Preparation method and application of ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material

Abstract

The application discloses a preparation method of ZnO QDs / Ga@ amphiphilic parenchyma cellulose composite material, which adopts a N,N-dimethylacetamide-lithium chloride system to dissolve corn straw parenchyma cellulose, and pyridinium amphiphilic monomers are grafted on the cellulose chain through an ATRP method to obtain amphiphilic cellulose; metal gallium is added into N,N-dimethylacetamide containing zinc acetate and is ultrasonically dispersed, then the amphiphilic cellulose is added into the dispersion liquid and is uniformly mixed, the mixture is added dropwise into a sodium n-butyl alcohol solution to perform hydrothermal reaction, and after the reaction is completed, the product is washed, freeze-dried, and the ZnO QDs / Ga@ amphiphilic parenchyma cellulose composite material is obtained; the composite material is applied in a Candida albicans bacteriostatic experiment, and exhibits excellent antibacterial effect under the condition of not depending on illumination.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of agricultural solid waste corn stalk parenchyma cellulose, after imidazolium monomer is endowed and is loaded ZnO quantum dot (QDs) / Ga composite material preparation process, the composite material has strong, durable antibacterial capacity, belongs to natural polymer modified material technical field. BACKGROUND

[0002] Every year, hundreds of millions of people worldwide are threatened by fungal infectious diseases. The long-term use of traditional antifungal drugs (such as azoles and polyenes) has led to the frequent occurrence of drug-resistant strains, forcing people to develop new types of antibacterial agents. As natural antibacterial molecules, antimicrobial peptides (AMPs) have low biological toxicity and have received extensive attention due to their unique bactericidal mechanism. Unlike traditional synthetic drugs, AMPs achieve bactericidal effects through their unique amphiphilic structure: the cationic region targets the negatively charged groups on the surface of microbial membranes (such as fungal cell membranes ergosterol and bacterial lipopolysaccharides) through electrostatic interactions, and the hydrophobic region inserts into the phospholipid bilayer to form a transmembrane pore, disrupting membrane integrity and causing cell contents to leak. Due to this mechanism, which does not rely on specific enzyme targets, drug resistance can be effectively delayed. However, the therapeutic application of natural AMPs is limited by their stability and production costs, so the development of antimicrobial peptide mimics (AMPM) that mimic the functional characteristics of natural AMPs has become a research hotspot.

[0003] Imidazole derivatives (such as metronidazole and ketoconazole) have been proven to have broad-spectrum antibacterial activity, and their active imidazole aromatic ring structure helps to develop antimicrobial peptide synthesis systems and compensate for the poor stability of antimicrobial peptides. However, current research on the amphiphilic structure of imidazolium antimicrobial peptide mimics still has significant shortcomings.

[0004] Zinc oxide is widely used in the biomedical field due to its non-toxic properties, good biological safety, and biocompatibility. The U.S. Food and Drug Administration (FDA) has listed it as a Generally Recognized as Safe (GRAS) substance and approved it as an antibacterial agent for food storage and medical fields. Zinc oxide quantum dots (ZnO QDs) exhibit stronger microbial inhibition than zinc oxide nanoparticles (ZnO NPs) due to their unique small size advantage.

[0005] With the continuous development of human society, the traditional chemical industry is facing the double constraints of fossil energy shortage and environmental problems, and the reuse of waste biomass resources has become a research hotspot. Biomass materials have the advantages of abundant reserves, green and safe, and sustainable regeneration, and have broad application prospects as carriers of quantum dot materials. Corn straw, as one of the agricultural wastes with the highest production in China, is often incinerated on site, which not only causes serious environmental pollution, but also wastes this rich biomass resource. Corn straw is mainly composed of straw skin and straw core, among which the straw skin has been widely used in the pulp and paper industry, while the utilization rate of the straw core is low. Corn straw core is mainly composed of parenchymal cells and vessel cells, among which the parenchymal cells have thin cell walls and strong extensibility and plasticity. From the perspective of chemical composition, the parenchymal cells contain rich carbohydrates (mainly cellulose), and these carbohydrate macromolecular chains contain rich hydroxyl groups, providing a good chemical basis. Therefore, through this resource advantage, the development of green and environmentally friendly and efficient antibacterial materials can be realized. SUMMARY

