The Study On The Fabrication Of Superhydrophobic Mesh For Oil/Water Separation

In recent years,the special wettability of superhydrophobic materials has attracted wide attention.The unique functions of superhydrophobic materials in oil/water separation and self-cleaning performance make them widely applied in daily life and scientific research.In this paper,superhydrophobic stainless steel mesh was prepared by covalent layer-by-layer grafting method and in-situ thermal polymerization method.Its structure,principle,application and durability were studied in detail.The main contents are as follows.Superhydrophobic stainless steel mesh was prepared by covalent layer-by-layer grafting method in four steps of hydroxylation,silylation,interfacial polymerization and grafting of long-carbon chain.The result indicated that the as-prepared mesh had a micro/nano rough surface as well as an excellent superhydrophobicity with water contact angle of 159°.Besides,the mesh showed self-cleaning effect with a low sliding angle of 4°.As for application evaluation,the mesh could act as a filter for the highly efficient separation of a series of oil/water mixtures.The water intrusion pressure was measured to be 3.58±0.05 kPa,which is relatively high compared to the earlier reports.Through comparison experiments,it was verified that as-prepared mesh possesses excellent stability,which is due to the strong interaction of chemical bonds between multi-polymer layers.In addition,the mesh exhibited excellent stability in the case of ultrasonic vibration environment,long-term storage and corrosion environment.Superhydrophobic stainless steel mesh was prepared by in-situ thermal polymerization method.The superhydrophobic surface was prepared by one-step process under the specific reaction conditions through the mixed solution of precursor monomer DDVAC and silica nanoparticles.The DDVAC-O polymer was prepared in the oxygen environment for the first time.An“oxidative crosslinking”effect was found,and the possible mechanism was proposed.The groups in the proposed mechanism were verified by means of XPS,FT-IR and Solid-state ¹³C NMR analyses.The as-prepared exhibited superhydrophobicity with water contact angle of 158°.Besides,the mesh showed self-cleaning effect with a low sliding angle.As for oil/water separation application,the as-prepared mesh exhibited its high intrusion pressure and oil flux.In the aerobic thermal polymerization process,DDVAC monomer could form the highly cross-linked polymer DDVAC-O and tightly wound cover on the mesh surface.Thus,the mesh exhibited excellent stability and durability toward ultrasonic,abrasion treatment,long-term storage,and even under strongly acidic,alkaline,and saline environment conditions.In summary,this kind of superhydrophobic mesh can be a good candidate in the actual process of oil/water separation.