Preparation Of Superhydrophilic/Underwater Superoleophobic PVDF Membrane And Separation Performance Of Emulsified Oil-water

With the continuous increase of the discharge of industrial wastewater such as oil or organic solvents,it is harmful to ecosystem security and human health and has attracted worldwide attention.Membrane separation for oil-containing wastewater separation has the advantages of environmental friendliness,high separation efficiency,small footprint,economy,and recycling,and is considered to be the most potential oil-water separation method.However,currently the super-wetting membrane and membrane materials are generally expensive,and the preparation process is complicated and difficult to scale.In actual application,the preparation process is often accompanied by complicated preparation processes,high cost,no recycling,and easy to be polluted.To a certain extent,it limits the application of super-wetting films and film materials in life and industry.Therefore,based on the excellent flexibility and stability of commercial membranes,low production costs,simple processes,and reusable modified membranes provide new ideas for solving problems.The main work of this experiment is as follows:（1）Tannic acid/polyvinylpyrrolidone/SiO₂composite coating modified PVDF membrane for oil/water emulsion separation.Firstly,the original PVDF film is pretreated.Preparing an organic-inorganic composite coating colloidal solution based on natural polyphenols,and the colloidal solution is deposited on the treated PVDF membrane by vacuum assisted self-assembly.Wetting test and separation performance test were carried out on the modified membrane.The oil removal rate of the modified membrane to the emulsion was as high as 99.97%,the flux reached 700 L·m^-2·h^-1,and it had good adhesion And very good oil resistance,four rounds of continuous separation show that the membrane has excellent flux recovery capacity in each cycle（2）Polyethyleneimine/polyvinylpyrrolidone/SiO₂composite coating modified PVDF membrane for oil-in-water emulsion separation.First,Firstly,the original PVDF film is pretreated.Preparing a coating colloidal solution,and it is deposited on the treated PVDF membrane by vacuum-assisted self-assembly.The wettability test and separation performance test were carried out on the modified membrane.The oil removal rate of the modified membrane to the emulsion was as high as 99.0%,the flux reached 700 L·m^-2·h^-1,and it had good adhesion And good oil resistance.