【摘要】：納米銀(Silver nanoparticles,AgNPs)由于其優(yōu)異的抗菌性能、抗菌的廣譜性和高安全性,被廣泛應(yīng)用于人們?nèi)粘Ｉ钪?如眼藥水、食品保藏、化妝品、消毒劑和水處理材料等,對保護人類的健康發(fā)揮著巨大的作用。然而,AgNPs由于活性高,穩(wěn)定性較差,因此容易造成Ag快速流失,這不僅會降低AgNPs的抗菌性能,增加成本,還可能會產(chǎn)生重金屬污染。針對這些難題,本文利用氧化石墨烯(graphene oxide,GO)大的比表面積,以GO為載體,均勻分散Ag基納米粒子,提高其抗菌性能,引入鐵元素(Fe),制備具有磁性的復(fù)合材料,便于抗菌材料的回收使用,通過構(gòu)筑還原氧化石墨烯(reduced graphene oxide,rGO)負載AgFe或Ag/Fe_3O_4納米粒子復(fù)合材料,獲得可分離的新型抗菌材料。詳細研究制備工藝參數(shù)對復(fù)合材料的組成、組分以及微觀形貌和結(jié)構(gòu)的影響規(guī)律,重點研究復(fù)合材料的微觀結(jié)構(gòu)與抗菌、殺菌以及生物相容性之間的聯(lián)系,獲得高抗菌性能和良好生物相容性的可分離的新型抗菌材料以及其可控合成的工藝參數(shù)。主要研究內(nèi)容如下:1.采用原位生長法制備AgFe/r GO復(fù)合材料。以GO為載體,硝酸銀(AgNO_3)和九水硝酸鐵(Fe(NO_3)_3·9H_2O)為金屬前驅(qū)體,硼氫化鈉(NaBH_4)為還原劑,通過一步反應(yīng)制備AgFe/rGO復(fù)合材料,以格蘭氏陰性菌大腸桿菌(Escherichia coli,E.coli)和格蘭氏陽性菌金黃色葡萄球菌(Staphylococcus aureus,S.aureus)為實驗菌株,研究復(fù)合材料的抗菌性能。結(jié)果表明,反應(yīng)溶液的pH值和金屬前驅(qū)體投料比是調(diào)控復(fù)合材料微觀結(jié)構(gòu)的重要因素,當pH為9.5,Ag~+與Fe~(3+)摩爾比為1:1時制備的復(fù)合材料中納米粒子具有AgFe合金結(jié)構(gòu),粒子形貌均一,尺寸小(~5 nm),在rGO片層中分散度高。該工藝條件制備的復(fù)合材料具有優(yōu)異的抗菌性能,其對E.coli和S.aureus的最低抑菌濃度(Minimum inhibitory concentration,MIC)分別為80 mg/L和120 mg/L,最低殺菌濃度(Minimum bactericidal concentration,MBC)分別為50 mg/L和100 mg/L。同時,該復(fù)合材料在50 mg/L濃度以下時,具有良好的生物相容性。2.采用兩步法制備Ag/Fe_3O_4/rGO新型抗菌材料。以GO為載體,AgNO_3和四水氯化亞鐵(FeCl_2·4H_2O)為金屬前驅(qū)體,NaBH_4為還原劑,先制備Fe_3O_4/rGO,再進一步引入Ag,最終獲得Ag/Fe_3O_4/rGO復(fù)合材料。結(jié)果表明,金屬前驅(qū)體投料比是調(diào)控復(fù)合材料微觀結(jié)構(gòu)的重要因素,當Ag~+與Fe2+摩爾比為1:2時制備的復(fù)合材料中納米顆粒均勻負載,Fe_3O_4納米顆粒平均粒徑為10 nm,AgNPs呈類球形,顆粒尺寸集中分布在20 nm以內(nèi)。該工藝條件制備的復(fù)合材料集磁性能與抗菌性能于一體,其飽和磁化率為24.7 Am~2/kg,可以被磁鐵吸引,對E.coli和S.aureus的MIC值分別為50 mg/L和80 mg/L,MBC值分別為30 mg/L和50 mg/L。同時,該復(fù)合材料具有良好的生物安全性。3.采用化學(xué)還原-凝膠反應(yīng)法制備AgFe/三維石墨烯(AgFe/graphene cellular monolith,AgFe/GCM)新型抗菌材料。將AgNO_3、Fe(NO_3)_3·9H_2O溶液與GO懸浮液混合,經(jīng)NaBH_4和抗壞血酸處理,在90℃環(huán)境下反應(yīng)4 h使反應(yīng)物組裝成凝膠材料,冷凍干燥即得AgFe/GCM復(fù)合材料。結(jié)果表明,反應(yīng)前驅(qū)體中Ag~+與Fe~(3+)摩爾比對復(fù)合材料形貌結(jié)構(gòu)和顆粒負載具有重要影響,當比例為1:1時制備的復(fù)合材料孔道結(jié)構(gòu)明顯,AgFe納米顆粒均勻負載。對E.coli和S.aureus的MIC值分別為50 mg/L和100 mg/L,MBC值分別為30 mg/L和50 mg/L,用氣凝膠對細菌進行5次過濾,其殺滅比例約為70%,抗菌性能結(jié)果表明,該復(fù)合材料在水過濾殺菌方面具有潛在的應(yīng)用價值。此外,Fe的加入,降低了Ag~+釋放速度,使復(fù)合材料能夠長時間的釋放Ag~+來殺菌。復(fù)合材料濃度為50 mg/L時,細胞存活率是85%,具有優(yōu)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，

本文編號：2261328