Nano-Engineering Silica Aerogel Structure to Determine the Property-Structure Relationship

Abstract

We characterize mechanically strong nano/meso-porous cross-linked templated silica aerogels that were synthesized through the sol gel process and reinforced by nano casting a 4–10nm thick conformal layer of isocynate derived polymer. Tri-block co-polymer (pluronic P123) was used as a structure directing agent to produce ordered mesoporous walls while 1, 3, 5 trimethylbenzene (TMB) was added as micelle-swelling reagent to regulate the size of the pores. The shape and size of the micro and meso pores were nano engineered by varying the amount of chemical surfactant as well as the concentration of the cross-linking solution used to form the polymer nano layer. In so doing we manipulated the structure at the molecular level to develop an optimized structure that closely resembles the honeycomb structure found in nature. Dynamic mechanical analysis (DMA) test results established that the material had an α-grass transition temperature of about 130°C while quasi-static compression tests showed that the optimized nano-structured silica aerogel had a Young’s modulus of about 800MPa. We present the synthesis protocol as well as chemical, physical and mechanical characterization of cross-linked templated silica aerogel (CTSA). ). In addition, material point method (MPM) simulation results are highlighted.