Preparation Of Bioinspired Controllable Wetting Hierarchical Materials And Study On Oil-water Separation Performance

In recent years,with the rapid development of large scale industrialization and urbanization process,the discharge of oily wastewater and sewage in daily life has increased dramatically.Untreated oily wastewater will cause considerable economic losses,and also pose a serious threat to the local ecological environment,which will further affect the quality of life and health of human beings.Traditional oil-water separation methods,including adsorption,in-situ combustion,centrifugation,biodegradation and so on,have the inherent disadvantages of low separation efficiency,complex separation process,secondary pollution,high operating costs and so on,which can not meet the needs of large scale oil-water separation.In this study,copper mesh,copper foam and cellulose membrane substrate materials were utilized to prepare special wetting separation materials by various chemical methods to separate miscible and immiscible oil-water mixtures.The main contents of this paper are as follows:The copper mesh was used as the substrate,and the superhydrophobic flower-like Cu₃（PO₄）₂·2H₂O nanosheets were successfully prepared on the surface of the copper mesh by in-situ growth and hydrophobic modification of the silane coupling agent.The prepared materials were characterized by scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）and X-ray diffractometry（XRD）.The prepared material can be used for the separation of oily wastewater,and the average separation efficiency reaches or even exceeds 95%.At the same time,the related mechanism of oil-water separation was studied in detail from the perspective of positive and negative capillary effects.The copper foam is the base,inspired by the hierarchical structure of the lotus leaf,and has hierarchical lotus leaf-like micropapillae structure.The prepared modified copper foam has both superhydrophobic and super hydrophilic surface properties,and can effectively separate various oil-water mixtures.In addition to high separation efficiency,superhydrophobic copper foam has strong antibacterial activity against E.coli and S.aureus.The Janus cellulose membrane with asymmetric wettability and strong antibacterial activity was prepared by simple in situ immobilization and hydrophobic modification using cellulose membrane as the substrate.More importantly,the Janus cellulose membrane exhibited excellent separation performance for both water-in-oil and oil-in-water emulsions,and the separation efficiency was over 96.0%.Besides,both sides of the Janus cellulose membrane showed strong antibacterial activity against both E.coli and S.aureus.