Studies On Preparation And Performance Of The Oleophilic/hydrophobic Coatings On Stainless Steel Mesh

Since the 21 st century,with the rapid development of the world economy and the accelerating process of industrialization,every industry or trade has discharged large amounts of oily sewage in the process of production.Conventional oil-water separation methods have been difficult to meet the requirements for the treatments of oily water.Inspired by super-hydrophobic phenomena on the surface of animals and plants in nature,researchers have been prepared a variety of specific wetting oil-water separation materials used for the treatment and purification of the oily water.Because of its ability to separate oil from oily sewage rapidly and efficiently,the specific wetting oil-water separation materials have become the research hot spot all over the world.In this paper,oleophilic/hydrophobic silica sols are prepared by sol-gel method.Oleophilic/hydrophobic coatings are prepared by dip-coating method on the surface of the stainless steel mesh.In order to get the best hydrophobic properties of the modified filter mesh,the effect of the heat-treat temperature,precursor ratio for preparation of sol and dip-coating times on the hydrophobic properties of the coatings are investigated.The hydrophobicity,surface topography and coating element are characterized and analyzed by optical contact angle(OCA),focused ion beam-scanning electron microscope(SEM),atomic force microscope(AFM),X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectrometer(FTIR).A series of experiments are carried out to test the performance of modified filter mesh.Oleophilicity and hydrophobicity of the filter mesh are investigated through water-holding test and flushing test.Durability of the filter mesh are investigated by ultrasonic cleaning and soaking in the acid and alkali solution.Separation performance are investigated through two oil-water separation methods for different kinds of oil-water mixture.The results show that the modified filter mesh has showed goodoleophilic/hydrophobic properties and it can maintain the performance well under ultrasonic cleaning condition as well as soaking in solution of pH=3-11.Oil and water separation experiments show that the modified filter mesh has good separation efficiency and reusable performance.The separation efficiencies of the two separation methods for different kinds of oil-water mixtures are both above 90%.