Preparation Of Superhydrophobic/Superamphiphoic Coating Based On Silicone Combustion Product By Spraying

Over the last few decades,wettability has received much attention in the academic research of colloidal interfaces and industrial fields.Among them,superhydrophobic and superamphiphobic materials are the most attractive due to their applications in anti-icing,anti-corrosion,anti-adhesion,drag reduction,microfluidic control,oil-water separation,heat transfer and so on.With the increasing demand and production of silicone materials in industry,the scrap and discarded silicone products produced in daily life and scientific research are increasing rapidly.Due to the lack of appropriate recycling methods,the problems of environmental pollution and waste of raw materials of silicone are extremely urgent.In this paper,the superhydrophobic/superamphiphobic coating was prepared via spraying the SiO2 aggregates by calcination of discarded silicone,the method is very simple and the cost is low,which opens up new ideas for solving the environmental pollution and the waste of raw materials,and has a broad prospect in large-scale industrial production and domestic use.The main research contents are as follows:(1)With high-temperature calcination,the epoxy silane generated by the degradation reaction of the silicone rubber is further oxidized to form SiO2 nanoparticles of several tens to several hundreds of nanometers.Silica particles of different sizes are deposited into clusters by physical vapor deposition to form a porous micro-nano structure.The ideal sintering parameters of silicone rubber are calcination temperature of 800?,calcination time of 3?4 h,and heating rate of 5?/min.The porous micro-nano structure of the silica aggregates produced after calcination according to this parameter can lock a large amount of air,and the the surface wetbility is excellent after fluorination.The impurities in the silicone rubber tube have little effect on the morphology of the silica aggregate,and the residue is a dense silica ceramic.(2)The spraying method is directly sprayed the coatings on a substrate to obtain a superhydrophobic/superamphiphobic surface.The method is very simple and not subject to the shape of the substrate.The tetrahydrofuran was selected as the solvent,and the mixture of SiO2 and PDMS dissolved in the solvent was sprayed to prepare a stable superhydrophobic SiO2/PDMS composite surface.When the mass ratio of SiO2 to PDMS is 2:1,the composite coating displays excellent hydrophobicity and stability.The surface still able to maintain good hydrophobicity after repeated stripping tests.When anhydrous ethanol is selected as the solvent,the superhydrophobic/superamphiphobic coating is excellent in transparency,the contact angle is more than 150°,the rolling angle is less than 1°,the coating maintained its superamphiphobic properties even after flushing of the coating with water for several hours or the trespass of over thousands of water drops with a faster velocity and a larger radius.(3)The separation net prepared by spraying the modified silica aggregates onto the stainless steel mesh substrate can effectively separate a plurality of oil-water mixed liquids,the separation efficiency is above 90%,and the recycling property is excellent.