Study On Preparation Of Fe/Co/Ni Metal Oxide Superhydrophobicfilms And Their Application In Oil/water Separation

In recent years,because of the frequent occurrence of water pollution which is caused by oil spillage,oil/water separation becomes inereasingly topical.Conventional methods,including gravity separation,flocculation,skimmers,combustion and absorption materials,have many shortcomings such as low separation efficiency and secondary pollution.Therefore,it is necessary to develop a efficient and eco-friendly method to solve this problem.Basing on the observation of the hydrophobic surface in the nature,the superhydrophobic and superoleophilic materials is a recycled material which can separate oil from oil/water mixture selectivity and efficiency.This paper applys nicke foam and sponge as the substrate,to establish the superhydrophobic and superoleophilic surface through three simple synthesis methods（in situ growth method,solution immersion method and hydrothermal method）.The oil/water separation performance of the superhydrophobic and superoleophilic materials text by a simple oil-water separation experiment.The films on Ni foam substrate with nanowire structure were successfully constructed by a simple template-free,ammonia-evaporation-induced method.The films were composed of the mixture of Co（OH）₂ and Co₃O₄ nanowire structure.Then the film was modified with fluoroalkylsilane（FAS）.The water contact angle of the as-prepared Ni foam surface was approximately 156°.The as-prepared Ni foam showed an excellent separation efficiency for different organic solvents and water mixture,more than 97%,through a simple separating unit.Although the separation efficiency of the Ni foam sample show a slight decline after recycle separate 10 times,but remains a high separation efficiency.Therefore,the as-prepared nickel foam is an excellent candidate materials for oil/water separation.The Ni（OH）₂ films with multilevel nano flake structure on sponge substrate were successfully builded via a simple solution immersion method,and then fabricated a superhydrophobic film on it with octadecanoic acid（stearic acid,SA）.This paper also investigated the influence of the experimental conditions on hydrophobicity of the films.The water contact angle of the sponge sample surface was approximately 153°.Oil/water separation process is mainly using the as-prepared sponge to absorb oil and organic solvents in the mixture of water and oil.The as-prepared sponge shows a high absorption capacity.The absorbed oil and organic solvent can be recycled after a simple mechanical compression on sponge.The as-prepared sponge showed well cycle property after repeated absorbed 8 times,the absorbing capacity of oil more than 44 times their own weight.The FeOOH films with nanowire structure on sponge surface were successfully fabricated by a conventional hydrothermal synthesis method,followed by stearic acid modified on the surface to obtain superhydrophobic film.After compared the hydrophobicity of the Fe OOH films which prepared under different reaction conditions shows that when the reaction temperature was 100oC and the reaction time was 4h,the as-prepared sponge reveal better hydrophobicity,which the water contact angle of it was almost 156°.The separation efficiency and recycling of the superhydrophobic sponge was also investigated in this page.The experimental results shows that the sponge samples possess high absorbing capacity of different organic solvents.The as-prepared sponge also showed well cycle property after repeated absorbed 8 times,the absorbing capacity of oil more than 43 times their own weight.