碱处理载银NaA分子筛的制备及抗菌性能研究

本研究以碱处理NaA分子筛为载体,选取Ag<'+>为抗菌成分,通过液相离子交换法,制备了碱处理载银NaA分子筛抗菌剂.采用XRD、BET和ICP等手段对样品的结构和载银量等性质进行了表征,并考察了样品的缓释性能、抗变色性能及抗菌性能等.结果表明:碱处理NaA分子筛保持了原有的分子筛骨架结构,Si/Al比值下降到1.1,...     

反应温度对蒙脱石载银量及其缓释性能的影响

以钠基蒙脱石(Na-MMT)为载体,氧化银与氨水反应形成的银氨络合物[Ag(NH₃)₂OH]为前驱体,通过离子交换和三乙醇胺(TEA)还原两步法制备了载银蒙脱石(Ag-MMT)。 用佛尔哈德法测定了载银蒙脱石(Ag-MMT)的载银量,探讨了反应温度对MMT 载银量及其缓释性能的影响,并用FI-IR、XRD等技术手段对Na-MMT和Ag-MMT的结构进行了表征。 结果表明,在蒙脱石与Ag⁺的质量比为20:1、离子交换时间为1 h、反应温度50 ℃,然后再加入三乙醇胺和聚乙烯吡咯烷酮,50 ℃下反应2 h,MMT的载银量最大,银的利用率达到86.89%,释放时间最持久,并且MMT的层状结构没有被破坏。     

邻苯二甲酸在苯并三氮唑银为银源的光敏热显影体系中的作用

本文研究了邻苯二甲酸(H₂PA)的用量以及H₂PA的阴离子和阳离子对以苯并三氮唑银为银源的光敏热显影体系的影响.结果表明,在苯并三氮唑银体系中,邻苯二甲酸(H₂PA)的阳离子(H⁺)降低了体系的pH值,还原剂的显影活性和H₂PA与银离子的络合能力;而其阴离子(PA^2-)则与苯并三氮唑银生成中间体,起到传输银离子的作用.     

磷腈-紫精聚合物的合成与电致变色性能

以六氯环三磷腈作为核心、 紫精为电致变色活性基, 合成了一种新型有机-无机杂化电致变色材料——六(1-乙基-4,4'-联吡啶-甲基苯氧基)环三磷腈(PHV ²⁺). 通过傅里叶变换红外光谱(FTIR)、 X射线衍射(XRD)及核磁共振氢谱( ¹H NMR)表征了PHV ²⁺的结构. 优良的水溶性使得该化合物可以通过简单的方法构造一个以聚乙烯醇(PVA)为凝胶基质的电致变色水凝胶, 具有成本低廉及无毒害的优点. 以氟掺杂氧化锡(FTO)涂层玻璃作为电极材料, PHV ²⁺作为电致变色材料制备了PHV ²⁺/PVA/KCl电致变色器件(PHV ²⁺/PVA/KCl ECD). 该电致变色器件在2.1 V电压下由淡黄色变为紫色, 颜色变化明显, 并且该颜色变化可以循环500次; 器件在526 nm处的光学对比度达到62.19%. 良好的电致变色性质使该化合物在电致变色器件方面具有潜在应用价值.     

载银缓释型抗菌敷料

近10年来,载银缓释型抗菌敷料因其优良特性,在医药、卫生等领域引起科学家们的广泛关注。本文综述了银的抗菌机理和载银缓释型抗菌敷料的缓释机制;重点介绍了目前在国际市场上销售的代表性载银缓释型抗菌敷料的性能,并从不同的载体材料角度(如生物高分子、合成高分子、生物和合成高分子共用、有机硅材料)总结了新型载银抗菌敷料的研究进展;最后,讨论了载银抗菌医用敷料在研究和应用中需要解决的问题。     

Ag/TiO2光催化氧化还原反应脱除水体中无机氮

采用光催化还原法制备了高活性的载银二氧化钛光催化剂,并用XRF、TEM、XRD及XPS、UV-Vis方法对催化剂进行了表征.考察了负载Ag的含量、催化剂制备时间、搅拌气体的种类以及Fe²⁺的添加等条件对该催化剂光催化水体脱氮活性的影响.结果表明:载银量1.0%时去除效果最佳;制备催化剂时光照时间不充分会使催化剂失去还原效力;氮气保护下催化剂反应活性更高;Fe²⁺的加入利于光催化反应;2 h光催化含氨氮和亚硝基氮的水样,总脱氮率达到了63.9%.     

