Structure and Dynamics of Soft Condensed Matter

软凝聚态物质的结构与动力学

• 批准号: 121807-2012
• 负责人: Frisken, Barbara
• 金额: $ 2.99万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569228
• 关键词: Structure; Dynamics; Soft; Condensed; Matter

Liquid crystals, gels and lipid membranes are all examples of soft condensed matter, materials that are characterized by weak intermolecular interactions, mechanical softness, and a susceptibility to thermal fluctuations. Many of these materials are either two-dimensional, quasi-two dimensional, or fractal; are formed by self-assembly of smaller components such as particles, polymers or lipid molecules; and exhibit a rich range of behaviour including phase transitions, pattern formation, and non-linear material properties. They are also of great practical interest - contact lenses are made of polymeric gels, and liquid crystals form the basis for many display screens - and they can be used as models of more complicated biological systems. This field has the potential to produce both interesting physics and novel applications. Our focus is on the relationship between microscopic structure and macroscopic material properties in several systems. In this proposal, we plan to work in three areas. We will study the microstructure of polymer films formed from copolymers consisting of hydrophobic and conducting blocks; the goal of these studies is to achieve fundamental understanding of the relationship between microstructure and conductivity in ionic polymers, leading to informed design of these materials, which is critical for their application in polymer electrolyte membrane fuel cells. We are also starting studies of nanostructure in polymer films formed from blends of electron-donating polymers and molecular acceptors for application to organic photovoltaic devices. Again, the goal is to understand how the nanostructure is determined to inform design of better materials. A third research area explores the relationship between microstructure and rheology in yield-stress fluids, materials that flow or yield only when a critical stress is applied; everyday examples include mud, shaving foam and mayonnaise. We study the light scattered by these materials to study diffusion and elasticity at small length scales and to characterize the microstructure of the material. The goal of these studies is to uncover universal aspects of yield stress behaviour, leading to the development of microscopic theories.

液晶、凝胶和脂质膜都是软凝聚态物质的例子，这些材料的特点是分子间相互作用弱，机械柔软，对热波动敏感。这些材料中的许多要么是二维的，准二维的，要么是分形的；由颗粒、聚合物或脂质分子等较小组分的自组装形成；并表现出丰富的行为范围，包括相变，模式形成和非线性材料特性。它们也有很大的实用价值——隐形眼镜是由聚合凝胶制成的，液晶是许多显示屏的基础——它们可以用作更复杂生物系统的模型。这个领域有潜力产生有趣的物理和新颖的应用。