A novel superhydrophilic/superoleophobic nanocomposite PDMS-NH2/PFONa-SiO2 coated-mesh for the highly efficient and durable separation of oil and water

A surface to separate oil–water mixtures is a global concern and highly needed particularly in oil industries. The present study was conducted to create a novel superhydrophilic/superoleophobic nanocomposite coating on the stainless-steel mesh for the aim of oil/water separation. Different hydrophilic resins along with PFOA as oleophobic agent with 15 flours in its chemical structure and various oxide nanoparticles containing SiO2 and TiO2 at different concentrations were studied to achieve superhydrophilic/superoleophobic surface. The fabricated nanocomposites were fully characterized via field-emission scanning microscopy (FESEM), atomic force microscopy (AFM) and Fourier-transform infrared spectroscopy (FTIR). At the optimum concentration of resin and oxide nanoparticles, oil contact angle (OCA) and water contact angle (WCA) of 144° and 0° were achieved, respectively. The plausible mechanism of superhydrophilic/superoleophobic behavior of the coating is mainly associated with the micro-nano hierarchical structure of the coating owing to boosted roughness caused by the presence of SiO2 nanoparticles and their effective embedding into hydrophilic resin PDMS-NH2 and using metallic mesh substrate besides the reduced surface tension due to the using PFONa, strong bonding of the film to the substrate. Ultimately excellent oil/water separation efficiency of 96 ± 1% with high stability was attained.