Collaborative Research: Morphogenesis of First-Order Phase Transitions in Polar and Apolar Nematic Liquid Crystals

合作研究：极性和非极性向列液晶中一级相变的形态发生

• 批准号: 2106675
• 负责人: Oleg Lavrentovich
• 金额: $ 24.17万
• 依托单位: Kent State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2106675&HistoricalAwards=false
• 关键词: Collaborative; Research; Morphogenesis; First; Order

Liquid crystals are composed of rod-like or disc-like molecules that enable these materials to behave in some ways like a liquid and in others like a solid. This project is an exploration of the fundamental problem of analyzing the configurations observed in phase transitions in liquid crystals. Principally, the project will elucidate how the shape of the interface between different phases is determined by a balance of elastic forces and surface tension. The results will be of importance in mathematics, physics, and materials science since development of various morphologies in coexisting phases is a ubiquitous natural phenomenon. The acquired knowledge will bring about new and powerful tools to experimentally control these morphologies, leading to new and exciting applications. This interdisciplinary program further provides opportunities to educate students in the mathematics and physics of liquid crystals. The project will focus on the characterization and description of the overall shape and internal structure of soft condensates representing nuclei of the orientationally ordered phases shaped by bulk elasticity with disparate elastic moduli and anisotropic surface tension. The proposed work will consider a broad spectrum of liquid crystals, embracing nematic and cholesteric liquid crystals that are described by non-orientable director line fields and experience transitions into partially positionally ordered phases, and newly discovered ferroelectric nematic liquid crystals that are described by the director and a vector-valued electric polarization. The mathematical emphasis is on the analysis of stationary variational problems for energies defined over vector- and tensor-valued fields in two and three dimensions and associated gradient flows, so as to describe the equilibrium configurations of liquid crystals and dynamics of interfaces in a plethora of their phase transitions. The principal novelty of the proposed work is that it will consider singular limits of liquid crystal energies that impose severe geometric rigidity on admissible classes of functions. The primary challenges to the analysis arise due to high dimensionality of a target space and the need to consider singular asymptotic limits that result in highly nonlinear constraints. The combined analytical/experimental approach will be essential in that it will provide a clear check of success for the analytical predictions; these predictions, in turn, will guide the experiments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

液晶由棒状或盘状分子组成，这些分子使这些材料在某些方面表现得像液体，而在其他方面则像固体。本项目是对分析液晶相变中观察到的构型这一基本问题的探索。 主要是，该项目将阐明不同相之间的界面形状是如何由弹性力和表面张力的平衡决定的。这些结果在数学、物理学和材料科学中具有重要意义，因为在共存相中各种形态的发展是一种普遍存在的自然现象。所获得的知识将带来新的和强大的工具来实验控制这些形态，导致新的和令人兴奋的应用。这个跨学科的计划进一步提供了机会，教育学生在液晶的数学和物理。该项目将侧重于表征和描述软凝聚物的整体形状和内部结构，软凝聚物代表由具有不同弹性模量和各向异性表面张力的体弹性形成的取向有序相的核。拟议的工作将考虑一个广谱的液晶，拥抱非取向的导演线场和经验的过渡到部分位置有序的阶段，和新发现的铁电液晶描述的导演和矢量值的电极化描述的双折射和双折射液晶。数学的重点是分析定常变分问题的能量定义在矢量和张量值的领域在二维和三维和相关的梯度流，以描述平衡配置的液晶和动态的接口在他们的相变过多。所提出的工作的主要新奇在于，它将考虑奇异的液晶能量的限制，施加严重的几何刚性上容许类的功能。分析的主要挑战是由于目标空间的高维性以及需要考虑导致高度非线性约束的奇异渐近极限。分析/实验相结合的方法将是必不可少的，因为它将为分析预测的成功提供明确的检查;这些预测反过来将指导实验。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

项目成果

Gemini surfactant behavior of conventional surfactant dodecyltrimethylammonium bromide with anionic azo dye Sunset Yellow in aqueous solutions

• DOI: 10.1016/j.molliq.2022.119556
• 发表时间: 2022-06
• 期刊: Journal of Molecular Liquids
• 影响因子: 6
• 作者: E. Akpinar;Nazli Uygur;Gokhan Topcu;O. Lavrentovich;Antônio Martins Figueiredo Neto

Defects in bent-core liquid crystals

弯芯液晶的缺陷

• DOI: 10.1080/21680396.2022.2086932
• 发表时间: 2022
• 期刊: Liquid Crystals Reviews
• 影响因子: 5.1
• 作者: Jákli, Antal;Nastishin, Yuriy;Lavrentovich, Oleg D.
• 通讯作者: Lavrentovich, Oleg D.

Instantaneous mapping of liquid crystal orientation using a polychromatic polarizing microscope

使用多色偏光显微镜瞬时绘制液晶取向

• DOI: 10.1080/02678292.2022.2142883
• 发表时间: 2023
• 期刊: Liquid Crystals
• 影响因子: 2.2
• 作者: Rajabi, Mojtaba;Lavrentovich, Oleg;Shribak, Michael
• 通讯作者: Shribak, Michael

Toroidal nuclei of columnar lyotropic chromonic liquid crystals coexisting with an isotropic phase

• DOI: 10.1039/d2sm00712f
• 发表时间: 2022-07-29
• 期刊: SOFT MATTER
• 影响因子: 3.4
• 作者: Koizumi, Runa;Golovaty, Dmitry;Lavrentovich, Oleg D.
• 通讯作者: Lavrentovich, Oleg D.