[0006] The application provides a preparation method of ZnO QDs / Ga@ amphiphilic parenchymal cellulose composite material. The method uses corn straw core as raw material, which is rich in resources but lacks a complete utilization system. After being crushed, delignified and hemicellulose-removed, a homogeneous solution is prepared by using N, N-dimethylacetamide (DMAc) / LiCl system dissolution. The imidazolium amphiphilic monomer is homogeneously grafted on the cellulose by atom transfer radical polymerization (ATRP) to obtain amphiphilic cellulose polymer. At the same time, metal Ga is added to the zinc salt solution, ultrasonic dispersion is carried out, and then the amphiphilic cellulose polymer is mixed. Alkaline solution regeneration and drying obtain corn straw core parenchymal cell amphiphilic cellulose loaded ZnO QDs / Ga composite material, which further provides a new theoretical basis and technical foundation for the high-value utilization of agricultural straw.

[0007] The specific steps of the method are as follows

[0008] (1) The dried corn stalks are peeled, powdered, and sieved to obtain a 50-150 mesh size of the stalk powder; 400-800 mL of deionized water, 10-15 g of lithium chlorate, and 5-10 mL of hypochlorous acid are added to 10-30 g of the stalk powder, which is mixed and placed in a 75-85℃ constant temperature water bath for 0.5-1.5 h; 5-10 g of lithium chlorate and 3-7 mL of hypochlorous acid are added again and reacted for 0.5-1.5 h, and this operation is repeated 3-7 times; after the reaction is completed, the product is washed with deionized water until the pH is neutral, and then freeze-dried; the dried product is diluted with water, 8-12% of potassium hydroxide based on the mass of the dried product is added, and the mixture is mixed and placed in a 20-30℃ constant temperature water bath for 10-12 h; after the reaction is completed, the product is placed in a 1000-3000 mesh nylon mesh bag and washed with deionized water until the pH is neutral; and the dried product is obtained, which is corn stalk pith cellulose with a degree of polymerization of 700-1200;

[0009] (2) 1-alkyl imidazole and 3-chloropropene are weighed and added to acetonitrile, and reacted at 50-80℃ for 36-60 h, wherein the molar ratio of 1-alkyl imidazole to 3-chloropropene is 1:1.2-1:1.6; after the reaction is completed, the excess solvent is removed by rotary evaporation, the product is dissolved in deionized water and transferred to a separatory funnel, petroleum ether is added for washing, the aqueous phase is collected, and freeze-drying is performed to obtain an imidazolium amphiphilic monomer;

[0010]

[0011] (3) The absolute dry corn stalk pith cellulose is weighed and added to N, N-dimethylacetamide, and placed in a 80-140℃ constant temperature water bath for 1-3 h; then lithium chloride is added, and reacted at 70-130℃ for 1-3 h; then sealed and cooled; and reacted at 2-6℃ for 3-24 h to obtain a corn stalk pith cellulose solution; wherein the mass-volume ratio g:mL of the absolute dry corn stalk pith cellulose to N, N-dimethylacetamide is 4-10%, and the mass-volume ratio g:mL of lithium chloride in N, N-dimethylacetamide is 6-10%;

[0012] 2-bromopropionyl bromide (BiB) and triethylamine (TEA) are added to the corn stalk pith cellulose solution, and stirred in a 20-40℃ constant temperature water bath for 3-36 h; the reaction product is added to deionized water for regeneration, and washed repeatedly with deionized water until the solution is neutral; and then freeze-dried to obtain a CC-BiB macromolecular initiator; wherein the molar mass ratio mmol:g of 4-bromopropionyl bromide to corn stalk pith cellulose is 2-10:1, and the molar mass ratio mmol:g of triethylamine to corn stalk pith cellulose is 2.3-11.5:1;

[0013] (4) the dried CC-BiB macroinitiator is added into N, N-dimethylacetamide, and is reacted at 80-140 DEG C for 1-3 hours, then lithium chloride is added, and is reacted at 70-130 DEG C for 1-3 hours, then is sealed and cooled, and is reacted at 2-6 DEG C for 3-24 hours to obtain an initiator solution; nitrogen is continuously introduced into the initiator solution, then imidazolium amphiphilic monomer, tris (2-dimethylaminoethyl) amine and FeBr2 are added, and are reacted at 45-75 DEG C for 3-15 hours to obtain the amphiphilic cellulose polymer (CC-g-Pim);

