清华剑桥合作制备易加工的液晶弹性体智能材料

正液晶弹性体材料在热、光、电、磁等外界刺激下可发生形状的自发改变,作为致动器及感应器在人工肌肉、柔性机器人、盲人显示器等诸多领域的应用前景十分广阔。这种形状的改变是基于高分子内部的液晶有序性,通过光、热、磁等方式改变这种有序性将产生可逆的宏观形状变化。为了使液晶弹性体发生实际意义的形状改变,必须将液晶高分子链作单畴取向(单畴是指液晶分子链中很窄的或单一取向的区域)。传统的两步交联法、外场和界面条件交联法等制备单畴液晶弹性体的工艺,或工艺复杂并成功率低,或仅适用于微米级样品。正因如此,长久以来,这种液晶弹性体材料在现实生活中     

清华剑桥合作制备易加工的液晶弹性体智能材料

正液晶弹性体材料在热、光、电、磁等外界刺激下可发生形状的自发改变,作为致动器及感应器在人工肌肉、柔性机器人、盲人显示器等诸多领域的应用前景十分广阔。这种形状的改变是基于高分子内部的液晶有序性,通过光、热、磁等方式改变这种有序性将产生可逆的宏观形状变化。为了使液晶弹性体发生实际意义的形状改变,必须将液晶高分子链作单畴取向(单畴是指液晶分子链中很窄的或单一取向的区域)。     

脉冲软X射线辐射下复合材料的辐射特性实验研究

采用自行研制的微型红外通光测试系统,对三种复合材料和硬铝在脉冲软X射线辐射下的喷射冲量进行了实验测量研究.结果表明:涂层B较涂层A、玻璃钢和硬铝具有更好的抗脉冲辐射性能;在实验能注量范围内涂层B的烧蚀率只是涂层A的十分之一,是硬铝的三分之一.可以断定,涂层B是空间飞行器的最好防护层材料之一.     

热-力-粘弹耦合多孔FGVM梁的动力学特性

研究了初始轴向机械力作用下三参数Winkler-Pasternak粘弹性地基上多孔功能梯度粘弹性材料(FGVM)梁在热环境中的自由振动特性.考虑满足热传导方程的稳态温度分布以及材料性质的温度相关性,采用Kelvin-Voigt模型并由含孔隙率修正的混合幂率梯度分布来表征内含均匀孔隙FGVM梁的材料属性.基于n阶广义梁理...     

大的双折射色散液晶材料

介绍了影响液晶双折射色散的因子及大双折射色散液晶材料的研究现状     

光刻法制备聚合物/液晶光栅

将明胶涂覆在表面经过取向处理的带有ITO电极的玻璃基板上,以紫外灯为光源,通过光掩模法,使明胶在光场的引发下发生光化学反应,样品显影刻蚀处理后呈栅状,将液晶注入光栅盒中,形成聚合物／液晶光栅。该光栅衍射效率可利用电场调控。采用He—Ne激光器对所制样品进行测试,结果表明,所制样品的栅结构较好。避免了液晶与聚合物相分离的不完全性和栅条边缘不整齐的现象。制得的光栅其第一衍射级次的开关比为87：1,显示了较好的开关能力。     

Tunable lasing from a cholesteric liquid crystal film embedded with a liquid crystal nanopore network

Continuous tuning of lasing wavelength is achieved in cholesteric liquid crystal lasers by embedding a network of nanopores with an average size of 10 nm filled with liquid crystals inside a polymerized matrix with helical order. The device possesses both high transparency and a fast response time because the tuning is driven by local reorientation of the liquid crystal molecules in the nanopores.     

计算全息再现中LCD黑栅效应的研究

在基于LCD再现的计算全息中,由于TFT-LCD固有的像素结构形成一个二维黑栅矩阵,其衍射作用会引入阵列分布的多个像,即黑栅效应,影响再现像的像质.通过理论推导,具体分析了LCD黑栅效应对全息再现像的影响;提出像素分解法,分别模拟理想再现和基于LCD再现的过程,得到相应的数字再现像.并对其进行了比较和分析,给出了分析结果,证实了LCD黑栅效应对再现像的影响.     

带端烯基席夫碱液晶化合物的合成与表征

通过取代、还原、加成等反应,合成了一种带端烯基的席夫碱液晶化合物4-烯丙氧基苯亚甲基(-4'-丁氧基)苯胺.用IR和1HNMR对该液晶化合物的结构进行了表征,用DSC和热台偏光显微镜(POM)对该化合物的液晶行为进行了分析,结果表明,4-烯丙氧基苯亚甲基(-4'-丁氧基)苯胺是一种单向性近晶型液晶.     

壳聚糖-明胶液晶复合支架性能

液晶态普遍存在于生物体中,为开发新型生物支架材料和更好地模拟生物体内微环境,从仿生角度出发,制备出壳聚糖-明胶液晶复合支架;采用偏光显微镜、扫描电镜和分析天平分别表征了其织构和形态、孔隙率和吸水性。实验结果表明,壳聚糖-明胶质量比为7:3液晶支架呈现典型的胆甾相液晶织构,孔隙率和吸水性分别在95%和85%左右;其性能优于其他配比的液晶复合支架。     

Sidechain liquid crystal polymers

Research has continued in the field sidechain liquid crystal polymers over recent years, but it is becoming clearer that this research is being directed away from the traditional technology areas of electro-optic devices and researchers are developing new and exciting applications for this novel state of matter.     

含侧甲基液晶双马来酰亚胺的合成及表征

通过甲基对苯二酚和对马来酰亚胺基苯甲酸,制得了一种低熔点的酯类液晶双马来酰亚胺.应用FT-IR、1H-NMR、DSC、HSPM对液晶双马来酰亚胺的结构和液晶行为进行了表征.结果表明,这类液晶双马来酰亚胺具有较低的熔点,侧甲基的存在使得液晶双马来酰亚胺的熔点下降了39℃.由HSPM观察到所合成的液晶单体具有向列型液晶所具有的典型的纹影织构,呈现出较好的热致液晶行为,并且液晶织构可以通过端基的交联聚合反应固定在交联网络中.     

The liquid crystal injection scheduling problem (LCISP)

In this paper, the liquid crystal injection scheduling problem (LCISP) involving the constraints on limited maximum waiting times, unequal ready times, and machine setup times is considered to form the batches with incompatible product families and to sequence those batches on identical parallel batch processing machines. The batch scheduling problem, LCISP, has many applications, especially in thin film transistor liquid crystal display (TFT-LCD) factories at the cell assembly stage. In the LCISP, the objective is to minimise the total machine workload without violating the limited maximum waiting time restriction. Furthermore, machine setup times that are sequence dependent for two consecutive batches classified into different product families on the same machine are also considered. Since the LCISP involves constraints on limited maximum waiting times and sequence dependent setup times, it is more difficult to solve than the classical parallel batch processing machine scheduling problem with incompatible product families. These restrictions mean that the existing methods cannot be applied into real-world factories directly. Therefore, this paper proposes a mixed integer programming model to solve the LCISP exactly. In addition, two efficient solution procedures which solve the LCISP are also presented.