摘要
人体微环境调控可以通过材料本身性能的调控实现穿着凉爽舒适,对提高生活品质、减少碳排放具有重要价值.然而传统材料仅能单向地实现致冷或保温,同一材料实现致冷、保温双向功能,依然是本领域重要挑战和值得及时探索的方向.本文采用冷冻-解冻制备水凝胶与冷冻干燥技术,设计合成系列以聚乙烯醇和相变微胶囊为骨架的相变气凝胶.此类相变气凝胶同时具有优异的压缩和拉伸性能,能够压缩55%以上或拉伸达25%,突破了气凝胶不可拉伸、相变材料硬脆不可拉伸的特征.比表面积最高达14.4 m2/g,密度和热导率分别低至0.11 g/cm3和0.040 W/(m·K),相变焓可进行调控,最高达到46.1 J/g.进一步的实验证明,相变气凝胶较于热导率更佳的聚乙烯醇气凝胶具有更加优异的温度调控能力,温度维持能力最高可达纯气凝胶的2.6倍.因此相变气凝胶同时具有优异的绝热和调温性能,在微环境调控领域具有重要应用价值.
Personal thermal management is a strategy to energy management of human body and its local environment,which can significantly improve human body thermal comfort and reduce energy consumption on building cooling and heating.Traditional approaches could either self-cooling or thermal insulation,but could hardly fulfill both thermal insulation and cooling in one structure.Thus,it’s still a challenge to design and synthesize materials with dual functions.In this work,phase-change-material aerogels(PCMAs)were designed and synthesized via a sol-gel and freeze drying process,in which PVA and microencapsulating PCM acted as stable skeleton for the porous structures.The PCMAs showed excellent mechanical properties and could be compressed up to 55%or be tensile stressed up to 25%,making them outstanding for traditional aerogels and PCMs.The specific surface areas of the aerogel reached 14.4 m2/g,and extremely low density(0.11 g/cm3)and low thermal conductivity(0.040 W/(m·K))were also achieved.Impressively,the PCMAs exhibited high latent heat up to 46.1 J/g.When the outer temperature was 78℃,the inner temperature protected by PCMA was ca.60℃,which was 18℃lower.On the other hand,when the environment temperature was reduced,the temperature reservation ability of the PCMA was 2.6 times of that of pure PVA aerogel(which possessed lower thermal conductivity of 0.028 W/(m·K)but zero latent heat).The results indicated that the PCMAs had excellent thermal insulation and temperature reservation capacities,suggesting that the PCMAs could be ideal candidates for personal thermal management.
作者
方强
单夏梦
刘玲
胡雪妍
王锦
Qiang Fang;Xia-meng Shan;Ling Liu;Xue-yan Hu;JinWang(Key Laboratory of Multifunctional Nanomaterials and Smart Systems,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123;School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2022年第2期165-173,共9页
Acta Polymerica Sinica
基金
国家重点研发计划项目(项目号2016YFA0203301)
国家自然科学基金(基金号91963124,51773225)资助项目.
关键词
气凝胶
相变材料
多孔材料
聚乙烯醇
Aerogel
Phase change materials
Porous Materials
Poly(vinyl alcohol)
