Rational Design and Manufacturing of Ceramic-Polymer Composites for Solid State Cooling using the Electrocaloric Effect

在被称为电热效应(ECA)材料的一类材料中，电流在材料中的流动可以在材料上产生温差。换句话说，如果一个人把电池连接到电热材料的两面，材料的一面会变暖，另一面会变冷。由于材料之间的温差，电热材料可用于制造冷却或加热设备，但与传统的加热和空调系统不同的是，电热设备可以在没有移动部件的情况下制造。基于欧洲经委会的冷却技术面临的一个主要挑战是缺乏高性能的电热材料，这些材料在制造过程中易于处理和成型，并且可以在室温下使用低功率运行。该奖项将支持开发聚合物复合材料(即与其他材料混合的聚合物)作为欧洲经委会材料的一种新形式，以克服这些挑战。该项目将培养能够在功能材料跨学科领域工作的研究生和本科生。研究成果将被纳入针对9-12年级教师和高中生的各种外展活动。本研究的目的是在铁电聚合物中引入陶瓷填料，以改善其室温电化学反应性能。将通过优化铁电-顺电相变和介电性能来设计和调整铁电聚合物和陶瓷的结构和组成，以提高ECEs的响应。将研究对填充物的空间取向的控制，以及这种性能取向的影响。将对所得到的结构和性能进行详细和系统的表征，以从根本上深入了解化学结构、薄膜形态、极化、介电响应和电热性能之间的关键关系。电活性聚合物纳米复合材料中独特的机理，如界面耦合效应，将被研究。该项目的成功将为高性能电致伸缩材料的开发开辟新的方向，并对开发具有新的结构和优异的耦合性能的新型聚合物纳米复合材料具有重要意义。

In the class of materials referred to as electrocaloric effect (ECE) materials, flow of an electric current through the material can create a temperature difference across the material. In other words, if one connects a battery to two sides of an electrocaloric material, one side of the material will become warmer and one side will become cooler. Because of this temperature difference across the material, electrocaloric materials can be used to build cooling or heating devices, but unlike conventional heating and air conditioning systems, electrocaloric devices can be fabricated with no moving parts. One major challenge to the ECE-based cooling technology is a lack of high-performance electrocaloric materials that are easily handled and shaped during manufacturing and that can be operated at room temperature using low amounts of power. This award will support the development of polymer composite materials (i.e. polymers that are mixed with other materials) as a new form of ECE materials to overcome these challenges. This project will train graduate and undergraduate students capable of working in the interdisciplinary field of functional materials. The research outcomes will be incorporated into various outreach activities for grades 9-12 teachers and high school students. This aim of this research is the introduction of ceramic fillers into ferroelectric polymers to improve room-temperature ECE responses. The structures and compositions of the ferroelectric polymer and ceramics will be designed and tuned to boost the ECE responses by optimizing the ferroelectric-paraelectric phase transition and the dielectric properties. Control over the spatial orientation of the fillers, and the effect of this orientation of performance, will be investigated. Detailed and systematic characterization of the resulting structures and properties will be carried out to gain fundamental insight into key relationships between chemical structure, film morphology, polarization, dielectric responses, and electrocaloric properties. Unique mechanisms in the electroactive polymer nanocomposites such as the interfacial coupling effect will be investigated. The success of this project will open a new direction in the development of high-performance ECE materials and have implications for development of novel polymer nanocomposites with new architectures and superior coupled properties.