Facile synthesis of sponge reinforced monolithic silica aerogels with improved mechanical property and excellent absorptivity

• Large scale and monolithic sponge reinforced silica aerogels were prepared under ambient pressure.
• The mechanical properties of as-prepared aerogels improved significantly.
• Its absorption capacity of organic liquids is larger than those of pure silica aerogels.

Silica aerogels (SA) with low density were reinforced with monolithic polyurethane sponge (PUS) using the sol–gel method at ambient pressure. The product (PUS reinforced SA) presents good features of high hydrophobicity and lipophilicity after the surface is modified by trimethylchlorosilane (TMCS). In the product, the nanoporous SA granules were held by the PUS skeleton. The SA has excellent absorptivity for various solvents and oils. Moreover, the aerogels demonstrate remarkable elasticity which overcomes the fragility of pure SA without PUS. Furthermore, the preparation process is also cost effective hence the PUS reinforced SA could be recommended as solvent/oil absorbent for the water pollution industry.