Preparation And Mechanism Of PH-Responsive Wetting Iron Foam Bionic Surface

With the continuous development of society,the discharge of industrial oil-bearing effluent and catering oil-bearing effluent is increasing.The random discharge of oil-bearing effluent will cause serious environmental pollution.With the increase of crude oil production,the frequent occurrence of offshore oil leakage accidents will damage the marine environment and waste energy.Inspired by nature,bionic surface with special wettability has become a research hotspot for oil-water treatment.The prepared special wettability interface material has superhydrophobic,self-cleaning,antifouling,corrosion resistance and other properties,and has effective oil-water separation performance.Compared with the super-wetting material,the traditional oil-water separation technology has lower separation efficiency and stability.In this paper,porous iron foam was used as substrate,and micro nano structure was prepared on the surface of iron foam by electrodeposition.Then the pH responsive smart wetting surface was prepared by mixing different thiols.The micro nano structure on the surface of iron foam was prepared by electrodeposition,and the surface of low molecular weight superhydrophobic surface was prepared by modifying the surface with 1-Dodecanethiol.The effects of electrodeposition time,voltage and electrolyte parameters on the surface morphology and wettability of the samples were systematically analyzed by designing different process parameters.When the DC voltage is 2V,the power on time is 105min,and the electrolyte concentration is 0.6mM AgNO₃?1.6mM SDS?0.6mM KNO₃,it is the best process parameter to prepare the low adhesion superhydrophobic surface.The contact angle of the sample surface is 152.6°,the rolling angle is 6°,and the surface is self-cleaning.Based on its superhydrophobicity and superhydrophilicity,the oil-water mixture solution,such as tetrachloromethane/water,can be separated.The separation efficiency is more than 98.5%,and it has good recycling performance.Based on the above electrodeposition parameters,the micro nano structure was deposited on the surface of the iron foam,and the surface of 11-Mercaptoundecanoic acid and 1-Dodecanethiol mixed with mercaptan was further modified to prepare the wetting surface with pH response.The phase transformation between super hydrophobic and super hydrophilic can be achieved under pH control.By changing the pH value of the solution,a variety of oil/water mixtures can be selectively separated.In the solution environment with pH=7,heavy oil/water oil-water mixture solutions such as chloroform and dichloromethane can be separated.The oil drops penetrate through the surface and the water is blocked.When the pH value of water is 13,the water passes through the iron foam and is collected.The separation efficiency of oil and water mixture with different gravity is as high as 99.5%,which has a good separation efficiency.At the same time,the sample has wear resistance and thermal stability?¹70??.Therefore,the smart surface with changeable wettability can be a good choice for oil-water separation under different modes,and it is expected to provide a new solution for the treatment of oily effluent and increasingly serious oil leakage.