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在空间限域下的液晶物理学:穿透媒介,网络和未来

The physics of liquid crystals under confinement: Porous media, networks, and the future
课程网址: http://videolectures.net/clc2010_finotello_plcuc/  
主讲教师: Daniele Finotello
开课单位: 肯特州立大学
开课时间: 2010-08-05
课程语种: 英语
中文简介:
固体多孔主体中物理系统的研究可以追溯到几十年前,例如,研究珠宝商胭脂中的氦超流体转变。对多孔介质中超流体性质的研究保持了中心阶段,直到九十年代,他们不得不与限制液晶研究分享它们的优势(我们这些从事液晶工作的人都想相信这一点)。从应用的角度来看,液晶显示器可以说是一种更为人所知的受限物理系统。它们的操作很大程度上取决于液晶分子和主体固体表面之间的相互作用。从基本的角度来看,嵌入固体多孔材料或分散的纳米颗粒的液晶是非常丰富的系统,可以研究各种物理现象,包括对不同阶次相变的探测效应。这些现象包括相变的显着变化,特别是尺寸依赖的关键指数;表面诱导液晶排列;双层近晶生长双层;完整,准完全和部分润湿,以及分子构型转换等。应该提到的是,上述大部分实验工作都严重依赖于S. Zumer及其同事的理论贡献。具体而言,这些效果中的一些是通过NMR和交流量热法研究产生的,其中氰基联苯液晶嵌入在氧化铝Anopore或聚碳酸酯核孔膜的明确限定的圆柱形腔中;在随机互连的毛孔网络中,如Vycor和气凝胶眼镜;在Millipore过滤纤维素空隙或通过将球形二氧化硅纳米粒子Aerosil分散在液晶中;当然还有聚合物网络中的原始液晶。在回顾了上述一些研究之后,我们将讨论未来的研究可能。这些可以从将由金属纳米颗粒或纳米线形成的网络限制到光伏发电到药物递送到理解多孔介质中的反式到顺式光异构化转变。 *如果没有B. Zalar和S. Zumer在斯洛文尼亚卢布尔雅那大学和G. Iannacchione,T。Jin,S。Qian,H。Zeng和G. Crawford的许多贡献,这些研究是不可能实现的。肯特州立大学。
课程简介: Studies of physical systems in solid porous hosts date back several decades, for example, to studies of the helium superfluid transition in jewelers rouge. Research of the superfluid properties in porous media kept center stage until the nineties where they had to share their supremacy with confined liquid crystal studies (those of us working in liquid crystals would like to believe that). Point in case, from an applied perspective, a liquid crystal display is arguably one the better known confined physical systems. Their operation strongly depends on the interaction between the liquid crystal molecules and the host solid surfaces. From a fundamental point of view, liquid crystals imbedded in solid porous materials or with dispersed nanoparticles are incredibly rich systems that allow the study of a variety of physical phenomena including probing effects on different order phase transitions. These phenomena include dramatic changes at phase transitions and in particular, size-dependent critical exponents; surface-induced liquid crystal alignment; bilayer-by-bilayer smectic growth; complete, quasi-complete and partial wetting, and molecular configurational transitions, among others. It should be mentioned that much of the above experimental work heavily relied on the theoretical contributions of S. Zumer and his co-workers. Specifically, some of these effects were born out by NMR and ac calorimetry studies with cyanobiphenyl liquid crystals embedded in the well-defined cylindrical cavities of aluminum oxide Anopore or polycarbonate Nucleopore membranes; in the randomly interconnected networks of pores like in Vycor and Aerogel glasses; in the Millipore filter cellulose voids or by dispersing spherical silica nanometer particles, Aerosil, in the liquid crystal; and of course, the original liquid crystals in polymer networks. After reviewing some of the aforementioned studies, we will touch upon where future studies might be. These may range from confining networks formed from metallic nanoparticles or nanowires to photovoltaics to drug delivery to understanding trans-to-cis photo-isomerization transition in porous media. *These studies would not have been possible without the many contributions of B. Zalar and S. Zumer at the University of Ljubljana, Slovenia, and G. Iannacchione, T. Jin, S. Qian, H. Zeng, and G. Crawford at Kent State University.
关 键 词: 液晶物理学; 穿透媒介; 网络
课程来源: 视频讲座网
最后编审: 2019-01-23:chenxin
阅读次数: 113