[0014] The mass-volume ratio g:mL of the CC-BiB macroinitiator and N, N-dimethylacetamide is 4-10%, and the mass-volume ratio g:mL of lithium chloride in N, N-dimethylacetamide is 6-10%;

[0015] The molar ratio of the CC-BiB macroinitiator and imidazolium amphiphilic monomer is 1:25-1:100, the molar ratio of the CC-BiB macroinitiator and tris (2-dimethylaminoethyl) amine is 1:0.225-1:2.7, and the molar ratio of the CC-BiB macroinitiator and FeBr2 is 1:0.25-1:1;

[0016] (5) gallium is added into N, N-dimethylacetamide with a concentration of 0.02-0.06 mmol / mL zinc acetate and is ultrasonically dispersed, then the amphiphilic cellulose polymer is added, and after mixing, the mixture is added dropwise into a sodium n-butylate aqueous solution, and is hydrothermally reacted at 120-240 DEG C for 3-24 hours; after the reaction is completed, the product is washed and freeze-dried to obtain a ZnO QDs / Ga@amphiphilic thin-walled cellulose composite material; wherein the molar ratio of Ga and Zn 2+ is 0.5:1-1.2:1, the molar ratio of sodium n-butylate and Zn 2+ is 1.6:1-3.6:1, and the mass ratio of the amphiphilic cellulose polymer and Ga is 10:1-14:1.

[0017] The beneficial effects of the present application are: corn stalks, an agricultural waste, are used as a natural polymer source, and are subjected to screening, air drying, peeling, delignification, hemicellulose removal, dissolution and other operations to obtain a thin-walled cellulosic solution. The hydrogen bonds between the treated cellulose molecules are destroyed, the structure is disintegrated, and active hydroxyl functional groups are exposed, which significantly improves the reaction accessibility of the cellulose, facilitates the introduction of imidazolium monomers and zinc oxide quantum dots, and after modification, the cellulose-based composite exhibits good anchoring and microbial enrichment effects, thereby realizing targeted antibacterial function. Meanwhile, DMAc containing zinc ions can rapidly ultrasonically disperse liquid gallium to obtain Zn 2+The gallium-based nanodroplets (Ga NDs) provide in-situ growth reaction sites for synthesizing zinc oxide quantum dots. By mixing the above solution with a modified cellulose dissolving solution, and regenerating in a sodium butyl alcohol aqueous solution, a composite material with high antibacterial effect is finally obtained. The composite material is applied in the antibacterial experiment of Candida albicans, and shows excellent antibacterial effect under the condition of not depending on light, which provides a new idea for realizing high value-added utilization of corn straw and inhibition of harmful microorganisms. DETAILED DESCRIPTION

[0018] The application will be further described in detail below in combination with examples, but the protection scope of the application is not limited to the content described, and the methods used in the examples are all conventional methods unless otherwise specified, and the reagents used are all conventional reagents unless otherwise specified. Example 1

[0019] (1) The air-dried corn straw is peeled, powdered and sieved to obtain straw powder with a particle size of 50-100 mesh;

[0020] (2) 400 mL of deionized water, 10 g of lithium chlorate and 5 mL of hypochlorous acid are added to 10 g of the straw powder, and the mixture is uniformly mixed and placed in a 75°C constant temperature water bath for 1.5 h. Then 5 g of lithium chlorate and 3 mL of hypochlorous acid are added again, and the reaction is carried out for 0.5 h and this operation is repeated for 3 times. After the reaction is completed, the product is soaked and washed with deionized water until the pH is neutral, and then freeze-dried. The dried product is diluted with water, 8% of potassium hydroxide based on the mass of the dried product is added and mixed, and then placed in a 20°C constant temperature water bath for 12 h. After the reaction is completed, the product is washed and soaked in deionized water in a 1000-mesh nylon mesh bag until the pH of the material is neutral, and then dried to obtain corn straw parenchyma cellulose;

[0021] (3) 4.41 g of 1-propylimidazole and 3.67 g of 3-chloropropene are added to 60 mL of acetonitrile, and the reaction is carried out at 50°C for 60 h. After the reaction is completed, the excess solvent is removed by a rotary evaporator, the product is dissolved in 30 mL of water and transferred to a separatory funnel, petroleum ether (40 mL x 3) is added for washing, the combined water phase is collected, and freeze-dried to obtain 3-allyl-1-propylimidazolium chloride;

