Biomimetic Preparation Of Super-hydrophobic Porous Materials And Application Of Oil-water Separation

With the rapid development of industry and economy,it will bring a lot of convenience to people's life,but also produce some problems of environmental pollution.For example,the discharge of oily wastewater in industry and life has seriously affected the natural environment and human life in recent years.In addition,the phenomenon of oil spills is also emerging,which is not only a waste of resources,but also a threat to the ecological environment.Therefore,how to achieve effective methods for oil/water separation becomes an urgent problem to be solved.Traditional methods for oil/water separation include chemical,physical and biological methods,etc.Although these methods can achieve the effect of oil/water separation,there are still problems such as low separation efficiency,secondary pollution,complicated operation,and high cost.In this paper,superhydrophobic materials are prepared by using cheap and easily available sponge,cotton cloth and stainless steel mesh as substrates.The main contents are as follows:(1)Superhydrophobic sponge was constructed by one step immersion of melamine formaldehyde(MF)sponge into a solution containing dopamine(DA)and dodecyltrimethoxysilane(DTMS).The contact angle of the superhydrophobic sponge is 157.8±0.5°for water and 0°for oil,exhibiting unique superhydrophobic properties.The chemical stability,environmental stability and mechanical stability of the superhydrophobic sponge were studied and it was found that the superhydrophobic sponge can still exhibit good superhydrophobicity after different organic solvents,different pH values,different temperatures and external forces.(2)Superhydrophobic materials are used for oil/water separation.The method of preparing superhydrophobic sponge by one step method has wide applicability,it can modify different substrates including polyurethane sponge,cotton cloth,glass fiber cloth and stainless steel mesh,and eventually a variety of superhydrophobic materials are obtained.The prepared superhydrophobic MF sponge and superhydrophobic cotton cloth can be used in the separation of oil and water mixtures,the oil absorption property of superhydrophobic materials is improved obviously,and the superhydrophobic property can be maintained after several cycles of oil absorption.Similarly,the superhydrophobic stainless steel mesh can also be used for the separation of multi-oil/water mixtures.The separation efficiency is as high as 97.5%,and the superhydrophobic properties can be shown after repeated cycles of oil/water separation.(3)Using a stainless steel mesh as a substrate,polydopamine and titanium dioxide are first attached to a stainless steel mesh by a solvothermal reaction method,and then immersed in a solution containing a low surface energy material to prepare a photocatalytic and superhydrophobic stainless steel mesh.The stability testing of the prepared superhydrophobic stainless steel mesh,degradation of organic pollutants and oil/water separation research,found that the material can be applied in oil/water separation and degradation of dyes.(4)Porous carbon sponge was prepared by carbonization at high temperature using melamine formaldehyde(MF)as the precursor of carbon source.and then magnetic particles was attached to the surface of carbonated sponge by solvothermal reaction,forming rough structure on the surface.Finally,the superhydrophobic sponge with magnetic response was prepared by the introduction of low surface energy substance containing fluorine by the method of vapor deposition.The stability of magnetic superhydrophobic sponge in different environments was studied and it was found that the sponge had good stability.It can be used to separate oil/water mixtures,and it can achieve good superhydrophobicity after several cycles.