木质素-聚吡咯复合纳米粒子的制备及其Ag+吸附性能

以酶解木质素和吡咯单体为原料,通过原位聚合法制备了木质素-聚吡咯(EHL-PPY)复合纳米粒子。而后以银离子为吸附质,系统地研究了EHL-PPY复合纳米粒子的银离子吸附性能,考察了吸附剂浓度,吸附时间和银离子初始浓度对吸附容量和吸附率的影响。在35℃时,该复合纳米粒子对银离子的饱和吸附容量为882.0 mg/g,吸附完成后,银离子被还原为直径为22~56 nm的单质银颗粒。研究表明,EHL-PPY复合纳米粒子可作为低成本银离子吸附剂使用。     

石墨烯-银纳米粒子复合材料的制备及表征

以无毒、绿色的葡萄糖为还原剂, 在没有稳定剂、温和的液相反应条件下, 同时还原氧化石墨和银氨溶液中的银氨离子, 原位制备石墨烯-银纳米粒子复合材料. 采用X射线衍射、红外吸收光谱、拉曼光谱、扫描电镜和透射电子显微镜对所制备的石墨烯-银纳米粒子复合材料进行了表征. 结果表明: 氧化石墨和银离子在反应过程中同时被葡萄糖还原, 银纳米粒子均匀分布于石墨烯片层之间, 生成的银纳米粒子中大多数存在着孪晶界, 银纳米粒子的大小和分布受硝酸银用量的影响, 在合适的银离子浓度下, 负载在石墨烯片层上的银纳米粒子的粒径分布集中在25 nm左右; 复合材料中石墨烯的拉曼信号由于银粒子的存在增强了7倍.     

活性炭纤维对铂(Ⅳ)的还原吸附及其影响因素的研究

载铂活性炭纤维在燃料电池催化材料的制备等方面具有重要的应用前景.本文比较了水蒸汽活化和磷酸或氯化锌活化活性炭纤维对水溶液中铂离子的还原吸附性能,并研究了影响活性炭纤维对铂的还原吸附的几种因素.结果表明,不同工艺制备的活性炭纤维,由于其电极电位的差异,其对铂离子的吸附容量也不同;水蒸汽活化和氯化锌活化活性炭纤维由于具有低的电极电位,因而表现出对铂离子更大的还原倾向,在吸附的初期,表现出更快的吸附速度.纤维状的活性炭纤维比颗粒状的活性炭具有更快的吸附速度.溶液的酸度也显著影响活性炭纤维对铂离子的还原吸附能力;低的pH下,活性炭纤维对铂一般具有更强的还原吸附容量.     

活性炭纤维对贵金属的吸附

活性炭纤维（ACF）具有优越的氧化还原吸附特性，通过创麻基活性炭纤维（水蒸气活化和磷酸化学活化）与硝酸银溶液反应而将银引入纤维中，X射线衍射分析表明ACF上负载的都是纳米银热处理可使它们的畸变减小且在高于150℃时才长大此外，用其它基体的ACF也可还原吸附贵金属离子（Au+、Pt4+、Pd2＋），并得到晶体生长有取向的纳先资金属粒子复合的活性炭纤维     

纳米银的生物制备及应用进展

阐述了银纳米颗粒在催化剂制备、抗菌材料及电子浆料等领域的应用。综述了生物还原法制备纳米银的研究进展,主要包括用于生物吸附及生物还原银离子的微生物材料和生物吸附还原银离子的相关机理。     

几类载银活性炭纤维抗菌活性的比较

利用水蒸汽活化和化学活化方法，制备了各种原料基活性炭纤维，并利用活性炭纤维的氧化还原特性，在其上负载金属银。研究并比较了这些载银活性炭纤维对大肠杆菌的杀灭作用。结果表明，原料基、活化方法、载银量、纤维的比表面积等因素均对材料的抗菌性能有一定的影响。磷酸活化的活性炭纤维表现出强的抗菌杀菌能力；载银量和比表面积越大，其灭菌能力越强；在适当载银量时，磷酸活化活性炭纤维可在短时间内将高浓度细菌基本杀灭。     

高邻位热固性酚醛基纳米活性炭纤维膜的制备及吸附性能

以合成的高邻位热塑性酚醛为模板,通过与甲醛的加成反应制备了高邻位热固性酚醛树脂,经溶液静电纺丝、盐酸溶液固化获得了纳米酚醛纤维,最终利用KOH活化获得了高邻位热固性酚醛基纳米活性炭纤维。利用红外光谱、X射线衍射、热重分析和扫描电镜分析了制备物的结构、性能变化,并观察了纳米纤维的表面形貌;通过比表面积和亚甲基蓝(MB)/碘吸附分析了纳米活性炭纤维的孔结构和吸附性能,获得了比表面2606 m~2/g、MB吸附量1643.0 mg/g、碘吸附量2731.1 mg/g的高邻位热固性酚醛基纳米活性炭纤维,实现了低污染、高活性纳米炭纤维的制备。     