[0022] (4) 1 g of absolute dry corn straw pith cellulose was added into N, N-dimethylacetamide and reacted at 80 °C for 3 h, wherein the mass-volume ratio g: mL of the absolute dry corn straw pith cellulose and N, N-dimethylacetamide was 4%, after the reaction, lithium chloride was added, the mass-volume ratio g: mL of lithium chloride and N, N-dimethylacetamide was 6%, and the mixture was reacted at 70 °C for 3 h, after the reaction, the mixture was sealed and cooled, and reacted at 2 °C for 3 h to obtain a corn straw pith cellulose solution; BiB (2 mmol of BiB was added per gram of cellulose) and TEA (2.3 mmol of TEA was added per gram of cellulose) were added into the cellulose solution, and the mixture was stirred in a 20 °C constant temperature water bath for 15 h, then the product was added into deionized water for regeneration, and washed repeatedly with deionized water until the solution was neutral, and then freeze-dried to obtain a CC-BiB macromolecular initiator;

[0023] (5) The dry CC-BiB macromolecular initiator was added into N, N-dimethylacetamide (4%), and reacted at 80 °C for 3 h, then lithium chloride (6%) was added, and the mixture was reacted at 70 °C for 3 h, then sealed and cooled, and reacted at 2 °C for 3 h to obtain an initiator solution; nitrogen was continuously introduced into the initiator solution, then 3-allyl-1-propylimidazolium chloride (the molar ratio of CC-BiB and imidazolium was 1:25), tris(2-dimethylaminoethyl)amine (the molar ratio of CC-BiB and Me6TREN was 1:0.225), and FeBr2 (the molar ratio of CC-BiB and FeBr2 was 1:0.25) were added, and the mixture was reacted at 45 °C for 15 h to obtain an amphiphilic cellulose polymer;

[0024] (6) 0.1 g of metallic gallium was added into 5 mL of N, N-dimethylacetamide containing 0.02 mmol / mL of zinc acetate, and ultrasonically dispersed, then 1 g of the amphiphilic cellulose polymer was added and uniformly dispersed, and the mixture was added dropwise into 10 mL of 0.016 mmol / mL of sodium n-butylate aqueous solution, and hydrothermally reacted at 120 °C for 24 h, after the reaction, the product was washed, freeze-dried, and ZnO QDs / Ga@amphiphilic pith cellulose supported ZnO / Ga composite material was obtained; wherein the molar ratio of Ga and Zn 2+ was 0.5:1, the molar ratio of sodium n-butylate and Zn 2+ was 1.6:1, and the mass ratio of the amphiphilic cellulose polymer and Ga was 10:1;

[0025] Comparative Example 1: the method was the same as above, except that the CC-g-Pim polymer was added into N, N-dimethylacetamide containing 0.02 mmol / mL of zinc acetate and uniformly stirred, then added dropwise into the sodium n-butylate aqueous solution, and no Ga was added, to obtain ZnO FNS@amphiphilic pith cellulose composite material;

[0026] The antibacterial performance test method of the composite material: plate coating method refers to the standard GB 21551 2-2010, the minimum inhibitory concentration of the complex on Candida albicans is 10 mg / mL, and the minimum inhibitory concentration of the comparative example ZnO FNS@ amphiphilic thin-walled cellulose composite on Candida albicans is 20 mg / mL, respectively. Candida albicans Example 2

[0027] (1) The dried corn straw is peeled, powdered and sieved to obtain straw core powder with a particle size of 100-150 mesh;

[0028] (2) 600 mL of deionized water, 12.5 g of lithium chlorate and 7.5 mL of hypochlorous acid are added to 15 g of straw core powder, and the mixture is uniformly mixed and placed in a 80°C constant temperature water bath for 1 h. Then 7.5 g of lithium chlorate and 5 mL of hypochlorous acid are added again and reacted for 1 h, and this operation is repeated 5 times. After the reaction is completed, the product is soaked and washed with deionized water until the pH is neutral. After freeze-drying, the dried product is diluted with water, 10% of the mass of the dried product is added to the mixture, and the mixture is uniformly mixed and placed in a 25°C constant temperature water bath for 11 h. After the reaction is completed, the product is placed in a 2000 mesh nylon mesh bag and washed with deionized water until the pH of the material is neutral. After drying, corn straw core thin-walled cellulosic is obtained;

