Rapid synthesis and characterization of monolithic ambient pressure dried MTMS aerogels in pure water

In this work, monolithic silica aerogels were prepared in pure water within 4 h by using MTMS as the precursor under ambient pressure drying (APD). The effects of the volume ratio of H2O/MTMS, CTAB content and NH3·H2O concentration on the properties of MTMS-based aerogels (MSA) were investigated experimentally. The realization of the rapid synthesis of MSA under APD is attributed to getting rid of the aging process, solvent exchange and surface modification. It demonstrates that the microstructure of MSA is comprised of coralloid branches. Furthermore, the greater volume ratio of H2O /MTMS, larger CTAB content and smaller NH3·H2O concentration cause relatively slimmer coralloid branches, smaller pores and weakened connectivity of skeletons. It also finds that the MSA with a greater volume ratio of H2O/MTMS presents larger Young’s modulus and smaller compressive stress, which is because of the correspondingly different microstructures. The as-prepared MSA shows a low density of 0.064 g/cm3 and a contact angle as high as 143.4°, which provides their potentials for some engineering applications.