载银油茶果壳抗菌剂的制备和性能

考察银离子浓度、pH、温度、时间等制备条件对油茶果壳载银抗菌剂性能的影响,并考察了材料对大肠杆菌、金黄色葡萄球菌的抑制效果。结果表明:油茶果壳载银抗菌剂的最佳制备条件为吸附时间6 h,搅拌温度35℃,pH=4,银离子浓度是0.2 mol/L,制备的油茶果壳载银抗菌剂对大肠杆菌、金黄色葡萄球菌具有优异的抗菌性能。     

一步法制备PNIPAAm-g-PAN/PSt载银复合微球及其抗菌性能研究

以AgNO3为金属源,通过乙醇将与聚N-异丙基丙烯酰胺接枝聚丙烯腈/聚苯乙烯（PNIPAAm-g-PAN/PSt）聚合物微球表面酰胺基团配位的银离子（Ag+）还原,一步法制备了PNIPAAm-g-PAN/PSt载银复合微球。通过傅立叶变换红外（FTIR）和紫外-可见光光谱表征发现,由Ag+还原所得的Ag纳米颗粒被成功地固载在PNIPAAm-g-PAN/PSt 微球上;用透射电子显微镜（TEM）对载银微球的大小和形态进行了表征;热重分析（TGA）结果表明,固载在微球表面的银纳米颗粒的含量（质量分数）为12%;抗菌实验结果表明,所制备的载银微球具有抗革兰氏阴性菌的活性。     

ss-DNA在纳米金上固载和杂化的电化学传感研究

将2-氨乙基硫醇(AET)固载到玻碳电极(GCE)表面,进而化学吸附纳米金(NG),并在纳米金上固载ss-DNA得到ss-DNA/NG/AET/GCE,以Co(bpy)₃³⁺为电化学指示剂可以识别研究ss-DNA的杂化反应.结果表明,纳米金能使固载其上的ss-DNA发生部分变性而结合Co(bpy)₃³⁺,但用pH7.0的磷酸缓冲液浸泡可基本上避免这种变性,并明显提高杂化反应的识别能力.结合在ds-DNA/NG/AET/GCE上的Co(bpy)₃³⁺的峰电流与扫速的线性关系可保持到80mV/s.与电沉积法固载纳米金相比较,本电极更稳定和可靠.     

塑料表面载银微凝胶层层组装膜的制备及抗菌活性

以载银聚烯丙基胺盐酸盐-葡聚糖微凝胶与聚苯乙烯磺酸钠为构筑基元,利用层层组装技术制备了一种可直接沉积在疏水的塑料基底表面的载银抗菌微凝胶膜. 研究结果表明,该载银抗菌微凝胶膜具有很好的抗菌能力,并且其抗菌活性可以通过控制载银微凝胶膜的组装层数方便地进行调控. 这种制备在塑料表面的载银抗菌微凝胶膜具有良好的稳定性和基底粘附力,能够保障其长效抗菌的实现.     

Antibacterial activity of silver bionanocomposites synthesized by chemical reduction route

ABSTRACT: BACKGROUND: The aim of this study is to investigate the functions of polymers and size of nanoparticles on the antibacterial activity of silver bionanocomposites (Ag BNCs). In this research, silver nanoparticles (Ag NPs) were incorporated into biodegradable polymers that are chitosan, gelatin and both polymers via chemical reduction method in solvent in order to produce Ag BNCs. Silver nitrate and sodium borohydride were employed as a metal precursor and reducing agent respectively. On the other hand, chitosan and gelatin were added as a polymeric matrix and stabilizer. The antibacterial activity of different sizes of silver nanoparticles was investigated against Gram-positive and Gram-negative bacteria by the disk diffusion method using Mueller-Hinton Agar. RESULTS: The properties of Ag BNCs were studied as a function of the polymer weight ratio in relation to the use of chitosan and gelatin. The morphology of the Ag BNCs films and the distribution of the Ag NPs were also characterized. The diameters of the Ag NPs were measured and their size is less than 20 nm. The antibacterial trait of silver/chitosan/gelatin bionanocomposites was investigated. The silver ions released from the Ag BNCs and their antibacterial activities were scrutinized. The antibacterial activities of the Ag BNC films were examined against Gram-negative bacteria (E. coli and P. aeruginosa) and Gram-positive (S. aureus and M. luteus) by diffusion method using Muller-Hinton agar. CONCLUSIONS: The antibacterial activity of Ag NPs with size less than 20 nm was demonstrated and showed positive results against Gram-negative and Gram-positive bacteria. The Ag NPs stabilized well in the polymers matrix.     

