CAREER: Liquid Crystal-Templated Sequential Infiltration Synthesis of Hybrid Organic/Inorganic Materials with Multidimensional Chiral Structures

职业：具有多维手性结构的有机/无机杂化材料的液晶模板连续渗透合成

• 批准号: 2337740
• 负责人: Xiao Li
• 金额: $ 71.5万
• 依托单位: University of North Texas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2337740&HistoricalAwards=false
• 关键词: CAREER; Liquid; Crystal; Templated; Sequential

NON-TECHNICAL ABSTRACTChirality is a geometric property of a molecule or structure that cannot be made to match its mirror image. It is widely prevalent in natural systems like DNA, proteins, and beetle shells. It is also of vital importance in diverse fields such as chiral mechanical and optical structures, bioseparation, and pharmaceuticals. Current exploration of chiral structures mostly involves molecular design and self-assembly of low mechanical strength organic materials. However, the kind of hybrid organic/inorganic materials with superior properties required for engineering applications are plagued by significant knowledge gaps in terms of synthesizing these materials. With this CAREER award, supported by the Solid State and Materials Chemistry program and the Condensed Matter Physics program, both in NSF’s Division of Materials Research, the principal investigator and her research group at the University of North Texas investigate new strategies for developing chiral hybrid materials by using abundant chiral liquid crystals (CLCs) as templates for nucleation and growth of these hybrid organic/inorganic materials. This is an integrated education-research program that centers on a fundamental understanding of the chemical reactions, physical behavior, and structural engineering involved in transforming LC morphologies into hybrid or fully inorganic materials; and revealing underlying structure-property relationships to unlock chirality-endowed multidimensional structures, as well as potentially novel optical and mechanical properties. The project promotes STEM education in soft-matter science and engineering, with a particular emphasis on engaging female and Hispanic students. By creating summer research opportunities, workshops and outreach activities, the principal investigator strives to include, inspire, and empower students from underrepresented groups, kindling their interests and participation in materials science. Activities are specifically designed to educate a new generation of scientists and engineers who better reflect the diversity of the Dallas-Fort Worth area, and to build a nationally-recognized soft-matter program in North Texas and beyond. TECHNICAL ABSTRACTChiral nematic or cholesteric phases in liquid crystals (LCs) exhibit asymmetrical packing of molecules, and thereby result in a finite twist angle between adjacent molecules and long-range chiral ordering similar to helical superstructures in DNA. The increase in chirality leads to the formation of 3D cubic symmetry, known as blue phases (BPs), that consist of double-twisted cylinders. The chiral properties of LCs (from nano to micrometers) are widely used in display technologies, electro-optics, and sensors. However, exploiting the full potential of such beneficial chiral structures to adapt to diverse engineering conditions, e.g., temperature, stress, and chemical environments, needs to overcome the inherently mechanically weak nature of LCs. In particular, the rapidly growing market for miniaturized device technologies requires materials with integrated flexibility and optical and mechanical performance at micro/nanoscale precision, all of which put CLCs in a more unique position than conventional solid crystalline materials. In this CAREER project, supported by the Solid State and Materials Chemistry program and the Condensed Matter Physics program, both in NSF’s Division of Materials Research, the principal investigator and her research group study novel reaction mechanisms facilitated by 2D/3D chiral templates to synthesize hybrid organic/inorganic materials with chirality across disparate length scales. The functional polar groups in mesogenic monomers used for LC structure polymerization serve as reactive moieties for sequential infiltration synthesis of metal oxides. The helical hierarchical and 3D lattice structures formed by highly chiral LCs, including BPs, guide the diffusion, nucleation, and growth of organometallic precursors inside the templates. By combining advanced experimental techniques and computational modeling, the research advances the fundamental understanding of thermodynamics, transport, and site selectivity of inorganic species in CLCs. Furthermore, the principal investigator studies the interplay among molecular architecture, synergistic self-assembly, and spatially controlled nucleation and growth of organic/inorganic species within complex multidimensional CLC/BP structures. This fundamental understanding allows the rational design of chiral-structured metal oxide-reinforced LC composites and unlocks their full potential in diverse application fields that include chiral optics, chiral mechanical devices, asymmetric catalysis, chiral separation and sensorsThis 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.

非技术摘要手性是分子或结构的一种几何特性，无法与其镜像相匹配，它在 DNA、蛋白质和甲虫壳等自然系统中广泛存在，在诸如DNA、蛋白质和甲虫壳等多种领域也至关重要。手性机械和光学结构、生物分离和药物目前对手性结构的探索主要涉及低机械强度有机材料的分子设计和自组装，但具有优异性能的有机/无机杂化材料。工程应用所需的性能受到合成这些材料方面巨大知识差距的困扰，该奖项由国家科学基金会材料研究部的固态和材料化学项目和凝聚态物理项目支持。和她在北德克萨斯大学的研究小组研究了通过使用丰富的手性液晶（CLC）作为这些杂化有机/无机材料的成核和生长的模板来开发手性杂化材料的新策略。是一项综合教育研究项目，重点关注将液晶形态转化为混合或全无机材料所涉及的化学反应、物理行为和结构工程，并揭示潜在的结构-性能关系，以解锁具有手性的多维结构；以及潜在的新颖光学和机械特性，该项目主要研究人员致力于通过创造夏季研究机会、研讨会和外展活动来促进软物质科学和工程领域的 STEM 教育，特别注重吸引女性和西班牙裔学生。到包括、激励和赋权来自代表性不足群体的学生，激发他们对材料科学的兴趣和参与，这些活动是专门为教育新一代科学家和工程师而设计的，他们可以更好地反映达拉斯-沃斯堡地区的多样性，并建立一个德克萨斯州北部及其他地区国家认可的软物质计划 技术摘要 液晶 (LC) 中的手性向列相或胆甾相表现出分子的不对称堆积，从而导致有限的分子堆积。相邻分子之间的扭转角和类似于 DNA 中螺旋超结构的长程手性排序，手性的增加导致形成 3D 立方对称性，称为蓝相 (BP)，由双扭转圆柱体组成。液晶（从纳米到微米）广泛应用于显示技术、电光和传感器，然而，充分利用这种有益的手性结构的潜力来适应不同的工程条件，例如，温度、应力和化学环境，需要克服液晶固有的机械弱点，特别是，快速增长的小型化器件技术市场需要具有微米/纳米级精度的集成灵活性和光学和机械性能的材料。 CLC 比传统固体晶体材料处于更独特的地位。在这个 CAREER 项目中，首席研究员和她得到了 NSF 材料研究部的固态和材料化学项目和凝聚态物理项目的支持。研究小组研究了由2D/3D手性模板促进的新颖反应机制，以合成具有不同长度尺度的手性杂化有机/无机材料，用于液晶结构聚合的介晶单体中的功能性极性基团作为连续渗透合成金属氧化物的反应部分。由高度手性液晶（包括 BP）形成的螺旋分层和 3D 晶格结构，引导扩散、成核和生长。通过结合先进的实验技术和计算模型，该研究推进了对 CLC 中无机物质的热力学、输运和位点选择性的基本理解。这种基本的理解使得手性结构金属氧化物增强的合理设计成为可能。 LC 复合材料并释放其在手性光学、手性机械装置、不对称催化、手性分离和传感器等不同应用领域的全部潜力该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。