br 1:5 ).

[0061] Example 11 Synthesis of a random structured [DM-C4][Br]:[DM-C8][Br]=1:1 copolymer

[0062] At room temperature, [DM-C4][Br] monomer (1.4712 g, 5 mmol) and [DM-C8][Br] monomer (1.7517 g, 5 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([DM-C4]Br-co-[DM-C8]Br 1:1 ).

[0063] Example 12 Synthesis of a random structured [DM-C4][Br]:[DM-C8][Br]=5:1 copolymer

[0064] At room temperature, [DM-C4][Br] monomer (2.4519 g, 8.33 mmol) and [DM-C8][Br] monomer (0.5839 g, 1.67 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([DM-C4]Br-co-[DM-C8]Br 5:1 ).

[0065] Example 13 Synthesis of a random structured [VImC4][Br]:[DM-C4][Br]=1:5 copolymer

[0066] At room temperature, [VImC4][Br] monomer (0.3852 g, 1.67 mmol) and [DM-C4][Br] monomer (2.4519 g, 8.33 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-co-[DM-C4]Br 1:5 )(PVIm-DM 1:5 ).

[0067] Example 14 Synthesis of a random structured [VImC4][Br]:[DM-C4][Br]=1:1 copolymer

[0068] At room temperature, [VImC4][Br] monomer (1.1557 g, 5 mmol) and [DM-C4][Br] monomer (1.4712 g, 5 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-co-[DM-C4]Br 1:1 )(PVIm-DM 1:1 ).

[0069] Example 15 Synthesis of a random structured [VImC4][Br]:[DM-C4][Br]=5:1 copolymer

[0070] At room temperature, [VImC4][Br] monomer (1.9261 g, 8.33 mmol) and [DM-C4][Br] monomer (0.4904 g, 1.67 mmol) were dissolved in 12 mL of DMF to obtain a monomer mixed solution; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer mixed solution, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-co-[DM-C4]Br 5:1 )(PVIm-DM 5:1 ).

[0071] Example 16 Synthesis of a block copolymer of [VImC4][Br]:[DM-C4][Br]=1:5

[0072] At room temperature, [VImC4][Br] monomer (0.3852 g, 1.67 mmol) was dissolved in 5 mL of DMF to obtain monomer solution 1, and [DM-C4][Br] monomer (2.4519 g, 8.33 mmol) was dissolved in 7 mL of DMF to obtain monomer solution 2; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer solution 1, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 h. After the reaction, monomer solution 2 was added to the ampoule via a syringe, and the reaction was continued with heating and stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers. The product was then dried under vacuum at 55°C for 24 hours to obtain the copolymer P([VImC4]Br-b-[DM-C4]Br 1:5 ).

[0073] Example 17 Synthesis of a Block-Structured [VImC4][Br]:[DM-C4][Br]=1:1 Copolymer

[0074] At room temperature, [VImC4][Br] monomer (1.1557 g, 5 mmol) was dissolved in 6 mL of DMF to obtain monomer solution 1. [DM-C4][Br] monomer (1.4712 g, 5 mmol) was dissolved in 6 mL of DMF to obtain monomer solution 2. Azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropanoic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF. The resulting mixed solution was added to the above monomer solution 1 and stirred thoroughly to obtain a uniform solution. This solution was added to a 50 mL ampoule and nitrogen was bubbled through a double-row tube to remove dissolved oxygen. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 hours. After the reaction was completed, monomer solution 2 was added to the ampoule using a syringe and the reaction was continued with heating and stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers, and then dried under vacuum at 55 °C for 24 h to obtain the copolymer P([VImC4]Br-b-[DM-C4]Br 1:1 ).