Preparation and Antibacterial Effect of Bamboo Charcoal/Ag on Staphylococcus Aureus and Pseudomonas Aeruginosa

Bamboo charcoal supporting silver (BC/Ag) was prepared by activation and chemical reduction. The BC/Ag composites were characterized by silver particle size and distribution, silver ion (Ag⁺) release and antibacterial properties. Scanning and transmission electron microscopy (SEM and TEM) showed that the Ag particles were distributed uniformly on the BC matrix. The Ag particle size was found to be less than 150 nm based on TEM. The Ag⁺ release increased initially which was followed by a marginal increase between the 8th and 24th hour. Composites contained higher amounts of silver exhibited a further rise in Ag⁺ release from the 24‐hours of storage in water. The antibacterial effects of the BC/Ag composite powders against Pseudomonas aeruginosa and Staphylococcus aureus were assessed from the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) method, and an excellent antibacterial performance was discovered.     

Antibacterial properties of polyaniline-silver films

In situ polymerised thin polyaniline (PANI) films produced on polystyrene dishes were tested for their antibacterial activity with respect to Escherichia coli and Staphylococcus aureus, representing both gram-positive and gram-negative bacteria. PANI films were subsequently used for the reduction of silver ions to metallic Ag. PANI salt and base in original forms and after the deposition of Ag were studied. PANI salt showed a significant antibacterial effect against both bacteria strains while the efficacy of neat PANI base was only marginal. After the Ag deposition, the PANI base exhibited different levels of antibacterial effect depending on the type of the bacterial strain; the growth of gram-positive Staphylococcus aureus was inhibited depending on the Ag concentration on the film, while Escherichia coli remained uninfluenced. Efficacy of the PANI salt with deposited Ag against both bacteria strains was comparable with that of PANI alone and was not affected by the Ag concentration. The results show that Ag deposition can be a suitable method for the preparation of PANI base films with improved antibacterial properties.     

水溶性银纳米颗粒的制备及抗菌性能

采用液相还原法, 以单宁酸为还原剂, 聚乙烯吡咯烷酮(PVP)为修饰剂制备出了水溶性的表面修饰Ag纳米颗粒. 通过X 射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、紫外-可见吸收分光光度计(UV-Vis)、傅里叶变换红外(FTIR)光谱仪等对所得样品的形貌和结构进行了表征. 采用肉汤稀释法测试了样品的抗菌性能, 考察了样品在水相中的分散稳定性, 提出了PVP修饰Ag纳米颗粒的形成机理. 结果表明所制备的样品具有Ag的面心立方晶体结构, 平均粒径为15-17 nm. 样品在水相中能长时间稳定分散; 对埃希氏大肠杆菌(E. coli)、金黄色葡萄球菌(S. aureus)具有明显的抗菌作用. 操作简便、条件温和的制备方法易于在工业规模上放大; 试剂无毒, 使得所制备的PVP修饰Ag纳米颗粒作为抗菌剂具有良好的应用前景.     

Antibacterial thermoplastic polyurethane electrospun fiber mats prepared by 3-aminopropyltriethoxysilane-assisted adsorption of Ag nanoparticles

Antibacterial thermoplastic polyurethane(TPU) electrospun fiber mats were prepared by adsorption of Ag nanoparticles(Ag NPs) onto TPU/3-aminopropyltriethoxysilane(APS) co-electrospun fiber mats from silver sol. The use of APS can functionalize TPU fibers with amino groups, facilitating the adsorption of Ag NPs. The effects of p H of silver sol and APS content on Ag NP adsorption and antibacterial activity were investigated. Ag NP adsorption was evidenced by TEM, XPS and TGA. Significant Ag NP adsorption occurred at p H = 3-5. The main driving force for Ag NP adsorption is electrostatic interaction between ―NH3~+ of the fibers and ―COO-derived from the ―COOH group capped on the surfaces of Ag NPs. The antibacterial activity of the Ag NP-decorated TPU/APS fiber mats was investigated using both gram-negative Escherichia coli and gram-positive Bacillus subtilis. The antibacterial rate increases with increasing APS content up to 5% where the antibacterial rates against both types of bacteria are over 99.9%.     

