石墨烯负载银基纳米颗粒复合材料的制备及性能研究
发布时间：2018-10-10 09:52
【摘要】：纳米银(Silver nanoparticles,AgNPs)由于其优异的抗菌性能、抗菌的广谱性和高安全性,被广泛应用于人们日常生活中,如眼药水、食品保藏、化妆品、消毒剂和水处理材料等,对保护人类的健康发挥着巨大的作用。然而,AgNPs由于活性高,稳定性较差,因此容易造成Ag快速流失,这不仅会降低AgNPs的抗菌性能,增加成本,还可能会产生重金属污染。针对这些难题,本文利用氧化石墨烯(graphene oxide,GO)大的比表面积,以GO为载体,均匀分散Ag基纳米粒子,提高其抗菌性能,引入铁元素(Fe),制备具有磁性的复合材料,便于抗菌材料的回收使用,通过构筑还原氧化石墨烯(reduced graphene oxide,rGO)负载AgFe或Ag/Fe_3O_4纳米粒子复合材料,获得可分离的新型抗菌材料。详细研究制备工艺参数对复合材料的组成、组分以及微观形貌和结构的影响规律,重点研究复合材料的微观结构与抗菌、杀菌以及生物相容性之间的联系,获得高抗菌性能和良好生物相容性的可分离的新型抗菌材料以及其可控合成的工艺参数。主要研究内容如下:1.采用原位生长法制备AgFe/r GO复合材料。以GO为载体,硝酸银(AgNO_3)和九水硝酸铁(Fe(NO_3)_3·9H_2O)为金属前驱体,硼氢化钠(NaBH_4)为还原剂,通过一步反应制备AgFe/rGO复合材料,以格兰氏阴性菌大肠杆菌(Escherichia coli,E.coli)和格兰氏阳性菌金黄色葡萄球菌(Staphylococcus aureus,S.aureus)为实验菌株,研究复合材料的抗菌性能。结果表明,反应溶液的pH值和金属前驱体投料比是调控复合材料微观结构的重要因素,当pH为9.5,Ag~+与Fe~(3+)摩尔比为1:1时制备的复合材料中纳米粒子具有AgFe合金结构,粒子形貌均一,尺寸小(~5 nm),在rGO片层中分散度高。该工艺条件制备的复合材料具有优异的抗菌性能,其对E.coli和S.aureus的最低抑菌浓度(Minimum inhibitory concentration,MIC)分别为80 mg/L和120 mg/L,最低杀菌浓度(Minimum bactericidal concentration,MBC)分别为50 mg/L和100 mg/L。同时,该复合材料在50 mg/L浓度以下时,具有良好的生物相容性。2.采用两步法制备Ag/Fe_3O_4/rGO新型抗菌材料。以GO为载体,AgNO_3和四水氯化亚铁(FeCl_2·4H_2O)为金属前驱体,NaBH_4为还原剂,先制备Fe_3O_4/rGO,再进一步引入Ag,最终获得Ag/Fe_3O_4/rGO复合材料。结果表明,金属前驱体投料比是调控复合材料微观结构的重要因素,当Ag~+与Fe2+摩尔比为1:2时制备的复合材料中纳米颗粒均匀负载,Fe_3O_4纳米颗粒平均粒径为10 nm,AgNPs呈类球形,颗粒尺寸集中分布在20 nm以内。该工艺条件制备的复合材料集磁性能与抗菌性能于一体,其饱和磁化率为24.7 Am~2/kg,可以被磁铁吸引,对E.coli和S.aureus的MIC值分别为50 mg/L和80 mg/L,MBC值分别为30 mg/L和50 mg/L。同时,该复合材料具有良好的生物安全性。3.采用化学还原-凝胶反应法制备AgFe/三维石墨烯(AgFe/graphene cellular monolith,AgFe/GCM)新型抗菌材料。将AgNO_3、Fe(NO_3)_3·9H_2O溶液与GO悬浮液混合,经NaBH_4和抗坏血酸处理,在90℃环境下反应4 h使反应物组装成凝胶材料,冷冻干燥即得AgFe/GCM复合材料。结果表明,反应前驱体中Ag~+与Fe~(3+)摩尔比对复合材料形貌结构和颗粒负载具有重要影响,当比例为1:1时制备的复合材料孔道结构明显,AgFe纳米颗粒均匀负载。对E.coli和S.aureus的MIC值分别为50 mg/L和100 mg/L,MBC值分别为30 mg/L和50 mg/L,用气凝胶对细菌进行5次过滤,其杀灭比例约为70%,抗菌性能结果表明,该复合材料在水过滤杀菌方面具有潜在的应用价值。此外,Fe的加入,降低了Ag~+释放速度,使复合材料能够长时间的释放Ag~+来杀菌。复合材料浓度为50 mg/L时,细胞存活率是85%,具有优良的生物安全性。
[Abstract]:Silver and AgNPs have been widely used in people's daily life due to their excellent antibacterial performance, antimicrobial resistance and high safety, such as food preservation, food preservation, cosmetics, disinfectants and water treatment materials, which play a great role in protecting human health. However, AgNPs can easily lead to rapid Ag loss due to high activity and poor stability, which not only reduces the antibacterial performance of AgNPs, increases the cost, but also can produce heavy metal pollution. In order to solve these problems, using the specific surface area of graphene oxide (GO), GO as a carrier, uniformly dispersing Ag-based nanoparticles, improving its antibacterial property, introducing Fe element (Fe), preparing composite material with magnetic properties, and facilitating the recovery and use of the material. By constructing the reduced graphene oxide (rGO) loaded AgFe or Ag/ Fe _ 3O _ 4 nano-particle composite material, a new kind of new material was obtained. The effects of preparation process parameters on composition, composition, microstructure and structure of composite materials are studied in detail, and the relationship between microstructure and antibacterial, sterilization and biocompatibility of composite materials is studied. high antibacterial performance and good biocompatibility can be obtained, and