Superhyrophilic and superoleophobic coating for separation oil/water mixture

The main objective of this project is preparing coatings with different wettability of water and oil on the 304 stainless steel mesh, for achieving phase separation . PDMS-NH2 resin and Perfluorooctanoic acid were used for achieving hydrophilicity and superoleophobicity, respectively. Dibutyltin dilaurate was added as a hardener and silica nanoparticles have been used to make the surface rough. The contact and slip angle measurements, Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR) characterization were done on samples. Different concentrations of SiO2 nanoparticles were evaluated and ultimately 10 g/l silica nanoparticles were chosen as the optimal concentration. It was observed that in order to achieve the simultaneous superoleophobicity and hydrophilicity, the concentration of 1 g/l PDMS- NH2 should be chosen. Different amounts of superoleophobic component in the range of 300-900 ml/l were added to the solution and it was observed the optimal amount needed to react with a hydrophilic polymer was 200 m/l PFONa. After achieving a coating with different wettability of water and oil (oil contact angle= 144o and water contact angle =0o), an oil and water separation system with high separation efficiency of 96% was designed.

Keywords:

superhydrophilic , superoleophobic , stainless steel mesh , silica nanoparticle , separation of oil and water