载贵金属活性碳纤维对氙吸附性能的研究

利用活性炭纤维的氧化还原特性,在活性炭纤维上负载了一定量的贵金属银或金。表征了负载贵金属后活性炭纤维的孔结构变化,以及活性炭纤维表面贵金属颗粒的分布和表面化学性质。研究并比较了负载贵金属后活性炭纤维对氙的吸附性能。研究结果表明,在活性炭纤维上负载适量的贵金属银或金,可以显著地提高活性炭纤维对氙的吸附容量,其可能的原因是由于这些贵金属对活性炭纤维孔宽和表面化学性质的修饰,以及提高了活性炭纤维对氙的吸附势。     

还原氧化石墨烯-贵金属纳米复合物的制备及表征

以氧化石墨和氯铂酸为前驱体,在油胺中简便地合成了还原氧化石墨烯-铂(Reduced graphene oxide-platinum,rGOPt)纳米复合物,并对其进行了表征。透射电子显微镜和光谱测试结果表明,铂纳米颗粒均匀分布在石墨烯表面,尺寸约为30nm,铂纳米粒子为多孔隙结构,结晶性能良好,氧化石墨在高温下转变为还原氧化石墨烯。用此方法也可以制备还原氧化石墨烯-金(rGO-Au)或还原氧化石墨烯-银(rGO-Ag)的纳米复合物,金、银纳米颗粒呈球状,对可见光具有明显的表面等离子吸收。同时,油胺作为溶剂、贵金属盐的还原剂和表面活性剂,使制备过程简单、快捷。     

稻壳基活性炭负载镍催化剂的制备及在香草醛加氢脱氧反应中的催化性能

以稻壳活性炭作为碳源,硝酸镍为金属前驱体,采用浸渍法结合碳热还原和催化石墨化的方法制备了具有良好香草醛加氢脱氧催化性能的稻壳基活性炭负载镍催化剂。在催化剂的制备过程中,稻壳活性炭作为金属前驱体的还原剂,金属镍作为稻壳活性炭催化石墨化的催化剂。以生物油模型化合物香草醛加氢脱氧制备4-甲基愈创木酚为探针反应,考察制得催化剂的加氢脱氧反应性能。采用X射线衍射、高分辨透射电镜、拉曼光谱仪、氮气吸附仪等手段对催化剂中Ni的价态、粒径和分散情况,石墨化程度、比表面积、孔径等进行表征。结果表明,催化剂的结构和其催化性能存在密切联系。随着碳热还原温度的升高,催化剂的催化活性出现了先降低而后提高的趋势。这是由于较高的碳热还原温度引起镍纳米粒子的聚集和长大,不利于其催化性能;同时较高的碳热还原温度促使催化剂石墨化程度的提高,对其催化性能起到促进作用。     

活性碳纤维载银工艺及其表面银颗粒的形态特征

以自制粘胶基活性碳纤维（ＡＣＦ）为载体，通过真空浸渍和真空热分解的方法在其表面沉积银，制得了载银活性碳纤维（ＡＣＦ（Ａｇ）。研究了载银工艺参数对ＡＣＦ（Ａｇ）的银含量、表面银颗粒大小、分布及形态的影响规律，提出了银颗粒的形核与长大机制；此外，还分析了银颗粒与ＡＣＦ结合力的影响因素。     

Structure and antibacterial activity of silver-supporting activated carbon fibers

In this paper, several kinds of silver supporting activated carbon fibers (ACF-Ag) were prepared by the reduction adsorption on activated carbon fiber (ACF) activated with steam or H₃PO₄ using sisal, viscose and pitch fiber as precursors. Their pore structure and surface chemistry were characterized using nitrogen adsorption, XPS, WXRD and ICP quantitative analysis. Their antibacterial activities were tested. The results showed that metallic silver particle in micron or nano-scale size could be easily and dispersedly supported onto the surface of ACF using reduction property of ACF without largely decreasing their specific surface area. The ACF-Ag showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The antibacterial activity has closed relationship with the precursors, the method of activation, silver content and the specific surface area of the ACFs. Generally, higher silver content and higher specific surface area provide the materials stronger antibacterial activity. ACF activated with phosphoric acid, due to the presence of certain amount of organic phosphoric groups on the surface, showed stronger antibacterial activity than those activated with steam. The antibacterial materials can be easily regenerated without decreasing their antibacterial activity and without releasing large amount of silver from the solid phase.     

