Organic–inorganic hybridization for the synthesis of robust in situ hydrophobic polypropylsilsesquioxane aerogels with fast oil absorption properties

In situ hydrophobic polypropylsilsesquioxane aerogels (PSAs) were successfully synthesized via an organic–inorganic hybridization method by a sol–gel process, in which propyltriethoxysilane (PTES) and tetraethylorthosilicate (TEOS) were used as co-precursors. 29Si NMR and FTIR analyses indicated the high degree of condensation of the precursors and proved the attachment of propyl (–C3H7) groups in PSAs, respectively. By means of incorporating propyl groups, both mechanical robustness and in situ hydrophobicity were obtained. Meanwhile, the mechanical strength, contact angle and density obviously increased with the increase in propyl groups. Under optimized conditions, as-prepared PSA could endure up to a 70% maximum linear compression with few cracks. Benefiting from the robust structure and in situ hydrophobicity, PSAs showed high absorption capacities (8–10 times that of its own weight) and fast absorption properties (<20 s) for a wide range of organic solvents and could be reused at least 5 times.