基于尼龙络合物新型电卡材料的制备及其高电卡强度和巨电卡效应的研究

As electrocaloric cooling is an environmentally friendly solid-state refrigeration technology with high energy efficiency, the research of electrocaloric material with high electrocaloric strength and giant electrocaloric effect has been the most pressing subject to commercialize electrocaloric cooling technology. Amorphous nylon complexes are prepared by compounding metal salts or nano-scale ionic liquids and nylon 6 or nylon 66 in this project. And then electrocaloric material with high electrocaloric strength and giant electrocaloric effect will be prepared by utilizing its crystallization result from complex dissociation upon application of an electric field and complexing again upon removal of an electric field. The correlation between compounding technology, composition, ionic species, complexation and the crystallinity of nylon complexes will be investigated. After that, the control technology of the crystalline of nylon complexes and the preparation method of amorphous nylon complexes will be established. The ion migration, complex dissociation, crystallization and temperature change of nylon complexes upon application of an electric field and complexing again between nylon and ion and temperature change upon removal of an electric field will be explored. The relationship between crystallinity change and ionic species, complexation as well as electric field strength will be made a thorough inquiry. Furthermore, we will build the corresponding relationship between the temperature change and crystallinity change, and then shed lights on the formation mechanism of high electrocaloric strength and giant electrocaloric effect. Finally, electrocaloric cooling devices will be designed and fabricated. This project will provide both theoretical and technical supports for the design, preparation and application of functional materials with high electrocaloric strength and giant electrocaloric effect.

电卡制冷是一种环保、能源利用率高的固态制冷技术，研发出具有高电卡强度和巨电卡效应的材料是实现电卡制冷技术商业应用最紧迫课题。本项目拟将金属盐及纳米离子液体与尼龙6及尼龙66复合制备出非晶态尼龙络合物，利用这种络合物在电场作用下解络合而结晶和去电场再络合的特性，制备出高电卡强度和巨电卡效应的材料。研究复合工艺、组成、离子种类以及络合作用与尼龙络合物结晶度的关联，构建尼龙络合物结晶度的调控技术和非晶态尼龙络合物的制备技术；研究电场作用下尼龙络合物中离子的迁移过程、解络合作用、尼龙的结晶和温变以及去电场后尼龙与离子的再络合作用和温变，探明材料结晶度变化与离子种类、络合作用和电场强度的关联，并建立材料的温变与材料结晶度变化的对应关系，阐明尼龙络合物的高电卡强度和巨电卡效应形成机制；设计并制备电卡制冷器件。该项目将为具有高电卡强度和巨电卡效应的功能材料的设计、制备和应用提供科学理论和实用技术。

电卡制冷是一种制冷效率高、环境友好的固态制冷技术，研发出具有高电卡强度和巨电卡效应的材料是实现电卡制冷技术商业应用最紧迫课题。本项目拟将金属盐与聚酰胺复合制备出非晶态尼龙络合物，利用这种络合物在电场作用下解络合而结晶和去电场再络合的特性，制备出高电卡强度和巨电卡效应的材料。基于非晶态-结晶态转变过程，可以根据尼龙结晶度变化和焓变来计算尼龙络合物电卡效应的理论温变和熵变。在聚酰胺种类、金属盐种类、制备工艺以及各种改性材料等方面分别进行了详细的研究。通过溶液-流延法和熔融-压延法制备了尼龙6/CaCl2薄膜材料，通过微量热仪测得尼龙6/CaCl2膜在0.8 kV cm-1电场下产生的ΔT为18.2 K，表现出巨电卡效应，其电卡强度为22.8 K cm kV-1，是目前报道最高值的近100倍，而且所需要的电场强度也远低于传统的电卡材料。选择聚酰胺的良溶剂氯乙醇与聚酰胺金属络合物制备了高分子凝胶，研究块状材料的电卡效应。该项目将为具有高电卡强度和巨电卡效应的功能材料的设计、制备和应用提供科学理论和实用技术。