超声技术在纳米材料制备中的应用

对超声技术在纳米材料制备中的应用与研究进展作了比较全面的综述,着重介绍了与超声有关的纳米材料制备方法,包括雪声雾化－热分解法,金属有机物超声热分解法,化学沉淀法和声电化学法,并就这些方法中声化作用的机理,特点和影响因素进行了讨论。     

超声化学在纳米材料制备中的应用

纳米材料的稳定性、物理化学性能及粒子的大小与制备方法密切相关.近年来,超声技术已被用于纳米材料的制备,并初步显示了其优越性.本文介绍了超声沉淀法、超声热解法、超声还原法、超声电化学法、超声体相扩散法等制备纳米材料方法的进展,对这些方法有关的作用机理、影响纳米产物的因素、各种方法具备的优势进行了讨论.     

纳米材料的概述、制备及其结构表征

纳米材料在电子、光学、化工、陶瓷、生物和医药等诸多方面的重要应用而引起人们的高度重视。本文从以下3个方面加以论述。 一、纳米材料的概述:从分子识别、分子自组装、吸附分子与基底的相互关系、分子操作与分子器件的构筑,并通过具体的例证加以阐述,包括在STM操作下单分子反应;有机小分子在半导体表面的自指导生长;多肽-半导体表面特异性选择结合;生物分子/无机纳米组装体;光驱动多组分三维结构组装体;DNA分子机器。 二、纳米材料的若干制备方法和结构表征方法:制备方法包括:物理的蒸发冷凝法,分子束外延法(MBE),机械球磨法,扫描探针显微镜法(SPM)。化学的气相沉淀法(VCD),液相沉淀法,溶胶-凝胶法(Sol-gel),L-B膜法,自组装单分子层和表面图案化法,水热/溶剂热法,喷雾热解法,样板合成法或化学环境限制法及自组装法。 三、若干结构表征方法包括:X-射线法(XRD),扩展X射线精细结构吸收谱(EXAFS),X-射线光电子能谱(XPS),光谱法,扫描隧道显微镜/原子力显微镜(STM/AFM)和有机质谱法(OMS)。     

纳米合金的制备进展*

对纳米合金材料的制备方法和研究进展作了比较全面的综述.对机械合金化法(BM)、还原法、超声波法、脉冲电沉积法、静高压法、激光汽化器控制浓度法(LVCC)、氢等离子体-金属反应法、非晶晶化法等进行了介绍,并对这些方法有关的机理、特点、影响因素以及结果等进行了讨论.     

PTCR纳米陶瓷粉及其烧结体的制备

The PTCR(positive temperature coefficient of resistance) nanosized ceramic powder was prepared by Sol-Gel process and characterized by XRD, DSC, SEM and BET techniques. The results showed that the nanopowder has an average crystallite size of 35nm with sphere-shaped, whose specific surface area is 27.80m²·g^-1 and the crystal structure is abnormal cubical perovskite phase at room temperature. In addition, the nanopowder was pressed into pellets and then sintered according to improved technique which was built based on the data of thermal analysis of the PTCR green-compact to yield PTCR ceramic materials with peculiar microstructure and higher properties, which has a resistivity at room temperature of ～20Ω·cm, a temperature coefficient of resistivity of ～19%·℃^-1, a withstand voltage intensity of >160V·mm^-1 and a resistivity jump of >10⁵.     

Nanosized Additives to Lubricating Materials

The review deals with the synthesis and use of nanosized additives in friction and wear processes. Various types of nanosized additives are considered, and their performance as friction modifiers is demonstrated. The influence exerted on the antiwear performance of lubricating materials by the size and concentration of the introduced particles differing in the chemical nature is considered. Methods for preparing nanosized additives and stabilizing them in lubricating materials are described.     

Advanced Materials Based on Nanosized Hydroxyapatite

The development of new materials based on hydroxyapatite has undergone a great evolution in recent decades due to technological advances and development of computational techniques. The focus of this review is the various attempts to improve new hydroxyapatite-based materials. First, we comment on the most used processing routes, highlighting their advantages and disadvantages. We will now focus on other routes, less common due to their specificity and/or recent development. We also include a block dedicated to the impact of computational techniques in the development of these new systems, including: QSAR, DFT, Finite Elements of Machine Learning. In the following part we focus on the most innovative applications of these materials, ranging from medicine to new disciplines such as catalysis, environment, filtration, or energy. The review concludes with an outlook for possible new research directions.     

Preparation,Characterization and Applications of Electron-Beam Curing-Derived Monolithic Materials

Summary: Acrylate/methacrylate-based monoliths have been prepared via electron- beam (EB) initiated polymerization. These monolithic columns were found suitable for application in the analytical scale separation of various analytes such as proteins. Functionalization of the monolithic columns was accomplished via copolymerization of functional monomers. Selected examples of both synthesis and application will be summarized.     

