A flexible biomimetic superhydrophobic and superoleophilic 3D macroporous polymer-based robust network for the efficient separation of oil-contaminated water

Abstract

The development of stable 3D surfaces for oil/water separation has been of great interest to researchers. Inspired by the lotus leaf, in this study, a superhydrophobic stable and robust surface was generated by the combination of n-octadecyltrichlorosilane, silica, polypyrrole and polyurethane (ODTCS–SiO₂–PP–PU). The constructed 3D network displayed superhydrophobic and superoleophilic behavior with a high water contact angle of 154.7° ± 0.8°. The superhydrophobic behavior of the porous material was found to be stable for months. Apart from the hydrophobicity analysis of the material, the various forms of the materials were investigated via scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDX). Under the force of gravity, hexane displayed an exceptionally high flux of 102 068 Lm⁻² h⁻¹ through ODTCS–SiO₂–PP–PU. The macroporous network of ODTCS–SiO₂–PP–PU displayed fewer chances of fouling, which is a common issue with membranes. Moreover, its porous network displayed good absorption capacity for various non-polar organic solvents. The maximum absorption capacity observed for toluene was 34 times its own weight. The separation efficiency of various non-polar organic solvents from water was observed in the range of 99.5 to 99.8%. ODTCS–SiO₂–PP–PU, due to its superhydrophobicity, 3D porous network, extraordinarily high flux, good absorption capacity, and excellent separation capability, has been established as a good candidate for the separation of organic and oil contaminants from water.