聚苯乙烯-银胶体晶体的制备及自组装行为

利用冠醚可与银离子复合的特性,制备了聚苯乙烯-冠醚乳胶粒,采用原位还原的方法在乳胶粒表面引入银纳米颗粒,通过垂直沉降,乳胶粒子可自组装成紧密堆积具有面心立方的聚苯乙烯-银胶体晶体。结果表明:引入聚苯乙烯-银乳胶粒表面的银为胶粒总质量的6.7%,乳胶粒具有以银纳米颗粒为壳,聚苯乙烯为核的核壳结构,乳胶粒大小为260 nm,并具有很好的单分散性。由于Bragg散射,该胶体晶带隙位于580 nm,在可见光区域产生明显的光子带隙而呈现出亮丽的绿色。     

Reduction–adsorption behavior of platinum ions on activated carbon fibers

A number of activated carbon fibers (ACF) were prepared by activation with steam, Phosphoric acid, or Zinc Chloride. Their reduction-adsorption behavior for Pt(IV) was studied using scanning electron microscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy. The results show that Pt ions in solution can be adsorbed by ACFs and reduced to metallic platinum. The reduction–adsorption capacity of ACF for Pt could be greater than 200 mg/g. Generally, higher specific surface area or lower electrode potential produces a higher capacity. Most of the adsorbed platinum ions were reduced into metallic platinum, and about 25% of platinum atoms remained as Pt(II) or Pt(IV). XRD examination showed that the Pt particles on the ACF surface were crystallized when heated to 673 K.     

银型抗菌活性碳纤维的结构及其抗菌性能的研究

利用活性碳纤维的高效吸附性能 ,通过浸渍法把银、银盐等金属或金属化合物吸附沉积在活性碳纤维上 ,并对其进行适当处理 ,制备出含细小银化合物或金属银颗粒的活性碳纤维。利用扫描电镜 ,X 射线衍射 ,ICP发射光谱等分析测定方法研究了银型抗菌活性碳纤维的结构。研究了这类银型抗菌活性碳纤维对大肠埃氏杆菌 (Escherichiacoli)和金黄色葡萄球菌 (Staphylococlusaureus)的杀灭效果。结果表明 ,这类银型抗菌活性碳纤维对大肠杆菌和金黄色葡萄球菌均有很强的杀灭能力 ,经其处理后 ,水中的大肠杆菌和金黄色葡萄菌被完全杀灭。对每次使用后被洗脱的银含量测定表明 ,水中所含银浓度低于饮水标准的要求     

The bio-inspired approach to controllable biomimetic synthesis of silver nanoparticles in organic matrix of chitosan and silver-binding peptide (NPSSLFRYLPSD)

Inspired by organic matrices in some life systems which can operate as templates for biosynthesis organic materials with uniform size and morphology, in our experiment, chitosan was combined with AG4 peptide (NPSSLFRYLPSD) to form a simple organic matrix, which was used as a template to synthesize particle size and morphology-controlling silver nanoparticles. The results of UV–vis determination and TEM observation indicated that uniform spherical silver nanoparticles with about 5 nm in size were obtained at the certain concentration of chitosan and silver ions. Hence, it is possible to control the size and morphology of silver nanoparticles at a certain extent by adjusting the concentration of chitosan and silver ions. In addition, triangle and hexagonal silver nanoparticles ranging from 20 nm to 60 nm in size appeared in different conditions. The advantage of this biomimetic synthesis of silver nanoparticles is that the process could be accomplished under mild conditions rather than stringent conditions, such as high temperature, very high pressures and a toxic environment, which usually occurs with the traditional methods for preparing metal nanoparticles.     

