Recently, the research team of Shi Quan from the Thermochemistry Research Group (DNL1903 group) of the Department of Hydrogen Energy and Advanced Materials Research, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Wu Zhongshuai from the Research Group of Two dimensional Material Chemistry and Energy Application (508 group) of the State Key Laboratory of Catalysis Foundation, and the team of Professor Chen Ying from Deakin University, Australia, cooperated to make new progress in the research of flexible fiber type phase change materials. The cooperation team prepared flexible graphene-boron nitride fiber-based phase change nonwovens through wet spinning and vacuum impregnation, and used them in wearable human thermal management devices. The composite phase change nonwoven fabric has excellent flexibility, heat storage capacity and permeability, providing a new idea for the research of intelligent wearable management devices.

Phase change energy storage materials can absorb and release a large amount of phase change latent heat at a relatively constant temperature, and can be used as thermal energy storage and temperature control media in the field of human thermal management. However, the inherent characteristics of traditional phase-change materials, such as liquid leakage, poor permeability and solid rigidity, make it difficult to apply phase-change energy storage materials to wearable intelligent thermal management devices.



In the construction of flexible wearable thermal energy storage and temperature control devices, Shi Quan's team has developed a variety of preparation methods, such as the preparation of intrinsic flexible solid-solid phase change film (Energy Storage Material., 2021) by chemical synthesis and the preparation of graphene-based flexible phase change film (Chem. Eng. J., 2021) by scraping and coating composite method. In this work, in order to further improve the permeability and energy storage density of phase change devices, on the basis of previous research, Shi Quan's team combined with Wu Zhongshuai's team's preparation technology of graphene three-dimensional porous assembly (ACS Nano, 2020; ACS Nano, 2019; Nano Energy, 2019; Energy Storage Material., 2019; J. Am. Chem. Soc., 2012), And taking advantage of the unique advantages of Chen Ying's team in the field of boron nitride nano-sheet preparation (Sci. Rep., 2016; Nat. Commun., 2015), the three teams worked together to put forward a general strategy for preparing high enthalpy flexible phase change nonwoven fabrics by wet spinning. The phase-change nonwoven fabric shows a high enthalpy of 206.0 J g-1, excellent thermal stability, a thermal cycling ability with an enthalpy retention rate of 97.6% after 1000 cycles, and an ultra-high water vapor permeability, which is superior to the currently reported phase-change material films and fibers. In addition, the phase-change nonwoven fabric can be applied to the wearable thermal management system of the human body in combination with the mask, which can keep the human body in a comfortable temperature range, showing the potential for application in the field of wearable thermal management of the human body, and providing a new direction for the development of wearable smart fabrics.



The relevant research results, entitled "A Thermography Flexible Phase Change Nonwoven for All-Season High-Efficiency Wearable Thermal Management", were recently published in the Nano-Micro Letters. The co-first authors of this work are Liu Hanqing, Ph.D. candidate of DNL1903 group and Zhou Feng, associate researcher of 508 group. The above research work was supported by the National Natural Science Foundation of China and the Innovation Fund of the Institute. (Text/picture Liu Hanqing, Zhou Feng)