Abstract：
Atmospheric drying method for fabricating aerogels is considered the most promising way for casting aerogels on a large scale. However, the organic solvent exchange, remaining environmental pollution risk, is a crucial step in mitigating the impact of surface tension during the atmospheric drying process, especially for wet gel formed through the alkoxy-derived sol-gel process, such as melamine-formaldehyde resin (MF) aerogel. Herein, a tough polymer-assisted in situ polymerization was proposed to fabricate MF resin aerogel with a combination of mechanical toughness and strength, enabling it to withstand the capillary force during water evaporation. The monolithic MF resin aerogel through the sol-gel method can be directly prepared without additional network strengthening or organic solvent exchange. The resulting MF resin aerogel exhibits a homogeneous as well as hierarchical structure with macropores and mesopores (~6 μm and ~5 nm), high compressive modulus of 31.8 MPa, self-extinguishing property, and high-temperature thermal insulation with 97 % heat decrease for butane flame combustion. This work presents a straightforward and environmentally friendly method for fabricating MF resin aerogels with nanostructures and excellent performance in open conditions, exhibiting various applications.
摘要：
用于制造气凝胶的大气干燥方法被认为是大规模铸造气凝胶的最有希望的方法。然而,有机溶剂交换，剩余的环境污染风险，是减轻大气干燥过程中表面张力影响的关键步骤，特别是对于通过烷氧基衍生的溶胶-凝胶过程形成的湿凝胶，如三聚氰胺-甲醛树脂(MF)气凝胶。在这里，提出了一种坚韧的聚合物辅助原位聚合制备具有机械韧性和强度相结合的MF树脂气凝胶，使其能够承受水蒸发过程中的毛细力。通过溶胶-凝胶法可以直接制备整体式MF树脂气凝胶，而无需额外的网络增强或有机溶剂交换。所得MF树脂气凝胶具有大孔和中孔（〜6μm和〜5nm）的均匀和分层结构，31.8MPa的高压缩模量，自熄性,丁烷火焰燃烧的热减少97％的高温隔热。这项工作提出了一种简单而环保的方法，用于制造具有纳米结构和在开放条件下优异性能的MF树脂气凝胶，展示各种应用。
