核壳式无机-高分子纳米复合粒子的制备与表征

本文简要介绍了制备核壳式无机 -高分子纳米复合粒子的几种方法 ,着重概述了核壳式无机 -高分子纳米复合粒子的结构表征技术。     

核-壳型纳米复合材料研究进展

核壳型纳米复合材料由于独特性能而备受瞩目.综述了近年来核-壳型纳米复合材料的最新研究进展,特别是不同类型的核-壳型纳米复合材料的制备方法、应用前景.     

核壳型复合半导体纳米粒子的研究

核壳型复合半导体纳米粒子,作为复合半导体纳米粒子材料的一个重要分支,凭借其优异的性质,受到了广泛关注.本文主要介绍了有机/无机和无机/无机核壳型复合半导体纳米微粒及其光学性质、分类、制备方法和应用.并对其发展做了展望.     

空心核壳结构纳米粒子的制备研究进展及应用

本文对空心核壳结构纳米粒子的制备研究及应用进行了综述。     

核-壳结构纳米磁性复合颗粒的化学制备及应用进展

核-壳结构纳米磁性颗粒作为一种新型材料,具有广泛的应用前景,克服了磁性粒子易于团聚、化学稳定性不高、易受氧化、表面羟基不足等缺点。文中综述了Fe3O4/聚合物和Fe3O4/SiO2两大类核-壳结构的纳米磁性复合颗粒的化学制备方法,包括溶胶-凝胶法、硅烷化反应法、聚合法、自组装法、超声波法、高温合成法、凝结法、超临界流体...     

新方法制备Cu超细粉末以及Cu2O-Cu核-壳型复合粒子

以Cu(NO3)2·3H2O与Na2CO3·10H2O为原料沉淀法制得纳米CuO前驱体--碱式碳酸铜,在不同温度(200℃、300℃、400℃、500℃、600℃)下分别焙烧2h得到CuO粉末后,直接倒入室温下的正丁醇溶液中,发生氧化-还原反应,得到组成不同的各种产物.经XRD、TEM、SEM研究表明,产物的组成随上述热处理温度的改变而变化,500℃时可得到纯的纳米铜粉,600℃时可得到Cu2O-Cu核-壳型纳米粒子.     

功能型核壳有机-有机纳米复合粒子的研究进展

核壳型有机-有机纳米复合粒子由于具有粒子可控设计,有机融合不同组分优势等特性,已在导电高分子、水凝胶、舍氟乳液和塑溶胶等方面获得应用.综述了近年来(甲基)丙烯酸酯类不同功能的核壳型有机-有机纳米复合粒子的研究进展,揭示了功能型核壳有机-有机纳米复合粒子在某些领域的巨大应用潜力和存在的问题.     

核壳结构型纳米CaCO3-SiO2.nH2O复合粒子的制备

在搅拌槽式反应器中,以用超重力法合成的纳米 ＣａＣＯ３和 Ｎａ２ＳｉＯ３为原料,用溶胶－凝胶技术制备具有核壳结构的纳米 ＣａＣＯ３－ＳｉＯ２·ｎＨ２Ｏ复合粒子　用 ＸＰＳ、 ＴＥＭ、 ＸＲＤ等方法对粒子的化学组成、形貌、晶型等作了分析和表征     

SiO2／Ag核壳复合粒子的制备与表征

首次引入活性SiO2微球作为核基，采用自组装液相还原技术，定向的在核基上沉积纳米银颗粒得到SiO2／Ag核壳复合粒子；并用红外、x射线衍射、场发射扫描电镜、能谱等分析表征该核壳复合粒子的形貌与结构。结果表明：利用活性SiO2作为核基，pH值为12．4，有表面活性剂参与的条件下，通过改变银前驱体浓度，可实现表面包覆致密、银壳厚度可控的核壳复合粒子化学制备技术。     

纳米Ti/PAM复合粒子的制备?

利用 KH-560硅烷对纳米钛粉进行偶联处理,以十二烷基苯磺酸钠(SDBS)作为分散剂,通过原位聚合方法制备了纳米钛/聚丙烯酰胺(纳米 Ti/PAM)复合粒子。运用 XPS、TEM、FT-IR 等测试手段对粉体材料进行表征,研究了偶联处理和原位聚合包覆对纳米钛粉在 M03环氧树脂稀释液中分散能力的影响。结果表明,核壳结构的纳米 Ti/PAM复合粒子粉体颗粒间不易团聚,将其分散在M03环氧树脂稀释液中之后混合液出现可目视观察的初始沉淀在20 h以上,且混合液中固体颗粒的分散状态较为稳定。     

Impact ignition of nano and micron composite energetic materials

Nanoscale reactive materials demonstrate three orders of magnitude reduced laser ignition sensitivity compared to their micron scale counterparts. Reduced ignition delay times have been reported for a variety of nano composites including aluminum combined with another metal (e.g., Ni), metallic oxides (e.g., MoO₃, Fe₂O₃, CuO, WO₃), or polymer binders such as polytetrafloroethylene (Teflon™). A new reported melt dispersion mechanism associated with nano-aluminum particle ignition explains the enhanced thermal ignition sensitivity associated with nano-aluminum composites. As a comparison to laser thermal ignition behaviors, this study focuses on impact induced ignition of nano- and micron-aluminum particle composites that also include Ni, MoO₃, or Teflon. A modified type-12 impact tester is used to measure ignition of the energetic composites to drop weight impact. Ignition is determined using high-speed thermal imaging. To assess the influence of the alumina passivation shell on the ignition dynamics, oxide-free nano-aluminum passivated with a perfluoroalkyl carboxylate self-assembled monolayer has also been investigated. Results show that the difference in ignition sensitivity between nano and micron composites is significantly greater with laser than with mechanical ignition and the melt dispersion mechanism does not describe impact ignition.     