[0075] Example 18 Synthesis of a Block-Structured [VImC4][Br]:[DM-C4][Br]=5:1 Copolymer

[0076] At room temperature, [VImC4][Br] monomer (1.9261 g, 8.33 mmol) was dissolved in 7 mL of DMF to obtain monomer solution 1, and [DM-C4][Br] monomer (0.4904 g, 1.67 mmol) was dissolved in 5 mL of DMF to obtain monomer solution 2; azobisisobutyronitrile (AIBN) (0.0066 g, 0.04 mmol) and 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid (0.0729 g, 0.2 mmol) were dissolved in 3 mL of DMF, and the obtained mixed solution was added to the above monomer solution 1, and the mixture was stirred thoroughly to obtain a uniform solution. The solution was added to a 50 mL ampoule, and nitrogen was bubbled through a double-row tube to remove the dissolved oxygen inside. The ampoule was placed in a 70°C oil bath and heated with stirring for 24 h. After the reaction, monomer solution 2 was added to the ampoule via a syringe, and the reaction was continued with heating and stirring for 24 hours. After the reaction, the product was precipitated with ethyl acetate and washed with ethyl acetate several times to remove unreacted monomers. The product was then dried under vacuum at 55°C for 24 hours to obtain the copolymer P([VImC4]Br-b-[DM-C4]Br 5:1 ).

[0077] (III) Structure and performance characterization of polyionic liquid antibacterial materials

[0078] Depend on Figure 1It can be seen that the copolymer PVIm-DM-C4 synthesized in Example 14 has a higher yield than the monomers [VImC4][Br] and [DM-C4][Br]. 1:1 The NMR peak originally belonging to vinyl hydrogen disappears, which confirms that the vinyl monomer forms a polymer network structure through free radical polymerization. Combined with the retention of other characteristic peaks, it can be inferred that the ionic liquid monomer has successfully participated in the copolymerization reaction and the polymerization reaction is complete.

[0079] Example 19 Static Water Contact Angle Test of Imidazole Polyionic Liquids (PVIm-4, PVIm-8, PVIm-12)

[0080] 30 mg of polymer (PVIm-4 in Example 1, PVIm-8 in Example 2, and PVIm-12 in Example 3) was dissolved in 0.2 mL of methanol to obtain a uniform solution. A clean and dry glass slide was taken and the above solution was evenly coated on the surface of the glass slide using a microsyringe. The slide was then placed in a clean environment to evaporate and dry at room temperature. The deposition-drying cycle was repeated three times at the same position. The dried sample was subjected to a static water contact angle test at room temperature.

[0081] Depend on Figure 2 It can be seen that the alkyl side chain of the imidazole type polyionic liquid is extended from butyl (C4) to dodecyl (C 12 ), the static water contact angle increases from 50.1° to 111.1°, indicating that the hydrophobicity of the polyionic liquid increases with increasing alkyl side chain length. The short-chain PVIm-4 exhibits hydrophilic properties due to limited intermolecular hydrophobic interactions, the presence of polar imidazole rings, and the presence of bromine counterions.

[0082] Example 20 Minimum Inhibitory Concentration (MIC) and Antibacterial Activity Test

[0083] (1) Preparation of sample solution: Weigh 10 mg of solid sample (PVIm-4 in Example 1, PDM-4 in Example 4, PVIm-DM in Example 14) 1:1 ) were added to three sterilized centrifuge tubes, placed in a clean bench and sterilized under ultraviolet light for 30 minutes, and 10 mL of sterilized broth culture medium LB was added to each of the centrifuge tubes to dissolve the solid sample to obtain a sample solution with a concentration of 1.0 mg / mL.

[0084] (2) Minimum inhibitory concentration (MIC) and antibacterial activity test: The prepared 1.0 mg / mL sample solution was diluted in a 96-well plate (2-fold, 1→0.063 mg / mL), and 5% DMSO was added to the solution to improve solubility. 100 μL was added to each well of the plate, and then 100 μL of Staphylococcus aureus suspension (1×106 CFU / mL), and the control group was added with 100 μL of LB and 100 μL of Staphylococcus aureus suspension (1×10 6 CFU / mL), incubate at 37℃ for 4h, take out 10μL bacterial suspension, drop it onto LB agar plate, and spread it evenly. After incubating in a 37℃ incubator for 24h, record the number of surviving bacterial colonies. Each test was repeated three times. sample ) and the colony count of the positive control group (A positive ), the antibacterial efficiency was calculated according to the following formula:

[0085] Antibacterial rate=(A positive -B sample ) / A positive ×100%;

[0086] The minimum concentration of the sample that can completely inhibit the growth of Staphylococcus aureus is the MIC.

