纳米结构组装体系的制备和应用

纳米结构的自组装体系的出现,标志着纳米材料科学研究进入了一个新的阶段。将纳米结构单元组装成二维(2D)或三维(3D)的纳米颗粒的有序阵列,对纳米器件的构筑具有重要的意义。利用自组装技术,合成具有有序结构的纳米颗粒阵列结构或复合结构是科学家们研究的热点。本文介绍了自组装的方法,综述了自组装技术在纳米技术发展中的应用以及研究现状。     

金属纳米粒子组装阵列的UV光谱研究

以3-巯基丙基三甲氧基硅烷和对巯基苯为偶联分子．在玻璃基底上进行了二维和三维金、银纳米粒子的组装．以扫描电镜表征并研究其紫外吸收光谱．结果表明,随着组装层数的增加．紫外峰位发生红移,说明层与层之间存在耦合效应。     

铂纳米颗粒自组装膜的微图像化

从硝基重氮树脂(NDR)与包裹巯基乙酸的铂纳米颗粒(MA-PtNP)的静电自组装，制备了感光性的自组装多层超薄膜，经选择性紫外曝光和十二烷基硫酸钠(SDS)水溶液显影，光照部分的膜，因层与层之间的离子键转变为共价键，不再被SDS水溶液洗脱而留下来；未光照部分的膜，层与层之间仍是离子键，在显影时被除去，从而形成图像、用AFM和SEM对形成的图像进行了表征．     

纳米金自组装多层膜电极制备及电催化研究

用自组装法将纳米金粒子组装到化学修饰过的ITO玻璃片上,制备了一种新型的多层纳米金修饰电极。用紫外可见光谱、循环伏安等方法对其进行了研究。结果表明：电极对抗坏血酸具有良好的电催化氧化作用,峰电流与浓度在1．0×10^-5～1．4×10^-2mol／L范围内线性关系良好,检出限4．0×10^-6mol／L。     

光致变色的PWl2／1，10-DAD自组装超晶格多层膜

本文报道了在固体基底表面上用PE方法连续自组装沉积PWl2和1,10-DAD分子,构建了PWl2／1,10-DAD自组装多层膜．紫外一可见吸收、X射线衍射等分析结果表明此多层膜有好的超晶格结构,层间距为3．19nm．与真空蒸镀WO3薄膜相比,PWl2／1,10-DAD自组装多层膜表现出更好的光致变色特性．     

具有诊疗效果的新型载体材料及其应用

超薄膜类生物活性材料是近年来兴起的一种新型材料,具有功能结构多样、来源丰富、高生物兼容性等优点。超薄膜类生物活性材料超分子自组装体是以分子间的非共价相互作用为主导,进而形成的分子聚集体,在自组装的组成过程中,其基元物质是分子、聚合物、胶体以及宏观的颗粒物质,在非人为干预下自发地变为有序的功能性结构体。本文综述了不同组装基元,通过超分子非共价作用力,构建的具有诊疗效果的新型载体材料。重点介绍了中空微胶囊和多层核壳结构纳米材料在光疗、化疗以及联合治疗中的应用,展现了超薄膜组装得到的新型载体材料在生物医药领域潜在的应用。     

导电纳米颗粒对Sb:SnO2薄膜性能影响研究

采用水热晶化法,通过控制水热反应条件、溶液的浓度以及矿化剂的种类等因素,制备出分散性及导电性良好的SnO2纳米颗粒.采用溶胶-凝胶浸渍镀膜的方法制备Sb掺杂SnO2薄膜,在镀膜溶液的配制过程中引入SnO2纳米颗粒悬浮液,经陈化后最终得到镀膜溶液.采用van der Pauw法、UV/VIS分光光度计以及Fourier变换红外光谱仪研究和分析了添加纳米颗粒对膜层导电性能、光学性能以及膜层结构的影响;采用场发射扫描电镜研究了膜层的表面形貌.结果表明导电纳米颗粒的加入可有效提高膜层的导电性能,当SnO2纳米颗粒添加质量分数为10%时,膜层的电阻率为6.5×10…3Ω·cm;添加和未添加纳米颗粒的膜层的可见光透过率均为85%.纳米颗粒参与了溶胶-凝胶制备薄膜网络的形成,提高了膜层结构的连续性,从而使膜层具有较好的导电性能和光学性能.     

