Preparation And Oil-Water Separation Of Hydrophobic Schiff Base Imine Polymer Nanomaterials

Oil-contaminated wastewater poses a serious threat to resources,ecosystems,and biological health.The super-wetting membrane technology can effectively separate oil-water mixtures,but current oil-water separation methods suffer from secondary pollution,difficulty in continuous operation,and low separation efficiency.Therefore,the development of novel oil-water separation materials is of great significance.The essence of oil-water separation is a scientific problem of the penetration or retention of oil or water at the three-phase interface.Nature is the source of inspiration for various technological ideas,engineering principles,and major inventions,providing innovative ideas for the construction of super-wetting separation membranes.The wetting properties of solid surfaces are mainly determined by the microstructure and chemical composition of the surface.By regulating the microstructure and chemical composition of the substrate,it is possible to achieve controllable construction of super-wetting oil-water separation membranes.Covalent organic porous materials have a multi-scale micro-nano pore structure and chemical properties,demonstrating great research and application potential in areas such as adsorption,separation,catalysis,and energy.This article conducts research on the controllable construction of covalent organic porous materials with special wetting properties based on the Schiff base reaction and their oil-water separation performance.The specific contents are as follows:(1)Controllable construction of superhydrophobic multi-scale structured imine polymers and their oil absorption performance research.Based on the Schiff base reaction,a series of controllable micro/nano-structured imine polymers were prepared by using octane-1,8-diamine and benzene-1,3,5-tricarbaldehyde as reaction monomers and regulating the concentration of reaction monomers at room temperature.Modern analytical techniques were used to characterize the microstructure and chemical composition of the prepared imine polymers.The experimental results show that the prepared imine polymers have a spherical structure and a hierarchical porous structure,exhibiting excellent superhydrophobicity with the contact angle greater than 150° at the monomer concentration of 0.15 mol/L.Additionally,the obtained imine polymer nanomaterials with high thermal stability,low adhesion,self-cleaning properties,and alkali corrosion resistance.Furthermore,the superhydrophobic imine polymer nanomaterials also exhibit excellent oil-water separation performance,with a maximum oil absorption capacity of 13 times their own weight.This study provides a new approach for the controllable construction of covalent organic porous nanomaterials with multi-scale structures,which is helpful for the preparation of super-wetting oilwater separation membranes and their application in oily wastewater treatment.(2)Preparation of "filter type" superhydrophobic imine polymer oil-water separation membranes and their oil-water separation research.Using two-dimensional porous metal meshes(brass mesh and copper mesh)as supporting substrates,meshes were treated with APTES bonding or wet chemical etching.Subsequently,loading superhydrophobic imine polymers onto the surface of metal meshes with multi-scale structures to prepare oil-water separation membrane materials with special superhydrophobic/superoleophilic wettability.Utilizing modern instrument analysis techniques to systematically characterize and test these special wettable membrane materials,and conduct comprehensive oil-water separation performance experiments.The experimental results show that these superhydrophobic imine polymer oil-water separation membranes can effectually achieve separation of various oil-water mixtures,with an oil-water separation efficiency of up to99.7 %.Furthermore,the membranes exhibit remarkable characteristics such as high flux,high penetration pressure,high solvent stability,and good cycling performance.Even after 30 cycles,the oil-water separation efficiency remains above 99 %.This study introduces a novel approach to utilizing covalent organic porous materials in oily wastewater treatment,reveals the mechanism of selective separation of target oil components by the three-phase interface,and further enriches the scientific basis theory of superwetting interface.