Superhydrophobic and Compressible Silica-polyHIPE Covalently Bonded Porous Networks via Emulsion Templating for Oil Spill Cleanup and Recovery.

We synthesize porous polyHIPE networks with silanol functionalities in the polyHIPE backbone. These silanol functionalities are used for covalent bonding with silica aerogels embedded in the polyHIPE. Covalent bonding between silica and polyHIPE networks are confirmed using Fourier-transform infrared spectroscopy and scanning electron microscopy. Silica aerogels covalently bonded with polyHIPE network show macroporous and mesoporous morphologies and possess excellent properties like high bendability, high elasticity, superhydrophobicity (160°), low density (0.128 g/cm), and low thermal conductivity (~0.045 W/m·K). Oil absorption from water/oil mixtures and recovery of the absorbed oil (by squeezing) from flexible silica-polyHIPE networks is studied. The silica-polyHIPE is shown to absorb crude oil ~16-times its own weight and can be reused multiple times after recovery. Hence, such materials are very important for oil spill cleanup applications from aqueous systems.