多孔纳米碳纤维作为质子交换膜燃料电池微孔层的性能

质子交换膜燃料电池膜电极中的微孔层结构对改善体系的水管理能力，提升膜电极的整体性能发挥重要作用。本文通过静电纺丝和后续热处理的方法制备了多孔纳米碳纤维（PCNF），并以此构建膜电极的微孔层。与炭黑颗粒作为微孔层呈现出紧密堆积结构不同，由PCNF搭建的微孔层结构疏松呈现三维贯通状。膜电极的发电测试表明，以多孔纳米碳纤维作为微孔层（MPL-PCNF）的膜电极其最大功率密度达70.0mW/cm²，远高于炭黑颗粒为微孔层（MPL-CB）的膜电极（58.1mW/cm²），而没有微孔层（Ref）结构的膜电极最大功率密度仅为27.7mW/cm²，显示出PCNF作为微孔层材料的明显优势。     

二层组装四磺酸酞菁铜修饰电极的制备、表征与应用

四磺酸酞菁铜在1，3-二环己基碳二亚胺（DCC）的活化下与自组装膜上的氨基发生表面化学反应，制得了二层组装半胱胺．四磺酸酞菁铜／金电极，将四磺酸酞菁铜固定在金电极表面。利用循环伏安、扫描电镜进行了组装电极的表征。这种二层组装的电极对半胱胺酸具有催化作用。     

基于双巯基化合物和纳米金固定生物分子的研究

利用自组装方法，将双巯基化合物通过形成金硫键修饰至金电极表面，再利用双巯基化合物的另一个一SH基，吸附纳米金颗粒形成纳米金的膜。运用循环伏安法对此修饰电极进行研究。发现双巯基化合物的最佳修饰时间为2小时；纳米金的最佳修饰速度为6小时：当扫描速度为100mv／s时固定抗体抗原的效果最好；而抗体抗原浓度为1：4时固定效果最佳；     

Synthesis of ordered mesoporous carbon films, powders, and fibers by direct triblock-copolymer-templating method using an ethanol/water system

Morphology control of ordered mesoporous carbon was performed using an organic-organic interaction approach. Mesoporous carbons were synthesized from a resorcinol-phloroglucinol/formaldehyde polymer and triblock copolymer Pluronic F127 in ethanol-water solutions of different molar ratios. A face-centered orthorhombic Fmmm structure was formed in the film prepared by dip-coating method. A three-dimensional wormhole-like mesostructure was formed during powder preparation at EtOH/water molar ratios ranging from 0.5 to 1.25. When the molar ratio was further increased to 2.5, a hexagonal p6mm structure was obtained. The pore size of the mesoporous carbon powders increases with increasing EtOH/water molar ratio. A dual-templating approach was demonstrated to prepare mesoporous carbon nanofibers. Anodic aluminum oxide membranes were used as a hard template. A mesostructure with a short-range order was formed and oriented along the surface in different directions. The structural order became distorted in the interior region.     

钙钛矿复合氧化物的介孔化及用于CH4催化燃烧

利用有序介孔立方相(Ia3d)乙烯基三乙氧基硅烷(TEVS)为模扳,通过纳米组装法在硅基硬模板的介孔中填入La - Fe -柠檬酸络合物,经焙烧和碱洗去除硅基模板,制备具有有序介孔结构且高比表面积的LaFeO3钙钛矿(ABO3),并与软模板法和自燃烧法制备的LaFeO3钙钛矿催化荆作对比,运用XRD、TEM和BET对合...     

Effect of the film thickness on the fabrication of ordered TiO2 thin film microstructures by transfer printing

This paper describes a transfer printing technique for directly patterning ordered TiO₂ thin films onto Si substrates. Two- or three-dimensional TiO₂ structures can be fabricated onto an Si substrate depending on the coating film thickness, which is controlled via the liquid phase deposition process parameters and attractive interaction forces between a poly(dimethylsiloxane) stamp and a polyelectrolyte layer during the transfer printing process. This additive transfer process is mediated by the presence of a thiol (SH)-terminated 3-mercaptopropyltrimethoxysilane self-assembled monolayer on the wafer surface. The transferred patterns are chemically bonded to the wafer surface, exhibiting strong adhesion. The attractive interaction forces between the stamp and the polyelectrolyte layer was weak enough to allow ready detachment of the patterns from the stamp during printing. Even the parts of a continuous TiO₂ film that are not in contact with the substrate effectively transfer to form a free-standing structure. With long and short deposition times, three-dimensional structures and ordered two-dimensional round-hole grid structures, respectively, are obtained after the removal of the stamps.     

