Bionic Preparation Of Special Wettability Materials And Its Application In Oil/water Separation

With the development of the industrialization of the petroleum industry and manufacturing industry,the occurrence of marine oil spills and the discharge of oily sewage have seriously affected our water resources and ecological environment.However,bionic preparation of superwettability materials play a vital role in the treatment of oil and water pollution,due to their special wetting properties.The filtration-based and absorption-based superhydrophobic/superoleophilic materials were prepared for oil/water separation in this work,which include bionic construction of micro-nano structures and hydrophobically modified artificial sponge on the surface of the materials.In this work,green,non-toxic,durable,highly elastic,and chemically stable oil/water separation materials was prepared.Meanwhile,an oil-water separation device was designed for continuous in-situ adsorption.The main contents are as follows:(1)We have successfully prepared superhydrophobic surfaces,which were synthesized by using the polydimethylsiloxane(PDMS)as adhesive and the magnesium palmitate(Mg-P)were evently coated to form roughness on the surfaces of glass,textile,stainless steel mesh,and fluting paper.The as-fabricated superhydrophobic surfaces possessed excellent water-resistance,self-cleaning properties,durability,and robustness.In the actual oil/water separation,the water contact angle and oil collection efficiency of the superhydrophobic mesh were still more than 150° and 91% even after separation over 10 cycles,respectively.(2)A three-dimensional,elastic,super-hydrophilic Ag-PVAs composite sponge was successfully prepared by hydrothermal method,and then modified by carbonization method to obtain a superhydrophobic carbon sponge.The average diameter of the fibers decreased from 1.25 ?m to nearly 500 nm in the sponge,when the annealing temperature was increased.The water contact angle of carbon sponge were 153°,158°,and 164°,when the annealing temperature were 500 °C,600 °C,and 700 °C,respectively.At the same time,the rolling angles were less than 10°,showing superhydrophobicity.Subsequently,a carbon sponge at 500 °C was used for oil/water separation experiments.It was found that the adsorption capacity of sponge could reached 58 times its own weight,indicating its good recyclability.(3)The Ag-PVAs sponge was modified with low surface energy polydimethylsiloxane(PDMS)to reduce its surface energy and improve its mechanical properties.The water contact angle of the f-PDMS composite sponge could reached 156° after modified with PDMS,indicating excellent superhydrophobicity.Importantly,the maximum stress of f-PDMS sponge could reach more than 14 times that of Ag-PVAs sponge under 80% strain because of role of PDMS.Meanwhile,the maximum compressive stress of the f-PDMS sponge can still be maintained at 87.3% after 50 stress-strain cycles at 70% strain.Moreover,based on its excellent stress-strain performance,the vacuum-assisted suction filtration device was designed to achieve continuous in-situ adsorption of oil in the study.