STUDY ON A HYDROPHOBIC-HYDROPHILIC GRADIENT ROD

INTRODUCTIONGradient materials constitute a special case of various materials. The concentration of one of the components ofthe material, being chemically and/or physically different from other components, is allowed to change as afunction of its position in the sample, producing a predetermined gradient profile. The gradient material can be inany shape — i.e., linear, sigmoid, parabolic, flat or rod. Generally, this kind of material should have gradientsalong one direction in their stru…     

超高分子量聚乙烯纤维表面改性的研究进展

超高分子量聚乙烯(UHMWPE)纤维具有诸多优异性能,因此被广泛应用于纤维增强复合材料(FRP)。但是由于UHMWPE纤维表面光滑且无极性基团,与树脂基体粘接性差,可通过纤维表面改性有效提高FRP的界面强度,进而提升材料性能。本文总结了近几年基于化学处理、等离子体处理、电晕放电和辐射引发表面接枝等方法对UHMWPE纤维表面改性的研究进展,并对改性方法的发展进行了展望。     

Effects of ultra-high temperature treatment on the microstructure of carbon fibers

The microcrystalline structure and microvoid structure in carbon fibers during graphitization process(2300-2700 °C) were characterized employing laser micro-Raman scattering(Raman), X-ray diffraction(XRD), small angle X-ray scattering(SAXS), and high-resolution transmission electron microscopy(HR-TEM). The crystalline sizes(L_a, L_c) increased and interlayer spacing(d_(002)) decreased with increasing heat treatment temperature(HTT). The microvoids in the fibers grew up and contacted to the neighbors with the development of microcrystalline. In addition, the preferred orientation of graphite crystallite along fiber axis decreased and microvoids increased. The results are crucial for analyzing the evolution of microstructure of carbon fibers in the process of heat treatment and important for the preparation of high strength and high modulus carbon fibers.     

超疏水表面的研究进展

表面的浸润性是决定材料应用的一个重要性质,许多物理化学过程,如吸附、润滑、黏合、分散和摩擦等均与表面的浸润性密切相关.近年来,由于超疏水表面在自清洁表面、微流体系统和生物相容性等方面的潜在应用,有关超疏水表面的研究引起了极大的关注.本文综述了超疏水表面研究的新进展:简单介绍了表面浸润性的表征手段和影响因素,归纳了超疏水表面的制备方法和相关的理论分析,对超疏水表面研究的发展进行了展望.     

地热水驱动双级有机闪蒸循环热性能研究

以R601、R601a、R123、R227ea、R245fa、R600、R600a、R236ea为循环工质,以150℃地热水作为热源温度,建立了双级OFC系统模型,对系统的热性能进行了研究,同时揭示了不同工质的低压级最优闪蒸压力.结果 表明,当循环工质为R601,高压级闪蒸压力为630.53 kPa时,双级OFC的净输...     

水凝胶中物质扩散过程研究进展

主要从模型理论和实验研究方法两个方面综述了国内外聚合物水凝胶中物质扩散行为研究进展.水凝胶中扩散理论模型主要有自由体积模型、流体力学模型、位阻效应模型三大类;实验研究方法主要分为间接法和实时法两种.     

A developed full-field fem analysis combined with ESPI for the investigation of defect evolution in polymer films

A full-field finite element method (FEM) analysis combined with electronic speckle pattern interferometry (ESPI) measurement was developed to investigate defect evolution in polymer films. Different from the previous reports, which only compare the ESPI experimental and FEM simulated results at several points or lines, herein the full-field FEM results were exported, subtracted with a continuous distribution. By choosing proper parameters and number of substeps, the simulated and experimental results showed excellent correspondence. Furthermore, the displacement fields vertical to the tensional direction were also presented, and the strain field was preliminarily evaluated. The current method of combination of ESPI and FEM allows for capturing the experimental fringe maps to validate and optimize FEM results simulated, and would give a higher security to structural and mechanical analysis of polymeric materials.     

聚苯胺基反射型柔性电致变色器件的制备与工艺研究

采用化学法合成聚苯胺(PANI),在柔性不锈钢丝网上进行涂覆,成功制备了反射型柔性变色器件.测试并获取了不同电位下(即不同的掺杂态)的紫外-可见光全反射光谱,比较确定了该变色器件合适的使用电压为+0.7V和-0.6V.并在选定的使用电压下对变色器件进行测试,讨论了工作电极上PANI用量、电解质层用量和离子储存层用量对变...     

可控变色织物制备及颜色控制研究

基于聚苯胺电致变色高聚物、采用反射型电致变色器件结构模型,以柔性导电织物作为电极,构建了可控变色织物,可在-1.0～+1.0 V低电压范围内实现颜色变化显著的黄色和绿色的可逆响应.系统研究了变色织物在不同电压、不同弛豫时间及不同颜色工作电极下的L*a*b*,ΔE*值及反射率曲线,且讨论了透射型电致变色器件和电致变色织物的区别.随着正电压的增加,变色织物对应的a*b*依次减小,蓝绿色加深;随着负电压的增加,变色织物对应的a*b*依次增加,变色织物黄色加深.撤去电压后变色织物发生放电弛豫,慢慢回复到未加电压时的本征态.工作电极底色对电致变色织物也有显著的影响.变色织物的断电放电弛豫时间低于透射型电致变色器件.