Highly efficient Oil/Water and brine Separations: Superhydrophobic hybrid isobornyl methacrylate coatings

A rapid and facile method to obtain a fluorine-free, superhydrophobic/superoleophilic coating with superior thermal stability based on a cyclic methacrylate chemistry is reported. The chemical structure of the coating is based on the crosslinking reaction of isobornyl methacrylate, ethylene glycol dimethacrylate (crosslinker) and a 3-(trimethoxysilyl)propyl methacrylate (adhesive), using AIBN as initiator, toluene as solvent, and silica nano particles. Chemorheology results showed that the coating can be fully cured in 10 min at 100 degrees C, exhibiting a water contact angle (CA) of 165 +/- 3 degrees, and an oil CA of 0 degrees for eight oils of wide commercial interest (gasoline, diesel, petroleum ether, kerosene, hexane, toluene, chloroform and dichloromethane). The superhydrophobic/superoleophilic exhibited nanostructures and multiscale roughness throughout the surface, and excellent adhesion properties on the mesh screen. Also, the coating exhibited outstanding oil/water separation efficiency (>99 %) for all eight types of oil/water mixtures studied, as well as for hexane/saturated brines of NaCl, KCl or MgSO4, besides having high recyclability. Isothermal and non-isothermal TGA revealed its high thermal stability, and the activation energy of thermal degradation according to the Kissinger and modified Ozawa models were 115.6 and 119.2 kJ/mol, respectively.