Facile synthesis of ternary flexible silica aerogels with coarsened skeleton for oil–water separation

Abstract

Ternary flexible silica aerogels were synthesized using a facile sol-gel process without solvent exchange and surface modification using dimethyldiethoxysilane (DEDMS), methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) <i>via</i> ambient pressure drying. The skeleton morphology of the aerogels was precisely controlled by the DEDMS/TEOS molar ratio (D). The effect of the morphology of the aerogel skeleton on the mechanical properties and the adsorption capacity was investigated. As the D increased, the morphology of the aerogel skeleton gradually changed from a fragment structure to a coarsened structure, and finally to a chain-like structure. The prepared coarsened structure aerogel exhibited a low density of 0.095 g cm^-3, a compressible amount reaching up to 78.2%, a Young's modulus as low as 14 kPa, a superhydrophobicity with a contact angle of 154.8° and an excellent adsorption capacity of 8.7-15.4 g g^-1. Furthermore, the outstanding recycling ability and corrosion resistance made the aerogels suitable for oil-water separation in corrosive environments.