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.