Preparation of MMA－BA－DMAEMA Nanosized Latex

The terpolymer latex of methyl methacrylate (MMA)/butyl acrylate (BA)/ dimethyl aminoethyl methacrylate (DMAEMA) with diameter of less than 100 nm was prepared by seeding semi-continuous emulsion copolymerization using APS (ammonium pcrsulfate) / TMEDA (N,N,N,N-tetramethylethylenediamine) as the redox initiators and SDS (sodium dodecylsulfate) and OP (P-octylpolyethylene glycol phenylether) as co-emulsifiers. The factors that influenced the process stability of the copolymerization and the particle size of the latex were investigated. The addition of aqueous ammonia as coagulation inhibitor provided better process stability of the copoly- merization. The addition of acetic acid as the acidification agent caused a remarkable reduction of the latex particle size.     

基于分子印迹技术的吸附材料制备与应用进展

在简要介绍超分子理论的基础上,综述了分子印迹微球和分子印迹膜的制备方法,介绍了其在吸附金属、吸附脱硫、吸附有机小分子以及吸附蛋白质等方面的应用进展。     

酰肼类化合物的羰基化制备及其在智能材料合成中的应用

酰肼类化合物在农药、医药等领域被广泛应用,其合成方法的研究备受关注.卤代物和有机肼(或单酰肼)的羰基化反应是制备酰肼类化合物的重要合成路线之一.在由羰基化反应制备酰肼类化合物的过程中,除以CO气体作为典型、廉价易得的羰基源外,CO2、DMC(碳酸二甲酯)、固体羰基配合物等都可以作为替代CO气体的潜在羰基源.我们着重介绍...     

样品前处理介质的制备与应用研究进展

样品分析是环境污染物研究和控制的基础,到目前为止,环境样品前处理仍是环境样品分析的瓶颈问题,其中,针对复杂环境基质中的痕量污染物开发高效率和高选择性的吸附材料是样品前处理的关键和研究热点。微孔有机聚合物、有序介孔硅材料、金属有机骨架聚合物、分子印迹聚合物、碳纳米管和石墨烯等新材料具有骨架密度低、比表面积大、孔尺寸可调控、表面可修饰、化学和物理性质稳定等优点,在样品前处理领域展现出巨大的应用潜力。该文对近年来这些新型纳米材料在固相萃取、分散固相萃取、固相微萃取、磁固相萃取、搅拌棒吸附萃取和基质固相分散萃取等样品前处理领域的最新研究进展做了简要评述,为更好地开发新型纳米材料在复杂和痕量样品前处理中的应用提供了参考。     

Chemically Treated Carbon Nanofiber Materials for Supercapacitors

Doklady Chemistry - Carbon nanofibers obtained by catalytic decomposition of methane in a vibrated fluidized bed reactor were chemically treated to increase the specific capacitance of...     

Hierarchically Porous Organic Materials Derived From Copolymers: Preparation and Electrochemical Applications

Abstract

Compared to conventional porous materials with a uniform pore size distribution, hierarchical ones containing interconnected macro-, meso-, and micropores have greatly enhanced material performance due to the increased specific surface area and mass transfer. Copolymer is a good candidate used for construction of such hierarchically porous structures, resulting from its tunable segment composition, unique phase separation, and self-assembly, etc. Hierarchically porous materials derived from copolymers can be served as a versatile support for many reactive molecules. Furthermore, hierarchically porous carbon materials (HPCMs) can also be prepared by carbonization of copolymers, one segment of which is converted to carbon while the other segment is responsible for the pore formation after its removal by pyrolysis. The obtained hierarchically porous copolymers or carbon materials have promising electrochemical applications especially in energy conversion and storage. In the present review, recent advances in preparation of hierarchically porous materials (HPMs) derived from copolymers are reviewed, and their electrochemical applications in supercapacitors, lithium-ion batteries, fuel cells, electrochemical biosensors, and electrocatalysis are also introduced. The rational design and control for the hierarchically porous microstructures are described deeply from the molecular level. Also, the relationship between the micro-structure and the electrochemical performance is revealed. This review can provide us a better understanding of both theory and experiment for the preparation of hierarchically porous organic materials and their electrochemical applications.     

有机或金属-有机二维纳米材料的制备与应用

对石墨烯等二维材料的研究进一步引发了人们对相似结构的其他有机、金属-有机二维层状纳米材料的浓厚兴趣. 这些二维材料由于其优异的化学可剪裁性而受到关注, 预期未来在电子器件、催化和小分子分离等方面具有广泛的用途. 这篇综述系统地介绍了目前制备有机基二维材料的自上而下和自下而上的两大类方法, 总结了有机基二维材料在生物识别、小分子分离和纯化以及电学方面的应用, 最后讨论了有机基二维材料目前在制备和性质改进方面面临的问题和未来可能发展的研究方向.     

