Ji Yongyi, Chen Zibo, Si Yunfa, Tanwei Mingyang, Wang Sichang, Cao Shaowen, Liu Bo, Wu Geng, He Daping
Sanya Science and Education Innovation Park of Wuhan University of Technology, Sanya, 572000, China.
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China.
Small. 2025 Aug;21(33):e2503979. doi: 10.1002/smll.202503979. Epub 2025 Jun 23.
3D porous ordered aerogels attract considerable attention in catalysis, energy storage, and biomedical engineering, yet the precise construction of aerogels' microstructures remains challenging. Herein, inspired by secondary dendrite formation in metal casting, a programmable assembly strategy is reported to customize 3D hierarchical ordered aerogels through freeze casting with internal cold fingers (ICF). As revealed by the temperature field and phase-transition simulations, the ICF effectively regulates the temperature gradient, which subsequently controls the nucleation process, and growth orientation of ice crystals during the solidification of the ice template. As a result, programmable regulation of the porous graphene oxide aerogels is attained. Benefiting from the hierarchical ordered structures, 3D porous ordered reduced graphene oxide aerogels exhibit significant heat dissipation enhancement in microelectronic devices than conventional freeze casting aerogels'. Furthermore, the freeze casting employing the ICF strategy provides a universal strategy to construct programmable 3D porous aerogels of MXene nanosheets, h-BN nanosheets and carboxymethyl cellulose nanowires.
三维多孔有序气凝胶在催化、储能和生物医学工程领域备受关注，然而气凝胶微观结构的精确构建仍然具有挑战性。在此，受金属铸造中二次枝晶形成的启发，报道了一种可编程组装策略，通过带有内部冷指（ICF）的冷冻铸造来定制三维分级有序气凝胶。温度场和相变模拟表明，ICF有效地调节了温度梯度，进而控制了冰模板凝固过程中冰晶的成核过程和生长取向。结果，实现了对多孔氧化石墨烯气凝胶的可编程调控。受益于分级有序结构，三维多孔有序还原氧化石墨烯气凝胶在微电子器件中比传统冷冻铸造气凝胶表现出显著的散热增强。此外，采用ICF策略的冷冻铸造为构建MXene纳米片、h-BN纳米片和羧甲基纤维素纳米线的可编程三维多孔气凝胶提供了一种通用策略。