Assessment of cytotoxicity and immune compatibility of phytochemicals‐mediated biosynthesised silver nanoparticles using Cynara scolymus

The study was focused on the phytochemicals‐mediated biosynthesis of silver nanoparticles using leaf extracts and infusions from Cynara scolymus. To identify the antioxidant activity and total phenolic content, the 1,1‐diphenyl‐1‐picrylhydrazyl and Folin–Ciocalteau methods were applied, respectively. The formation and stability of the reduced silver ions were monitored by UV–vis spectrophotometer. The particle sizes of the silver nanoparticles were characterised using the dynamic light scattering technique and scanning electron microscope. The phase composition of the obtained silver nanoparticles was characterised by X‐ray diffraction. The silver nanoparticles suspension, artichoke infusion, and silver ions were separately tested towards potential cytotoxicity and pro‐inflammatory effect using mouse fibroblasts and human monocytes cell line, respectively. The total phenolic content and antioxidant activity of ethanol extract and infusion were found significantly higher as compared to aqueous extract and infusion. The UV–visible spectrophotometric analysis revealed the presence of the characteristic absorption band of the Ag nanoparticles. Moreover, it was found that with the increasing volume of plant extract, the average size of particles was increased. Biocompatibility results evidently showed that silver nanoparticles do not induce monocyte activation, however in order to avoid their cytotoxicity suspension at a concentration <2 ppm should be applied.Inspec keywords: pharmaceuticals, health and safety, renewable materials, toxicology, organic compounds, antibacterial activity, X‐ray diffraction, nanomedicine, nanoparticles, nanofabrication, suspensions, ultraviolet spectra, visible spectra, scanning electron microscopy, silver, particle sizeOther keywords: phytochemicals‐mediated biosynthesis, antioxidant activity, total phenolic content, dynamic light scattering technique, silver nanoparticles suspension, scanning electron microscopy, Cynara scolymus, 1,1 diphenyl‐1‐picrylhydrazyl method, cytotoxicity, immune compatibility, leaf extracts, UV‐vis spectrophotometry, particle size, Folin‐Ciocalteau methods, phase composition, X‐ray diffraction, artichoke infusion, pro‐inflammatory effect, mouse fibroblasts, human monocytes cell line, Ag     

Synthesis and Ag Recovery of Nanosized ZnO Powder by Solution Combustion Process for Photocatalytic Applications

Nanometer-sized ZnO powders for photocatalytic applications were prepared by a solution combustion method with various starting materials and fuels. It was easy to obtain single-phase ZnO powders using the solution combustion method regardless of the starting materials and fuels. However, the particle size and shape of the synthesized ZnO powders were different than the used fuel. Using glycine as a fuel, the particle shape of ZnO powders was spherical with uniform nanosize. On the other hand, using carbohydrazide as a fuel, the particle shape was platelike. The ZnO powder synthesized using Zn(OH)₂ and glycine as starting material and fuel, respectively, showed good powder characteristics, such as average grain size of 75 nm and the specific surface area of 94 m²/g. The average particle size and specific surface area were greatly dependent on the types of oxidants and fuels. Removal of silver ions from a used photo-film developing solution was attempted to examine the photocatalytic activity of the prepared ZnO powders. It also showed excellent photocatalytic properties in that the silver ions were completely removed from the solution within 3 min.     

天蓝黄链霉菌胞外合成纳米银的生化机制研究

以天蓝黄链霉菌（S. coelicoflavus）菌体浸出液为还原剂和包覆剂于胞外合成纳米银,对纳米银的形貌结构、晶体结构、粒度分布、元素组成及表面包覆基团进行表征分析,并通过研究主要生物活性分子在纳米银合成过程中的重要作用,探索了纳米银胞外合成的生化反应机制。表征分析结果表明,合成的纳米银颗粒主要为球形或近似球形,少量为截边三角形、四边形或六角形;平均粒径约为34.50 nm,呈中度多分散性;具有良好的结晶度和多晶结构。生化合成机制研究表明,蛋白质和还原型谷胱甘肽（GSH）在纳米银的合成过程中起主要作用;跨膜蛋白和细菌铁蛋白包覆于形成的纳米银颗粒表面,以保持其在反应体系中的高度稳定性;硝酸还原酶可能与其他生物活性组分共同催化银离子的还原过程。     

Optical properties of silver-doped aluminophosphate glasses

Silver-doped aluminophosphate glasses were prepared by the melt-quenching technique in which silver nanoparticles (NP) of different sizes were embedded upon heat treatment. Optical absorption and photoluminescence spectroscopy were used to study the optical properties of the material before and after thermal processing. Photoluminescence (PL) experiments revealed a broadband emission observed around 420 nm for the non-heat treated samples with a luminescence decay showing a bi-exponential behavior. Temperature dependence PL studies showed a thermal quenching effect on the broadband emission. Our data suggests that the emission is due to single Ag⁺ ions. Optical absorption measurements performed on the heat treated samples allowed for particle size estimation and the evaluation of the thermal stability of the glass system and its attributes as a host for NP inclusion. The nanocomposite showed a dip in the broadband emission of silver ions ascribed to absorption of Ag⁺ ions luminescence by surface plasmons in the silver particles.