[0087] Depend on Figure 3 and Figure 4 It can be seen that the three polyionic liquid materials showed significant differences in antibacterial properties. At the same concentration, when the copolymer PVIm-DM was added 1:1 The bacterial colonies on the LB agar plate of PVIm-4 were the least, and the bacterial survival rate was the lowest, which was much lower than that of the homopolymers PVIm-4 and PDM-4. 1:1 Complete bacteriostasis was achieved at 0.5 mg / mL, and its MIC concentration (0.5 mg / mL) was 55% and 71% lower than that of PVIm-4 (1.1 mg / mL) and PDM-4 (1.7 mg / mL), respectively. Even when the concentration was reduced to 0.063 mg / mL, the bacterial survival rate was less than 50%.

Claims

1. A polyionic liquid-based antibacterial material, characterized in that: The polyionic liquid-based antibacterial material is a polyionic liquid homopolymer or a polyionic liquid copolymer; the polyionic liquid copolymer is a polyionic liquid copolymer with a random structure or a polyionic liquid copolymer with a block structure; The preparation method of the polyionic liquid homopolymer is as follows: dissolving an ionic liquid monomer, a free radical initiator, and a RAFT chain transfer agent in an organic solvent to form a uniform mixed solution, transferring the mixed solution into an ampoule, replacing the atmosphere with nitrogen, and performing a polymerization reaction under heating conditions. After the reaction is completed, the mixture is settled and washed with an organic solvent, and dried to a constant weight to obtain the polyionic liquid homopolymer; The preparation method of the random-structured polyionic liquid copolymer is as follows: under a nitrogen atmosphere, two ionic liquid monomers dissolved in an organic solvent are uniformly mixed to obtain a monomer mixed solution; a RAFT chain transfer agent and a free radical initiator are dissolved in an organic solvent, the obtained mixed solution is added to the monomer mixed solution, a polymerization reaction is carried out under heating conditions, and after the polymerization is completed, the random-structured polyionic liquid copolymer is purified and dried to obtain the random-structured polyionic liquid copolymer; The preparation method of the block-structured polyionic liquid copolymer is as follows: under a nitrogen atmosphere, an ionic liquid monomer is dissolved in an organic solvent to obtain a monomer solution; a RAFT chain transfer agent and a free radical initiator are dissolved in the organic solvent, the obtained mixed solution is added to the monomer solution, a polymerization reaction is carried out under heating conditions, another ionic liquid monomer is added after the polymerization reaction is completed, and the polymerization reaction is continued. After the polymerization is completed, the copolymer is purified and dried to obtain the block-structured polyionic liquid copolymer.

2. A polyionic liquid-based antibacterial material according to claim 1, characterized in that: The chemical structural formula of the ionic liquid monomer is any one of (I), (II), (III) and (IV): Among them, X1 - 、X2 - 、X3 - and X4 - All Cl - Br - , I - Any one of; R1, R2, R3 and R4 are all alkyl C n H 2n+1 , n ranges from 1 to 16.

3. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: In the method for preparing the polyionic liquid homopolymer, the total concentration of the ionic liquid monomer in the mixed solution is 0.5 to 1.0 mol / L.

4. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: In the preparation method of the random-structured polyionic liquid copolymer and the block-structured polyionic liquid copolymer, the molar ratio of the two ionic liquid monomers is 1:100 to 100:

1.

5. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: The free radical initiator is any one of azobisisobutyronitrile, azobiscyanovaleric acid, ammonium persulfate, and potassium persulfate.

6. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: The RAFT chain transfer agent is any one of 2-[dodecylthio(thiocarbonyl)thio]-2-methylpropionic acid, 4-cyano-4-[[(dodecylthio)thioketonemethyl]thio]pentanoic acid, and S,S-dibenzyl trithiocarbonate.

7. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: The molar ratio of the RAFT chain transfer agent to the total amount of the ionic liquid monomer is 1:200 to 1:

20.

8. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: The organic solvent used to dissolve the ionic liquid monomer, free radical initiator or RAFT chain transfer agent is an organic solvent with a boiling point of 80 to 160° C.; the organic solvent used for sedimentation and washing is an organic solvent with a boiling point of 40 to 80° C.; and the drying temperature is 40 to 80° C.

9. The polyionic liquid-based antibacterial material according to claim 1, characterized in that: The heating temperature of the polymerization reaction is 50-80° C., and the reaction time is 24-48 hours.

10. Use of the polyionic liquid-based antibacterial material according to any one of claims 1 to 9 in the antibacterial field.

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