Liu Yifan, Lv Zhisheng, Zhou Jiazuo, Cui Zequn, Li Wenlong, Yu Jing, Chen Lixun, Wang Xin, Wang Meng, Liu Kunyang, Wang Hui, Ji Xinyao, Hu Senwei, Li Jian, Loh Xian Jun, Yang Haiyue, Chen Xiaodong, Wang Chengyu
Key Laboratory of Bio-Based Material Science and Technology of Ministry of Education, Northeast Forestry University, Harbin, 150040, P. R. China.
Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634, Singapore.
Adv Mater. 2024 Sep;36(39):e2406915. doi: 10.1002/adma.202406915. Epub 2024 Aug 3.
Phase change materials (PCMs) are crucial for sustainable thermal management in energy-efficient construction and cold chain logistics, as they can store and release renewable thermal energy. However, traditional PCMs suffer from leakage and a loss of formability above their phase change temperatures, limiting their shape stability and versatility. Inspired by the muscle structure, formable PCMs with a hierarchical structure and solvent-responsive supramolecular networks based on polyvinyl alcohol (PVA)/wood composites are developed. The material, in its hydrated state, demonstrates low stiffness and pliability due to the weak hydrogen bonding between aligned wood fibers and PVA molecules. Through treatment of poly(ethylene glycol) (PEG) into the PVA/wood PEG gel (PEG/PVA/W) with strengthened hydrogen bonds, the resulting wood-based PCMs in the hard and melting states elevate the tensile stress from 10.14 to 80.86 MPa and the stiffness from 420 MPa to 4.8 GPa, making it 530 times stiffer than the PEG/PVA counterpart. Capable of morphing in response to solvent changes, these formable PCMs enable intricate designs for thermal management. Furthermore, supported by a comprehensive life cycle assessment, these shape-adaptable, recyclable, and biodegradable PCMs with lower environmental footprint present a sustainable alternative to conventional plastics and thermal management materials.
相变材料（PCM）对于节能建筑和冷链物流中的可持续热管理至关重要，因为它们可以存储和释放可再生热能。然而，传统的相变材料在其相变温度以上会出现泄漏和成型性丧失的问题，限制了它们的形状稳定性和多功能性。受肌肉结构的启发，基于聚乙烯醇（PVA）/木材复合材料开发了具有分级结构和溶剂响应超分子网络的可成型相变材料。该材料在其水合状态下，由于排列的木纤维和PVA分子之间的氢键较弱，表现出低刚度和柔韧性。通过将聚乙二醇（PEG）处理到具有强化氢键的PVA/木材PEG凝胶（PEG/PVA/W）中，所得的硬态和熔融态木基相变材料的拉伸应力从10.14 MPa提高到80.86 MPa，刚度从420 MPa提高到4.8 GPa，使其比PEG/PVA对应物硬530倍。这些可成型的相变材料能够响应溶剂变化而变形，从而实现复杂的热管理设计。此外，在全面的生命周期评估的支持下，这些形状适应性强、可回收和可生物降解的相变材料具有较低的环境足迹，是传统塑料和热管理材料的可持续替代品。