the controllable synthetic process parameters are obtained. The main contents are as follows: 1. AgFe/ r GO composite was prepared by in situ growth method. The AgFe/ rGO composite was prepared by one-step reaction with GO as carrier, silver nitrate (AgNO _ 3) and nine-water ferric nitrate (Fe (NO _ 3) _ 3 路 9H _ 2O) as the metal precursor, and the AgFe/ rGO composite was prepared by one-step reaction. E. coli and Staphylococcus aureus (S. auratus) were the experimental strains, and the antibacterial properties of the composites were studied. The results show that the pH value of the reaction solution and the feeding ratio of the metal precursor are important factors for regulating the microstructure of the composite material. When the pH is 9. 5, the molar ratio of Ag ~ + to Fe ~ (3 +) is 1: 1, the nano-particles have AgFe alloy structure, and the morphology of the particles is uniform. The size was small (~ 5 nm), and the dispersity was high in the rGO layer. The minimum inhibitory concentration (MIC) of E. coli and S. auratus was 80 mg/ L and 120 mg/ L, respectively, and the minimum bactericidal concentration (MBC) was 50 mg/ L and 100 mg/ L, respectively. At the same time, the composite material has good biocompatibility under the concentration of 50 mg/ L. Ag/ Fe _ 3O _ 4/ rGO material was prepared by two-step method. Fe _ 3O _ 4/ rGO was prepared by using GO as the carrier, AgNO _ 3 and ferrous chloride (FeCl _ 2 路 4H _ 2O) as the metal precursor and NaBH _ 4 as the reducing agent, and Ag was further introduced, finally the Ag/ Fe _ 3O _ 4/ rGO composite was obtained. The results show that the feed ratio of the metal precursor is an important factor to control the microstructure of the composite. When the molar ratio of Ag ~ + to Fe2 + is 1: 2, the nano-particles are uniformly supported, the average particle size of Fe _ 3O _ 4 nanoparticles is 10 nm, and the AgNPs are spherical. The particle size concentration is within 20 nm. The magnetic properties of the composite material prepared by the process are as follows: the saturation magnetic susceptibility is 24. 7 Am ~ 2/ kg, the MIC values of E. coli and S. auratus are 50 mg/ L and 80 mg/ L, respectively, and MBC values are 30 mg/ L and 50 mg/ L, respectively. At the same time, the composite material has good biological safety. AgFe/ 3-D graphene (AgFe/ GCM) was prepared by chemical reduction-gel reaction. AgNO _ 3, Fe (NO _ 3) _ 3 路 9H _ 2O solution were mixed with GO suspension, treated with NaBH _ 4 and ascorbic acid, reacted at 90 鈩，
本文编号：2261328
[Abstract]:Silver and AgNPs have been widely used in people's daily life due to their excellent antibacterial performance, antimicrobial resistance and high safety, such as food preservation, food preservation, cosmetics, disinfectants and water treatment materials, which play a great role in protecting human health. However, AgNPs can easily lead to rapid Ag loss due to high activity and poor stability, which not only reduces the antibacterial performance of AgNPs, increases the cost, but also can produce heavy metal pollution. In order to solve these problems, using the specific surface area of graphene oxide (GO), GO as a carrier, uniformly dispersing Ag-based nanoparticles, improving its antibacterial