CAREER: Design Rules for Electrical Transport in Suspensions of Conductive Particles

软材料由微观的建筑块组成，它们之间的纳米级相互作用可以被设计成产生完全不同的材料行为。悬浮液是一类含有分散在流体中的固体颗粒的软材料。新型电化学储能技术的发展使人们对理解含有导电纳米和微颗粒的悬浮液的性质重新产生了兴趣，特别是对于需要具有低粘度和高导电性的悬浮液的应用。虽然致密悬浮液的流变学有坚实的理论和实验基础，但其电学性质却鲜为人知。这种知识差距为设计具有最佳性能的悬架提供了独特的挑战和机遇。该项目将通过将新的合成技术与先进的结构和电学表征方法相结合来解决这一挑战，以弥合目前在理解导电粒子流体悬浮液中的电子传输方面的差距。该项目还将为未来的劳动力提供软材料特性的基础知识，以及它们在新兴和当代社会挑战中的潜在应用。受最近对极性和非极性溶剂中炭黑悬浮液的流变电测量的启发，该项目将测试粒子动力学在导电粒子的流体悬浮液中介导电子传递方面发挥重要作用的假设。我们的目标是用三种新方法来检验这一假设。新的合成方法将控制导电纳米和微颗粒之间的大小、形状和相互作用，而新的流变电表征技术将允许直接量化电输运特性。这些新的合成和表征方法将通过使用小角散射技术进行微结构测量来增强。这三种方法的结合将导致设计规则的发展，这些规则可用于设计用于电化学储能技术和其他有用目的的悬浮液的电气特性。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

Soft materials consist of microscopic buildings blocks whose nanoscale interactions can be engineered to yield radically different material behaviors. Suspensions are one class of soft material that contain solid particles dispersed in a fluid. The development of new electrochemical energy storage technologies has generated renewed interest in understanding the properties of suspensions containing electrically conductive nano- and micro- particles, especially for applications requiring suspensions that exhibit low viscosity and high electrical conductivity. While the rheology of dense suspensions has a firm theoretical and experimental basis, the electrical properties are less well understood. This knowledge gap presents a unique challenge and opportunity to design suspensions with optimal properties. This project will address this challenge by combining new synthesis techniques with advanced structural and electrical characterization methods to bridge the current gap in understanding electron transport in fluid suspensions of conducting particles. This project will also prepare the future workforce with foundational knowledge in the properties of soft materials and their potential application to emerging and contemporary societal challenges.Motivated by recent rheo-electric measurements of suspensions of carbon black in polar and non-polar solvents, this project will test the hypothesis that particle dynamics play a significant and underappreciated role in mediating electron transport in fluid suspensions of conducting particles. The objective will be to test this hypothesis with three novel approaches. New synthetic approaches will control the size, shape, and interactions between conductive nano- and micro-particles, while new rheo-electric characterization techniques will allow for direct quantification of electrical transport characteristics. These new synthetic and characterization approaches will be augmented by microstructural measurements using small angle scattering techniques. The combination of these three approaches will result in the development of design rules that can be used to engineer the electrical properties of suspensions for electrochemical energy storage technologies and other useful purposes.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.