Boundary layer chemical vapor synthesis of self-organized radial filled-carbon-nanotube structures

We report a new chemical vapor synthesis method that exploits random fluctuations in the viscous boundary layer between a laminar vapor flow and a surface to yield a not previously observed product: radial ferromagnetically filled-carbon-nanotube structures departing from a central particle. The filling of the nanotube capillary is continuous over a scale much greater than that which can be achieved by conventional CVD. This is a simple method which does not require ultra-fine control of process parameters or highly-engineered reactor components in which a single, self-organized, ordered product is formed in randomly fluctuating vapor in the boundary layer by vapor-, liquid-, solid-phase self-organization. These fluctuations create the thermodynamic conditions for formation of the central particle in the vapor which in turn defines the spherically symmetric diffusion gradient that initiates the radial growth. The subsequent radial growth is driven by the supply of vapor feedstock by local diffusion gradients created by endothermic graphitic carbon formation at the vapor-facing tips of the individual nanotubes and is halted by contact with the surface. The radial structures are the dominant product and the reaction conditions are self-sustaining. We argue that the method has potential for scalable production of metal-carbon nanostructures with other unusual morphologies.     

聚苯乙烯胶体晶体模板制备及在3DOM-SiO_2材料制备中应用

通过创新的方法制备聚苯乙烯（PS）胶体晶体,成功的制备出粒径在255nm左右的PS胶体晶体,并阐述了乳化剂用量对PS胶体晶体有序性排列的影响。用此PS胶体晶体为模板制备3DOM-SiO2材料,通过扫描电镜与透射电镜观察,SiO2大孔材料的孔径收缩率为10%左右,并且大孔SiO2在大面积范围内排列整齐有序,孔壁均匀致密光滑,是典型的三维有序大孔结构,3DOM-SiO2材料整体上呈面心立方体结构。     

基于CMS实测的采空区群稳定性数值模拟方法

应用空区探测系统(Cavity Monitoring System,简称CMS),精确地获取地下矿山采空区的三维形态和准确的空间位置,并借助大型三维矿床软件SURPAC建立起了空区的三维形态模型,在此基础上,研究提出了空区稳定性数值模拟建模的SURPAC和FLAC3D耦合方式,形成了基于实测的采空区稳定性数值模拟分析的新方法,有效地提高了采空区稳定性数值模拟结果的准确性和可靠性.该方法已在铜坑矿采空区群稳定性数值模拟研究中成功应用,验证了该技术的有效性和可靠性.     

Vitreous carbon micro-lattice structures

A new approach is presented to fabricate open-cellular carbon materials with an ordered, lattice-type micro-scale architecture. The carbon micro-lattice materials were fabricated by pyrolyzing a polymer precursor template formed from an interconnected three-dimensional array of self-propagating photopolymer waveguides. Impregnating the polymer precursor template with acrylonitrile increased the carbon yield of the material from 19% to 46%. Structural analysis and density measurements of the solid carbon phase are consistent with vitreous carbon. Compression experiments yielded a compressive modulus (E) of 1.1 GPa and a failure strength (σ_f) of 10.2 MPa for a structure with relative density of 12.8%.     

冰水界面动态结构的分子动力学模拟研究

为了探究结冰过程冰水界面结构的动态复杂性,利用分子动力学模拟方法构建微观的冰水两相共存模型,研究了冰水两相界面结构随温度和晶面的变化规律。结果表明,当冰水两相达到平衡时,冰水界面结构中存在无序水分子和有序冰晶结构的可逆动态转变,造成了界面结构的不均匀性。在改变环境温度和晶面类型时,冰水界面结构表现出不同的分布规律。在相同的温度下,一次棱柱面和二次棱柱面的界面层厚度比基面的略薄,而棱柱面水分子排列的有序性强,且存在分子间氢键的三维网络重组。当过冷度较大时,界面结构趋于六元环排列的有序状态,界面内无序水分子增多,同时水分子在界面层内的停留时间增长。从分子尺度上阐明了冰水体系界面结构的变化规律,对理解结冰过程和发展控冰技术具有一定的指导意义。     

Self-assembly of micelles into designed networks

The EO₂₀PO₇₀EO₂₀ (molecular weight 5800) amphiphile as a template is to form dispersed micelle structures. Silver nanoparticles, as inorganic precursors synthesized by a laser ablation method in pure water, are able to produce the highly ordered vesicles detected by TEM micrography. The thickness of the outer layer of a micelle, formed by the silver nanoparticles interacting preferentially with the more hydrophilic EO₂₀ block, was around 3.5 nm. The vesicular structure ensembled from micelles is due to proceeding to the mixture of cubic and hexagonal phases.