U.S.-Hungary Materials Research: Liquid Crystalline Mesophases of Bent Core Molecules

这项由肯特州立大学的彼得·帕尔菲-穆霍雷和匈牙利固态物理与光学研究所布达佩斯的艾格尼丝·布尔卡领导的美国-匈牙利研究项目研究了一类由椭圆形分子组成的新型液晶。 这些酯型弯芯液晶的范围从低分子量材料到弹性体。合作研究计划包括合成，表征和建模这样的核，或香蕉形，分子。来自肯特州立大学的年轻研究人员是杰出的美国和匈牙利团队的一部分。为了确定双核液晶的中间相和物理性质，研究伙伴将采用三种实验技术：1）薄膜的力学研究，包括香蕉液晶系统的线性机电和流变学测量，其中整体手性由表面相互作用确定。2)电气测量，包括极化和介电谱的测定。 3)光学观测包括偏振和共焦显微镜以及电光测量和激光光谱。 我们的目标是解决一些基本问题，材料参数和图案形成不稳定性之间的相关性。 例如，研究人员希望解释所观察到的非手性断裂机制，并了解这些结构如何在各向同性熔体中形成螺旋丝。 如果成功，他们的结果可能有助于识别具有光学和热电特性的新型合成材料，这些材料在信息技术和生物技术中具有实际应用。这个实验凝聚态物理学的研究项目实现了通过使美国和中欧的专家联合收割机互补人才和共享研究资源来推进科学知识的计划目标。

This US-Hungarian research project headed by Peter Palffy-Muhoray of Kent State University and Agnes Burka of the Hungarian Institute for Solid State Physics and Optics Budapest examines a new class of liquid crystals consisting of bent-shaped molecules. These ester type bent core liquid crystals range from low molecular weight materials to elastomers. The collaborative research plan involves synthesis, characterization, and modeling of such bent-core, or banana-shaped, molecules. Junior researchers from Kent State University are part of the distinguished US-Hungarian team.To determine the mesophases and physical properties of bent-core liquid crystals, the research partners will employ three experimental techniques: 1)Mechanical studies of thin films including linear electro-mechanical and rheological measurements of banana liquid crystal systems, where the overall chirality is set by surface interactions. 2)Electrical measurements which include determination of the polarization and dielectric spectroscopy. 3)Optical observations consisting of polarizing and confocal microscopy as well as electro-optic measurements and laser spectroscopy. The goal is to resolve a number of fundamental questions concerning the correlation between material parameters and pattern forming instabilities. For example, the researchers hope to explain observed achiral symmetry-breaking mechanisms and to understand how the structures form helical filaments in an isotropic melt. If successful, their results may help identify novel synthetic materials with optical and pyroelectric properties that have practical applications in information technology and biotechnology. This research project in experimental condensed matter physics fulfills the program objective of advancing scientific knowledge by enabling experts in the United States and Central Europe to combine complementary talents and share research resources in areas of strong mutual interest and competence.