Ag(Ⅲ)-聚六亚甲基双胍配合物的合成及抗菌性能表征

采用水溶液反应法,以不同粘均相对分子质量的聚六亚甲基双胍(PHMB)作为配体,合成出一系列稳定的由400 nm左右的小颗粒团聚而来的微米级四配位Ag(Ⅲ)-PHMB配合物,并对其进行表征证明了物质的结构与价态。通过抗菌活性实验发现,Ag(Ⅲ)-PHMB配合物的抗菌活性随着配体PHMB的粘均相对分子质量的升高而增大,随着粒径增大而减小。在低浓度条件下,微米级Ag(Ⅲ)-PHMB配合物的抗菌性能高于同等质量浓度的AgO、AgNO_3与PHMB;随着质量浓度的升高,微米级Ag(Ⅲ)-PHMB配合物与细菌的实际接触面积、缓释出的抗菌活性物质增长趋缓,因而抗菌活性升高趋缓。     

Ag/Fe_3O_4/rGO纳米复合材料的制备及抗菌性能

以四水合氯化亚铁和硝酸银为原料,硼氢化钠为还原剂,氧化石墨烯(GO)为载体,通过原位还原法制备了具有磁分离功能的银/四氧化三铁/还原氧化石墨烯(Ag/Fe_3O_4/rGO)纳米复合抗菌材料.采用X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)、透射电子显微镜(TEM)等对复合材料进行了表征.结果显示,Fe_3O_4和Ag纳米颗粒均匀分布在rGO片层上.复合材料的饱和磁化率(Ms)为40.5 A·m~2·kg·(-1),表明其具有较强的磁性,将其与菌液混合后,在磁场作用下10 min即可吸附沉降完成磁分离.以大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)为实验菌株,通过琼脂扩散法评价了复合材料的抗菌性能.结果表明,该复合材料具有良好的抗菌效果,对E.coli和S.aureus的抑菌圈直径分别为18 mm和13 mm,最低抑菌浓度值(MIC)分别为50 mg/L和80 mg/L,最低杀菌浓度值(MBC)分别为30 mg/L和50 mg/L.     

通过柠檬酸改性提高载银活性炭的抗菌性能

通过负载柠檬酸对活性炭进行改性,用N2吸附法测定活性炭的比表面积,用AAS、SEM、XRD测试技术分析了银在活性炭上的吸附和分布,并研究了载银活性炭的抗菌性能。结果表明,负载柠檬酸使活性炭的比表面积下降约24%,但载银后活性炭的比表面积增大。柠檬酸改性为[Ag(NH3)2] 的还原吸附提供更多的活性点,使银的吸附速率加快,吸附量提高约25%,表面的银颗粒变得非常密集,粒径减小,且颗粒均匀,因此抗菌性能显著增强,其中对金黄色葡萄球菌的杀灭效果明显优于对大肠杆菌的,同时对于高分散Ag/C催化剂的制备及银的回收也具有重要的价值。     

稀土氮杂环配合物的合成、 结构及抑菌活性

采用溶液合成法, 在室温下合成了一系列稀土配合[Ln(IAA)₂(phen)₂]·(NO₃)[Ln=Ce(1), Gd(2), Tb(3), Dy(4), Ho(5), HIAA=吲哚乙酸, phen=1,10-菲咯啉], 并通过元素分析、 红外光谱、 热重分析、 X射线单晶衍射、 X射线粉末衍射等方法对配合物进行了表征. 结果表明, 配合物15具有相同的结构, 对配合物2的单晶结构分析表明, 配合物2为超分子网络结构, 通过分子间氢键形成2D网络, 中心金属Gd(Ⅲ)为九配位, 具有单帽四方反棱柱几何构型. 此外, 对该系列配合物进行了抑菌活性的研究, 得到了抑菌活性与配合物组成的构效关系.     

An Antibacterial Nonenzymatic Glucose Sensor Composed of Carbon Nanotubes Decorated with Silver Nanoparticles

A glucose sensor composed of silver nanoparticles decorated carbon nanotubes (Ag‐NPs/CNTs) prepared by ion implantation is described. Ag‐NPs with size of 2–4 nm are uniformly distributed in the CNTs after ion implantation. This process provides a strong combination between Ag‐NPs and CNTs and can effectively prevent the Ag‐NPs from aggregation. A linear range of 125 µM to 10 mM towards glucose determination was obtained. The Ag‐NPs/CNTs electrode shows minimal interferences from co‐existence species such as uric acid and ascorbic acid and an antibacterial rate of 94 % towards E. coli.