Yu Xiaoyang, Li Huan, Kang Ning, Lu Shouxiang, Xu Mingjun, Wan Man Pun
State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, 230026, China.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
Adv Sci (Weinh). 2025 Jun 19:e06808. doi: 10.1002/advs.202506808.
Superelastic aerogels with ultralow thermal conductivity have essential advantages for advanced thermal management systems in energy-efficient buildings. However, inorganic aerogels suffer from brittleness and poor processability, whereas their organic counterparts experience high production costs and inadequate elastic recovery. This study used a dual-template (ice and bubble) strategy to fabricate ultralight, superelastic aerogels with hierarchical porosity inspired by stress-dissipating dome architectures. Microbubbles are engineered via a modified "Tessari method" to create macropores (≈100 µm) while ice-templating introduced aligned pores of a few µm in size during freeze-drying. The synergistic interplay of a rigid gelatine (Ge) skeleton, flexible polyvinyl alcohol (PVA) nodes, and potassium salt-enhanced crystalline domains yielded aerogels with exceptional elasticity, ultralow density and thermal conductivity. Flame retardancy is achieved through potassium salt-mediated catalytic carbonization, reducing the peak heat release rate by 54% and enabling self-extinguishing behavior. Microbubble introduction in precursors can provide macropores for aerogels, which dispersed internal stress during the deformation of aerogel, whereas dynamic hydrogen bonds enabled rapid water-assisted self-healing ability and closed-loop recyclability. Scalable production using commercial compressed air foaming systems and a low raw material cost further highlight its industrial viability. Combined with biodegradability and superior thermal insulation, this work advances sustainable, fire-safe aerogels for multifunctional applications.
具有超低热导率的超弹性气凝胶对于节能建筑中的先进热管理系统具有重要优势。然而，无机气凝胶存在脆性和加工性能差的问题，而有机气凝胶则生产成本高且弹性恢复不足。本研究采用双模板（冰和气泡）策略，受应力消散穹顶结构启发，制备了具有分级孔隙率的超轻、超弹性气凝胶。通过改进的“泰萨里方法”设计微气泡以形成大孔（≈100 µm），同时在冷冻干燥过程中冰模板引入了尺寸为几微米的排列孔隙。刚性明胶（Ge）骨架、柔性聚乙烯醇（PVA）节点和钾盐增强的结晶域之间的协同相互作用产生了具有卓越弹性、超低密度和热导率的气凝胶。通过钾盐介导的催化碳化实现阻燃性，将峰值热释放速率降低54%并实现自熄行为。在前体中引入微气泡可为气凝胶提供大孔，其在气凝胶变形过程中分散内部应力，而动态氢键则赋予快速水辅助自修复能力和闭环可回收性。使用商用压缩空气发泡系统进行可扩展生产以及低原料成本进一步突出了其工业可行性。结合生物降解性和卓越的隔热性能，这项工作推动了用于多功能应用的可持续、防火安全气凝胶的发展。