稀土铽超分子纳米功能材料的荧光性质比较

稀土配合物Tb(Phen)x(Bipy)(4-x)(NO3)3(x=4,3,2,1,0)(1×10-3mol·L)溶液中,当配体邻菲罗琳(Phen)和2,2′ 联吡啶(Bipy)共存同一铽的配合物中时,Tb3+的特征发光被敏化,其中Tb(Phen)3(Bipy)(NO3)3的荧光强度是最强,Tb(Bipy)4(NO3)3的荧光强度是最弱。Tb3+在(CH3)3Si MCM 41 Tb(Bipy)4(NO3)3中的特征发光强度最强,而在MCM 41 Tb(Phen)3(Bipy)(NO3)3和(CH3)3Si MCM 41 Tb(Phen)3(Bipy)(NO3)3中的发光变得很弱。当客体分子Tb(Phen)4(NO3)3和Tb(Bipy)4(NO3)3被组装到疏水的主体分子筛(CH3)3Si MCM 41孔道里要比组装到亲水的分子筛MCM 41孔道里的发光要强;当客体分子是Tb(Phen)3(Bipy)(NO3)3和Tb(Phen)2(Bipy)2(NO3)3时,它们的发光情况与前一种情况刚好相反即亲水的极性内腔环境有利于客体分子的发光;平行的荧光寿命试验的结论也是一致的。说明在不同的超分子体系中,疏水和亲水的环境都有可能利于客体分子的发光。在(CH3)3Si MCM 41 Tb(Phen)(Bipy)3(NO3)3中的配体的荧光强度要比在MCM 41 Tb(Phen)(Bipy)3(NO3)3中的强;而Tb3+的特征荧光强度的情况刚好相反。MCM 41 Tb(Phen)(Bipy)3(NO3)3和(CH3)3Si MCM 41 Tb(Phen)(Bipy)3(NO3)3有明显的双指数衰减,双指数衰减拟合所得荧光寿命分别为168.8,641.1μs和73.2,5     

基于硅材料的分子印迹聚合物的制备及应用*

分子印迹聚合物因制备简单、稳定性好、且具有分子识别功能使其在色谱分离、固相萃取、化学传感、模拟酶催化等方面有了广泛的应用。近年来,基于硅的分子印迹聚合物发展较为快速。本文主要介绍了以硅为母体材料和以硅为基质材料的分子印迹聚合物的制备及分子识别性质研究,并对其应用进行了分类,在此基础上对其将来的发展进行了展望。     

有机物单层分散在相关材料制备中的应用

与无机氧化物和盐类在载体表面自发单层分散相类似, 许多有机物也可以在载体表面自发单层分散.有机物在载体表面单层分散行为和分散后的存在状态与有机物分子形状和结构特点及载体表面性质和孔结构有关. 利用有机物在载体表面的单层分散, 可以设计制备具有优异性能的材料. 本文简要综述了近年来这方面研究工作取得的相关进展, 主要介绍了有机物单层分散在碳/氧化物复合物、氧化物和薄壁中孔碳材料的制备和织构调控方面的一些应用实例. 单层分散的有机物热分解后可在载体表面形成均匀的薄碳层, 以无机多孔氧化物为载体可制备出包覆均匀碳薄层的碳/氧化物复合物, 这种碳/氧化物复合物在染料吸附、催化剂载体和光催化方面显现出好的性能. 以溶胶-凝胶法制备氧化物时, 分散的有机物可以隔离溶胶颗粒, 从而制备出高比表面积的氧化物并可对孔容进行调控, 以此方法制备的γ-氧化铝比表面积可达506 m²·g^-1. 在惰性气氛中加热上述碳/氧化物复合物, 碳层可抑制氧化物的相变; 而在氧气中, 碳层燃烧发热会促进相变, 由此可快速制备超细α-氧化铝. 包覆均匀碳薄层的氧化物载体对碳起支撑作用, 在将氧化物溶解去除后, 可便捷制得高比表面积、大孔容、高中孔率的薄壁中孔碳材料, 碳材料的形貌、孔径分布等可通过选用不同织构的氧化物载体进行调控.     

铜电极上Zn—Co—P合金电沉积行为

铜电极上Ｚｎ┐Ｃｏ┐Ｐ合金电沉积行为黄清安＊陈永言邓伯华（武汉大学化学系武汉４３００７２）关键词铜电极，Ｚｎ－Ｃｏ－Ｐ合金，电沉积１９９６－０４－２３收稿，１９９６－０９－１３修回国家自然科学基金资助课题为了提高Ｚｎ层的耐蚀性，出现了含磷的锌基合金，...     

乳状液法制备ZnS纳米粒子

乳状液法制备ＺｎＳ纳米粒子黄宵滨马季铭＊程虎民赵振国齐利民（北京大学化学系北京１００８７１）关键词硫化锌，纳米粒子，乳状液，混合乳化剂１９９６－０５－２０收稿，１９９６－０９－０４修回国家自然科学基金资助项目近年来，利用反胶束或Ｗ／Ｏ微乳制备超细粒子...