Compressible, Thermally Insulating, and Fire Retardant Aerogels through Self-Assembling Silk Fibroin Biopolymers Inside a Silica Structure—An Approach towards 3D Printing of Aerogels

摘要: Thanks to the exceptional materials properties of silica aerogels, this fascinating highly porous material has found high-performance and real-life applications in various modern industries. However, a requirement for broadening these is based on further improvement aerogel properties, especially with regard mechanical strength postsynthesis processability minimum compromise other physical properties. Here, we report an entirely novel, simple, aqueous-based synthesis approach prepare mechanically robust hybrids by cogelation silk fibroin (SF) biopolymer extracted from silkworm cocoons. The sequential processes acid catalyzed (physical) cross-linking SF simultaneous polycondensation tetramethylorthosilicate (TMOS) presence 5-(trimethoxysilyl)pentanoic (TMSPA) as coupling agent subsequent solvent exchange supercritical drying. Extensive characterization solid-state 1H NMR, 29Si 2D 1H-29Si heteronuclear correlation (HETCOR) MAS NMR spectroscopy well microscopic techniques (SEM, TEM) assessment confirmed molecular-level homogeneity hybrid nanostructure. developed silica-SF contained improved set such low density (ρb,average = 0.11-0.2 g cm-3), high porosity (∼90%), specific surface area (∼400-800 m2 g-1), excellent flexibility compression (up 80% strain) three orders magnitude Young's modulus over that pristine aerogels. In addition, aerogels are fire retardant demonstrated thermal insulation performance conductivities (λ) 0.033-0.039 W m-1 K-1. As advantage, formulated showed printability wet state using microextrusion-based 3D printing approach. printed structures had comparable their monolith counterparts, improving processing or shaping significantly. Finally, reported here represent significant progress customized multipurpose applications, namely, dual open-cell biomaterial used regenerative medicine.