[0029] (3) 7.27 g of 1-propylimidazole and 6.42 g of 3-chloropropene are added to 90 mL of acetonitrile, and the mixture is reacted at 65°C for 48 h. The molar ratio of 1-propylimidazole to 3-chloropropene is 1:1.4. After the reaction is completed, the excess solvent is removed by rotary evaporation. The product is dissolved in 30 mL of water and transferred to a separatory funnel. Petroleum ether (40 mL x 3) is added to wash, and the combined aqueous phase is collected and freeze-dried to obtain 3-allyl-1-propylimidazolium chloride;

[0030] (4) 2 g of absolute dry corn straw core thin-walled cellulosic is added to N, N-dimethylacetamide, and the mixture is reacted at 110°C for 2 h. The mass-volume ratio of absolute dry corn straw core thin-walled cellulosic to N, N-dimethylacetamide is 8%. After the reaction is completed, lithium chloride is added. The mass-volume ratio of lithium chloride in N, N-dimethylacetamide is 8%. The mixture is reacted at 100°C for 2 h. After the reaction is completed, it is sealed and cooled at 4°C for 12 h to obtain a corn straw core thin-walled cellulosic solution. BiB (6 mmol of BiB is added per gram of cellulose) and TEA (6.9 mmol of TEA is added per gram of cellulose) are added to the cellulose solution, and the mixture is stirred in a 30°C constant temperature water bath for 20 h. The product is regenerated by adding deionized water and repeatedly washing with deionized water until the solution is neutral. Then it is freeze-dried to obtain a CC-BiB macromolecular initiator; ​

[0031] (5) The CC-BiB macroinitiator was dissolved in the DMAC / LiCl system (the method is the same as step (4)) to prepare an initiator solution, nitrogen was continuously introduced into the initiator solution, and then 3-allyl-1-propylimidazolium chloride (the molar concentration ratio of CC-BiB to imidazolium was 1:50), tris(2-dimethylaminoethyl)amine (the molar concentration ratio of CC-BiB to Me6TREN was 1:1.5), and FeBr2(the molar concentration ratio of CC-BiB to FeBr2was 1:0.5) were added, and after reaction in a 60°C constant-temperature oil bath for 9 h, a CC-g-Pim polymer was obtained;

[0032] (6) 0.4 g of metallic gallium was added to 0.04 mmol / mL zinc acetate in N,N-dimethylacetamide 10 mL and ultrasonically dispersed, then 4.8 g of the CC-g-Pim polymer was added and uniformly dispersed, and the mixture was added dropwise to 0.056 mmol / mL sodium n-butylate aqueous solution 20 mL, and hydrothermal reaction was performed at 150°C for 6 h, after the reaction was completed, the product was washed and freeze-dried to obtain a ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material, wherein the molar ratio of Ga to Zn 2+ was 0.8:1, the molar ratio of sodium n-butylate to Zn 2+ was 2.8:1, and the mass ratio of the amphiphilic cellulose polymer to Ga was 12:1.

[0033] Comparative Example 2: The method was the same as above, except that the CC-g-Pim polymer was added to 0.04 mmol / mL zinc acetate in N,N-dimethylacetamide 10 mL and stirred uniformly, then added dropwise to the sodium n-butylate aqueous solution without adding Ga, to prepare a ZnO FNS@ amphiphilic thin-walled cellulose composite material;

[0034] The antibacterial performance test method of the composite material was a plate coating method according to the standard GB 21551 2-2010, the minimum inhibitory concentration of the ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material of the application to Candida albicans was 5 mg / mL, and the minimum inhibitory concentration of the comparative example ZnO FNS@ amphiphilic thin-walled cellulose composite material to Candida albicans was 14 mg / mL. Example 3

[0035] (1) The dried corn straw was peeled, powdered, and sieved to obtain a straw powder with a particle size of 80-120 mesh;

[0036] (2) In 30 g of straw powder, 800 mL of deionized water, 15 g of lithium chlorate, 10 mL of hypochlorous acid were added, mixed and placed in a 85℃ constant temperature water bath for 0.5 h, then 10 g of lithium chlorate and 7 mL of hypochlorous acid were added again and reacted for 1.5 h and this operation was repeated 6 times, after the reaction was completed, the product was soaked and washed with deionized water until the pH was neutral, then freeze-dried, the dry material was diluted with water, 12% of the dry material was added Potassium hydroxide was mixed and placed in a 30℃ constant temperature water bath for 10 h, after the reaction was completed, the product was placed in a 3000 mesh nylon mesh bag and washed with deionized water until the material pH was neutral, dried to obtain corn straw parenchyma cellulose;