环氧树脂／纳米TiO2复合材料的制备与性能研究

以纳米TiO2和聚苯胺包覆纳米TiO2后的颗粒作为增强组分，通过溶液共混法制备环氧树脂基纳米复合材料。IR结果表明，纳米TiO2颗粒表面舜口聚苯胺之间存在强烈的相互作用：这种包覆后的纳米粒子作为填料，能提高其与基体环氧树脂的界面相容性，使其能均匀地分散在环氧树脂基体中，在添加量为3％（质量分数，下同）时，拉伸强度比纯的环氧树脂提高了39．3％。     

Preparation of amorphous composite materials

Composite meterialoconuioting of an amorphous Ni₇₅B₁₇Si₈ matrix and containing one or two reinforcing tungsten wire(s) were prepared by a modified melt-spinning technique, With this method it was possible to incorporate a single 10, 26 and 60m wire in the entire length of an amorphous ribbon, as well as two 26m wires. The process is continuous and allows the praparation of arbitrarily long composite ribbons.     

Preparation and properties of close-packed composite materials

Monodisperse silica particles of about 0.3m diameter are suspended in methacrylate monomer using a carefully selected dispersant. Many steric dispersants are hydrocarbon chains with a reactive end-group. These are not effective as dispersants for silica in moderately polar solvents, such as esters and the methacrylate monomers. Good dispersion was obtained with a methacrylate polymer terminated by a chlorosilane end group. Settling or centrifugation of these unagglomerated dispersions gives well-packed particle beds. Polymerization of the surrounding monomer produces composite materials with high packing fractions and a high degree of regularity. Moduli and strengths of these composites are reported.     

An implicit finite element material model for energetic particulate composite materials

The predisposition of energetic particulate composite materials, or high explosives (HE), to ignition by bulk heating (cookoff) poses serious safety problems. Because unexpected initiation of HE must be a major consideration in any activity involving employment of the material, its behaviour under a variety of conditions is of much interest. The formulation of a numerical constitutive model that can be employed in an implicit finite element code to predict the mechanical and ignition behaviour of HE is presented. The capability of the developed material model is then demonstrated through its implementation in the ABAQUS finite element code to simulate the response of HE test configurations. The simulated response is found to compare favourably with the physical test results, in the cases where test data exist. Copyright © 2000 John Wiley & Sons, Ltd.     

Preparation of nano-sized graphite-supported CuO and Cu-Sn as active materials in lithium ion batteries

Nano-sized Cu-Sn and Cu oxide particles supported on ball-milled graphite were synthesized, and their electrochemical characteristics for use as anode active materials in lithium-ion batteries were investigated. The samples were also characterized via FE-SEM, XRD, and TGA. Most of the Cu oxides on BMG were monoclinic CuO crystals, whereas the Cu-Sn particles were composed of hexagonal Cu3Sn and tetragonal SnO2 crystals. These particles may contribute to an increase in the reversible capacity of lithium ion batteries.     

颅骨修复复合材料的制备

主要论述了碳纤维 (CF)和玻璃纤维 (GF)混杂增强聚甲基丙烯酸甲酯 (PMMA) /羟基磷灰石 (HA)复合材料人工颅骨的制备方法及其力学性能。通过实验 ,证实了此复合材料具有比单纯GF增强PMMA/HA复合材料人工颅骨更好的物理机械性能 ,是目前制作人工颅骨较为理想的材料。     

Electro-analysis of energetic materials

Cyclic voltammetric studies of triaminoguanidine nitrate (TAGN), 3,3'-hydrazino bis(bis[6,6'-(3,5-dimethylpyrazol-lyl])-1,2,4,5-tetrazine (HBPT), 4,6-dinitrobenzofuroxan (DNBF) and 3,3'-diamino-4,4'-azoxyfurazan (DAAF) were carried out at different pH conditions in 50% aqueous acetonitrile using glassy carbon electrode. Optimum pH was selected for individual compounds. Influence of scan rate and concentration on the voltammetric response were studied in optimum pH. The number of electron transferred was determined by controlled potential coulometry. All compounds undergo diffusion controlled electrochemical reaction. Based on cyclic voltammetric results, differential pulse and square wave voltammetric methods have been developed for the analytical determination. Instrumental parameters such as initial scan potential, amplitude, pulse increment, pulse period, pulse width and frequency were studied. Optimum experimental conditions for each compound were obtained. After fixing optimum conditions, the effect of concentration was studied and calibration plot was arrived. These plots can be used to determine the traces of the above said four energetic materials.