Facile Preparation of Nanoporous Graphene Oxide/Polydimethylsiloxane-Coated Polyurethane Foam for Efficient, Selective and Repeatable Oil Spill Cleanup

In the present study, graphene oxide (GO) was dip-coated on polyurethane (PU) foam architectures using hydrophobic polydimethylsiloxane (PDMS) as an adhesive. The application of the as-prepared superhydrophobic/oleophilic absorbent (SHOA-1) foam in the absorptive decontamination of oily water was carefully investigated. Fourier Transform Infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and water contact angle measurement were used to characterize the structure and surface properties of the foam samples. The SHOA-1 hybrid foam demonstrated high absorption capacity in oils and organic solvents, with values ranging from 33.65 to 68.30 times its own weight. Furthermore, the as-prepared absorbent showed excellent oil/water selectivity with separation efficiency above 95%. The reusability performance of the material was also evaluated, and the results show only a negligible decrease in the absorption capacity after 10 absorption-squeezing cycles. Moreover, kinetic study reveals that the limiting factor of the sorption process using SHOA-1 foam may be a diffusion phenomenon, synergistically influenced by the foam’s microporous structure (porosity, pore size, and connectivity), sorbent-sorbate interaction (hydrophobicity) as well as the intrinsic properties (viscosity) of the test oil or organic solvent, including their concentration gradient. Therefore, the high-performance, cost-effective, highly durable hybrid material is a promising and beneficial alternative in large-scale oil spill clean-up.