[0037] (3) 8.81 g of 1-butyl imidazole and 9.79 g of 3-chloropropene were added to 120 mL of acetonitrile, reacted at 80℃ for 36 h, the molar ratio of 1-butyl imidazole to 3-chloropropene was 1:1.6, after the reaction was completed, the excess solvent was removed by rotary evaporation, the product was dissolved in 30 mL of water and transferred to a separatory funnel, washed with petroleum ether (40 mL x 3), the combined aqueous phase was collected, and freeze-dried to obtain 3-allyl-1-butyl imidazolium chloride;

[0038] (4) 3 g of absolutely dry corn straw parenchyma cellulose was added to N, N-dimethylacetamide solution, the mass-volume ratio of absolutely dry corn straw parenchyma cellulose to N, N-dimethylacetamide was 10%, and it was placed in a 140℃ constant temperature water bath for 1 h, after the reaction was completed, lithium chloride was added, the mass-volume ratio of lithium chloride in N, N-dimethylacetamide was 10%, and it was reacted at 130℃ for 1 h, after the reaction was completed, it was sealed and cooled, and reacted at 6℃ for 10 h to obtain a parenchyma cellulose solution; BiB (10 mmol of BiB was added per gram of cellulose) and TEA (11.5 mmol of TEA was added per gram of cellulose) were added to the cellulose solution, stirred in a 40℃ constant temperature water bath for 36 h, then the product was regenerated by adding deionized water and repeatedly washing with deionized water until the solution was neutral, then freeze-dried to obtain a CC-BiB macromolecular initiator;

[0039] (5) The CC-BiB macromolecular initiator was dissolved in a DMAC / LiCl system to obtain an initiator solution (the method is the same as step (4)), nitrogen was continuously introduced into the initiator solution, then 3-allyl-1-butyl imidazolium chloride (the molar concentration ratio of CC-BiB to imidazolium was 1:100), tris(2-dimethylaminoethyl)amine (the molar concentration ratio of CC-BiB to Me6TREN was 1:2.7) and FeBr2 (the molar concentration ratio of CC-BiB to FeBr2 was 1:1) were added, and a CC-g-Pim polymer was obtained after reacting in a 75℃ constant temperature oil bath for 3 h.

[0040] (6) 0.7 g of metallic gallium was added to 0.06 mmol / mL zinc acetate in N,N-dimethylacetamide 20 mL and ultrasonically dispersed, then 9.8 g of CC-g-Pim polymer was added and mixed, and the mixture was added dropwise to 0.108 mmol / L sodium n-butyl alcohol aqueous solution 40 mL, and hydrothermal reaction was carried out at 240°C for 3 h. After the reaction, the product was washed, freeze-dried, and ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material was obtained, wherein the molar ratio of Ga to Zn 2+ was 1.2:1, the molar ratio of sodium n-butyl alcohol to Zn 2+ was 3.6:1, and the mass ratio of amphiphilic cellulose polymer to Ga was 14:1.

[0041] Comparative Example 3: The method was the same as above, except that the CC-g-Pim polymer was added to 0.06 mmol / mL zinc acetate in N,N-dimethylacetamide and stirred until uniform, then added dropwise to the sodium n-butyl alcohol aqueous solution, without adding Ga, to prepare a ZnO FNS@ amphiphilic thin-walled cellulose composite material;

[0042] The antibacterial performance test method of the composite material was a plate coating method according to standard GB 21551 2-2010. The minimum inhibitory concentration of the composite material on Candida albicans was 0.6 mg / mL, and the minimum inhibitory concentration of the ZnO FNS@ amphiphilic thin-walled cellulose composite material of the comparative example on Candida albicans was 12 mg / mL.

