Nanoscale Organic Hybrid Materials (NOHMs)

技术概述：纳米级有机杂化材料（NOHM）是星形支化的有机聚合物，其中星星的核心是无机纳米颗粒。通过系统地改变星星臂（冠）的分子量、重复单元化学和接枝密度和/或核颗粒尺寸、形状和质量分布（例如中空核），可以容易地调节无机组分的体积分数以操纵杂化物的总体机械性能、导电性和结构。在光谱的一端是具有高颗粒含量的材料，其显示类似于玻璃、硬蜡和凝胶的性质。在另一个极端是自发形成负载颗粒的无溶剂流体的系统，其特征在于明确定义的牛顿流动状态和类似于由分子构建块组成的简单液体的传输性质。NOHM在混合纳米材料中是独特的，因为它们形成均匀的液体，这些液体是纳米尺寸构建块的长度尺度的混合物。 拟议的研究使用实验和理论相结合，以了解NOHM核心和电晕的几何特征如何影响其平衡结构因子，离子传输特性，流变学和界面行为。该研究还使用NOHM作为模型系统，用于研究软玻璃态流变学、慢动力学和致密胶体悬浮液中的堵塞。 该项目的重点是最近发现的有机/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以及无机纳米颗粒的机械强度和电稳定性。这些混合物被称为纳米级有机混合材料（NOHM），有望成为下一代高性能锂电池的电解质，以及军事和执法人员的轻质防穿刺防弹衣。为了在任一应用中利用NOHM，必须全面了解其结构和物理性质。该研究通过使用实验和理论工具的组合来实现这一目标，以建立材料特性与其基本构建块化学之间的关系。研究人员建议使用这些关系来指导新的NOHMs系统的设计，并明确控制与锂电池和耐穿刺涂层应用相关的性能。 他们还建议开发基于NOHM在电池和防弹衣中应用的演示实验，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.