Nanoscale Organic Hybrid Materials (NOHMs)

技术综述：纳米有机杂化材料(NOHMs)是一种星形支化有机聚合物，其核心是无机纳米颗粒。通过系统地改变星臂(电晕)的分子量、重复单元化学和接枝密度和/或核心颗粒的大小、形状和质量分布(例如中空核心)，可以很容易地调节无机组分的体积分数，以操纵杂化材料的整体机械性能、导电性和结构。光谱的一端是具有高颗粒含量的材料，它们显示出类似于玻璃、硬蜡和凝胶的特性。在另一个极端是自发形成颗粒满载的、无溶剂的流体的系统，其特征是定义明确的牛顿流动状态和类似于由分子组成的简单液体的传输特性。NOHMS在杂化纳米材料中是独一无二的，因为它们形成了均匀的液体，这些液体是纳米级构建块的长度尺度的杂化。这项研究采用实验和理论相结合的方法来了解NOHMS核和日冕的几何特征如何影响其平衡结构因子、离子输运性质、流变学和界面行为。该研究还使用NOHMS作为模型系统，用于研究稠密胶体悬浮液中的软玻璃流变学、慢动力学和堵塞。非技术概述：该项目专注于最近发现的有机/无机杂化材料家族，该材料在单一平台中集成了塑料的轻质和低成本特性与无机纳米颗粒的机械强度和电稳定性。被称为纳米级有机杂化材料(NOHMs)的这些杂化材料有望成为下一代高性能锂电池的电解液，以及作为军事和执法人员的轻型防刺穿防弹衣。要利用NOHMS在这两种应用中的优势，必须对其结构和物理性质有一个全面的了解。拟议的研究通过使用实验和理论工具相结合的方式来实现这一目标，以建立材料的性能与其基本构件的化学之间的关系。研究人员建议利用这些关系来指导新的NOHMS系统的设计，明确控制与锂电池和防刺穿涂层应用相关的特性。他们还建议开发基于NOHMS在电池和防弹衣中的应用的演示实验，这些实验将用于接触高中生，以提高他们对STEM职业的兴趣。

TECHNICAL SUMMARY:Nanoscale organic hybrid materials (NOHMs) are star-branched organic polymers where the core of the star is an inorganic nanoparticle. By systematically changing the molecular weight, repeat unit chemistry, and grafting density of the star arms (corona) and/or the core particle size, shape, and mass distribution (e.g. hollow cores), the volume fraction of the inorganic component can be facilely adjusted to manipulate overall mechanical properties, conductivity, and structure of the hybrids. On one end of the spectrum are materials with high particle contents, which display properties similar to glasses, stiff waxes, and gels. At the opposite extreme are systems that spontaneously form particle-laden, solvent-free fluids characterized by a well-defined Newtonian flow regime and transport properties similar to simple liquids comprised of molecular building blocks. NOHMs are unique among hybrid nanomaterials because they form homogeneous liquids that are hybrids down to length-scales of the nanometer-sized building blocks. The proposed research uses a combination of experiments and theory to understand how geometric features of the NOHMs core and corona influence their equilibrium structure factor, ion transport properties, rheology, and interfacial behavior. The study also uses NOHMs as model systems for investigating soft glassy rheology, slow dynamics, and jamming in dense colloidal suspensions.NON-TECHNICAL SUMMARY: This project focuses on a recently discovered family of organic/inorganic hybrid materials which integrate - in a single platform - lightweight and low-cost features of plastics with mechanical strength and electrical stability of inorganic nanoparticles. Termed nanoscale organic hybrid materials (NOHMs), these hybrids show promise as electrolytes for next-generation, high-performance lithium batteries and as lightweight, puncture-resistant body armor for military and law-enforcement personnel. To take advantage of NOHMs in either application, it is essential to develop a comprehensive understanding of their structure and physical properties. The research proposed achieves this goal by using a combination of experimental and theoretical tools to establish relationships between properties of the materials and chemistry of their basic building blocks. The investigators propose to use these relationships to guide design of new NOHMs systems with explicit control of properties relevant for applications in lithium batteries and puncture-resistant coatings. They also propose to develop demonstration experiments based on applications of NOHMs in batteries and body armor that will be used to reach-out to high school students to increase interest in STEM careers.