Claims

1. A method for preparing a ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material, characterized in that, The steps are as follows: (1) corn straw pith cellulose is dissolved in N, N-dimethylacetamide-lithium chloride system; 2-bromopropionyl bromide and triethylamine are added to the corn straw pith cellulose solution, and the reaction product is added to deionized water for regeneration and washed to neutral, and freeze-dried to obtain CC-BiB macromolecular initiator; (2) 1-alkyl imidazole is mixed with 3-chloropropene in acetonitrile, and after reaction at 50~80℃ for 36~60h, the solvent is removed by rotary evaporation, deionized water is added to dissolve the product, petroleum ether is used for washing, and the water phase is collected and freeze-dried to obtain imidazolium amphiphilic monomer; (3) the CC-BiB macromolecular initiator is dissolved in N, N-dimethylacetamide-lithium chloride system to obtain an initiator solution, nitrogen is continuously introduced into the initiator solution, and then imidazolium amphiphilic monomer, tris(2-dimethylaminoethyl)amine and FeBr2 are added, and the reaction is carried out at 45~75℃ for 3~15h to obtain amphiphilic cellulose polymer; (4) gallium is added to N, N-dimethylacetamide containing zinc acetate and ultrasonically dispersed, then the amphiphilic cellulose polymer is added to the dispersion and uniformly mixed, and the mixture is added dropwise into a sodium n-butyl alcohol aqueous solution, and the reaction is carried out at 120~240℃, after the reaction is completed, the reaction product is washed and freeze-dried to obtain ZnO QDs / Ga@amphiphilic pith cellulose composite material.

2. The method for preparing ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material according to claim 1, characterized in that: The corn straw pith cellulose is obtained by peeling, powdering and sieving the air-dried corn straw, adding 400~800mL deionized water, 10g~15g lithium chlorate and 5~10mL hypochlorous acid to 10~30g of the corn straw pith powder, uniformly mixing, and then treating at 75~85℃ for 0.5~1.5h, and then adding 5~10g of lithium chlorate and 3~7mL of hypochlorous acid and reacting for 0.5~1.5h and repeating the operation for 3~7 times, and then washing the reaction product with deionized water until the pH is neutral, and freeze-drying, diluting with water, adding 8~12% of potassium hydroxide based on the dry weight, uniformly mixing, and then treating at 20~30℃ for 10~12h, and then washing with deionized water in a 1000~3000 mesh nylon mesh bag until the pH is neutral, and drying to obtain the corn straw pith cellulose.

3. The method for preparing ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material according to claim 1, characterized in that: The corn straw pith cellulose is dissolved in N, N-dimethylacetamide-lithium chloride system by weighing the absolute dry corn straw pith cellulose and adding it to N, N-dimethylacetamide, treating at 80~140℃ for 1~3h, adding lithium chloride, treating at 70~130℃ for 1~3h, sealing and cooling, and then treating at 2~6℃ for 3~24h to obtain the corn straw pith cellulose solution; wherein the mass-volume ratio g:mL of the absolute dry corn straw pith cellulose to N, N-dimethylacetamide is 4~10%, and the mass-volume ratio g:mL of lithium chloride in N, N-dimethylacetamide is 6~10%.

4. The method for preparing ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material according to claim 1, characterized in that: The molar mass ratio of 2-bromopropionyl bromide to corn straw pith cell cellulose is 2-10:1, and the molar mass ratio of triethylamine to corn straw pith cell cellulose is 2.3-11.5:

1.

5. The method for preparing ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material according to claim 1, characterized in that: The molar ratio of 1-alkyl imidazole to 3-chloropropene is 1:1.2-1:1.

6.

6. The method for preparing ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material according to claim 1, characterized in that: The molar ratio of CC-BiB macroinitiator to imidazolium amphiphilic monomer is 1:25-1:100, the molar ratio of CC-BiB macroinitiator to tri(2-dimethylaminoethyl)amine is 1:0.225-1:2.7, and the molar ratio of CC-BiB macroinitiator to FeBr2 is 1:0.25-1:

1.

7. The method for preparing ZnO QDs / Ga@ amphiphilic thin-walled cellulose composite material according to claim 1, characterized in that: The concentration of zinc acetate in N,N-dimethylacetamide containing zinc acetate is 0.02~0.06 mmol / mL, and Ga and Zn 2+ The molar ratio is 0.5:1 to 1.2:1, with sodium n-butoxide and Zn 2+ The molar ratio is 1.6:1 to 3.6:1, and the mass ratio of amphiphilic cellulose polymer to Ga is 10:1 to 14:

1.

8. The application of the ZnO QDs / Ga@ amphiphilic pith cellulose composite material prepared by the preparation method of the ZnO QDs / Ga@ amphiphilic pith cellulose composite material in claim 1-7 in the preparation of antibacterial agents.

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