Macias Carlos, Rasines Gloria, García Tomas E, Zafra María C, Lavela Pedro, Tirado José L, Ania Conchi O
I + D Department, Nanoquimia S.L., 14014 Córdoba, Spain.
Campus Universitario, IUTA, Universidad de Oviedo, 33203 Gijón, Spain.
Gels. 2016 Jan 15;2(1):4. doi: 10.3390/gels2010004.
We report the synthesis of conductive and mechanically compliant monolithic carbon aerogels prepared by sol-gel polycondensation of melamine-resorcinol-formaldehyde (MRF) mixtures by incorporating diatomite and carbon black additives. The resulting aerogels composites displayed a well-developed porous structure, confirming that the polymerization of the precursors is not impeded in the presence of either additive. The aerogels retained the porous structure after etching off the siliceous additive, indicating adequate cross-linking of the MRF reactants. However, the presence of diatomite caused a significant fall in the pore volumes, accompanied by coarsening of the average pore size (predominance of large mesopores and macropores). The diatomite also prevented structural shrinkage and deformation of the as-prepared monoliths upon densification by carbonization, even after removal of the siliceous framework. The rigid pristine aerogels became more flexible upon incorporation of the diatomite, favoring implementation of binderless monolithic aerogel electrodes.
我们报告了通过三聚氰胺 - 间苯二酚 - 甲醛（MRF）混合物的溶胶 - 凝胶缩聚反应，加入硅藻土和炭黑添加剂制备出具有导电性和机械柔顺性的整体式碳气凝胶。所得的气凝胶复合材料呈现出发达的多孔结构，证实了在前体聚合过程中，任何一种添加剂的存在都不会阻碍聚合反应。在蚀刻掉硅质添加剂后，气凝胶保留了多孔结构，这表明MRF反应物有足够的交联。然而，硅藻土的存在导致孔体积显著下降，同时伴随着平均孔径的增大（大介孔和大孔占主导）。即使在去除硅质骨架后，硅藻土也能防止所制备的整体材料在碳化致密化过程中发生结构收缩和变形。加入硅藻土后，刚性的原始气凝胶变得更加柔韧，有利于实现无粘结剂的整体式气凝胶电极。