property, introducing Fe element (Fe), preparing composite material with magnetic properties, and facilitating the recovery and use of the material. By constructing the reduced graphene oxide (rGO) loaded AgFe or Ag/ Fe _ 3O _ 4 nano-particle composite material, a new kind of new material was obtained. The effects of preparation process parameters on composition, composition, microstructure and structure of composite materials are studied in detail, and the relationship between microstructure and antibacterial, sterilization and biocompatibility of composite materials is studied. high antibacterial performance and good biocompatibility can be obtained, and the controllable synthetic process parameters are obtained. The main contents are as follows: 1. AgFe/ r GO composite was prepared by in situ growth method. The AgFe/ rGO composite was prepared by one-step reaction with GO as carrier, silver nitrate (AgNO _ 3) and nine-water ferric nitrate (Fe (NO _ 3) _ 3 路 9H _ 2O) as the metal precursor, and the AgFe/ rGO composite was prepared by one-step reaction. E. coli and Staphylococcus aureus (S. auratus) were the experimental strains, and the antibacterial properties of the composites were studied. The results show that the pH value of the reaction solution and the feeding ratio of the metal precursor are important factors for regulating the microstructure of the composite material. When the pH is 9. 5, the molar ratio of Ag ~ + to Fe ~ (3 +) is 1: 1, the nano-particles have AgFe alloy structure, and the morphology of the particles is uniform. The size was small (~ 5 nm), and the dispersity was high in the rGO layer. The minimum inhibitory concentration (MIC) of E. coli and S. auratus was 80 mg/ L and 120 mg/ L, respectively, and the minimum bactericidal concentration (MBC) was 50 mg/ L and 100 mg/ L, respectively. At the same time, the composite material has good biocompatibility under the concentration of 50 mg/ L. Ag/ Fe _ 3O _ 4/ rGO material was prepared by two-step method. Fe _ 3O _ 4/ rGO was prepared by using GO as the carrier, AgNO _ 3 and ferrous chloride (FeCl _ 2 路 4H _ 2O) as the metal precursor and NaBH _ 4 as the reducing agent, and Ag was further introduced, finally the Ag/ Fe _ 3O _ 4/ rGO composite was obtained. The results show that the feed ratio of the metal precursor is an important factor to control the microstructure of the composite. When the molar ratio of Ag ~ + to Fe2 + is 1: 2, the nano-particles are uniformly supported, the average particle size of Fe _ 3O _ 4 nanoparticles is 10 nm, and the AgNPs are spherical. The particle size concentration is within 20 nm. The magnetic properties of the composite material prepared by the process are as follows: the saturation magnetic susceptibility is 24. 7 Am ~ 2/ kg, the MIC values of E. coli and S. auratus are 50 mg/ L and 80 mg/ L, respectively, and MBC values are 30 mg/ L and 50 mg/ L, respectively. At the same time, the composite material has good biological safety. AgFe/ 3-D graphene (AgFe/ GCM) was prepared by chemical reduction-gel reaction. AgNO _ 3, Fe (NO _ 3) _ 3 路 9H _ 2O solution were mixed with GO suspension, treated with NaBH _ 4 and ascorbic acid, reacted at 90 鈩，
本文编号：2261328
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