Li Yongle, Zhang Chengliang, Zhou Tongtong, Zhao Pengyu, Huang Tao, Wang Dunhui
Hangzhou Dianzi University, Hangzhou 310018, China.
National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
J Phys Chem B. 2024 Sep 26;128(38):9297-9303. doi: 10.1021/acs.jpcb.4c05218. Epub 2024 Sep 17.
The barocaloric effect of a solid material is an intense research topic due to its potential application in solid-state refrigeration. Among the proposed candidates, elastic polymers are distinctive because their barocaloric responses are independent from a pressure-induced phase transition which makes it possible to realize a broad working temperature range in principle. However, the barocaloric performance of most elastic polymers diminishes significantly as temperature decreases. In this work, giant and reversible barocaloric effects were observed in a broad working temperature range from 252 to 345 K in an amorphous polymer of ethylene propylene diene monomer, which are much higher than the investigated crystalline and partially crystallized ones. It is demonstrated that the degree of crystallinity can be a key factor responsible for the mobility of polymer chains and the corresponding barocaloric performance at low temperatures. The reversible giant barocaloric effects, broad working temperature regions, low cost, and absence of pressure-transmitting fluid make the ethylene propylene diene monomer attractive for solid-state barocaloric refrigeration.
由于固态制冷中的潜在应用，固体材料的压热效应是一个热门研究课题。在已提出的候选材料中，弹性聚合物很独特，因为它们的压热响应与压力诱导的相变无关，这使得原则上实现宽工作温度范围成为可能。然而，随着温度降低，大多数弹性聚合物的压热性能会显著下降。在这项工作中，在乙烯-丙烯-二烯单体无定形聚合物中，于252至345K的宽工作温度范围内观察到了巨大且可逆的压热效应，这比所研究的结晶和部分结晶聚合物的效应要高得多。结果表明，结晶度可能是影响低温下聚合物链流动性及相应压热性能的关键因素。可逆的巨大压热效应、宽工作温度区域、低成本以及无需传压流体，使得乙烯-丙烯-二烯单体对固态压热制冷具有吸引力。
