Effects of precursor concentration on the physicochemical properties of ambient-pressure-dried MTES based aerogels with using pure water as the only solvent

This work presents a facile synthesis approach of methyltriethoxysilane (MTES) based aerogels using pure water as the only solvent, and the effects of precursor concentration on the physicochemical properties are investigated in detail. Therein, the precursor concentration has no effect on the chemical composition but causes the denser and slenderer skeletons at the lower precursor concentration and vice versa. At the 14.4 vol% precursor concentration, the MTES based aerogels are made up of slender skeletons, having the minimum density (0.057 g/cm3), the maximum porosity (97.5%), and the low thermal conductivity (29.4 mW/m/K). It further finds the denser and slenderer silica skeletons cause higher compressive strength and higher Young’s modulus. The TG-DSC results indicate the nice thermal stability of MTES based aerogels. In short, this research demonstrates the great competitive advantages of MTES based aerogels in the field of thermal insulation from the view of preparation method, thermal conductivity, and thermal stability.