ORGANIC SOLVENT ULTRAFILTRATION MEMBRANE OF POLYIMIDE/POLYETHYLENEIMINE@TiO2 WITH HIGH SOLVENT PERMEABILITY AND METHOD OF PRODUCING THE SAME

A method for preparing a solvent resistant polyimide/polyethyleneimine@titanium dioxide nanohybrid ultrafiltration membrane with high solvent permeability, the method comprises the following steps:

• 8 to 13 parts by mass of polyimide and 50 parts by mass of N-methylpyrrolidone (NMP) are mixed and stirred to form a uniform homogeneous solution;
• 1 to 5 parts by mass of a solution of titanium (IV) bis(ammonium lactato)dihydroxide (Ti-BALDH) containing 40 wt % to 60 wt % N-methylpyrrolidone is added to the homogeneous solution, and an uniformly mixed solution is obtained after being stirred, then let it stand for defoaming to obtain a casting solution;
• the casting solution is coated onto a non-woven fabric, then the non-woven fabric is immersed into 1000 parts by mass of a coagulation bath aqueous solution containing polyethyleneimine, as a result of which the non-solvent induced phase separation, the chemical crosslinking of polyethyleneimine and polyimide, and Ti-BALDH in-situ biomimetic mineralization catalyzed by polyethyleneimine are simultaneously carried out for 1 to 8 hours, then the residual cross-linking agent polyethyleneimine on a membrane surface is rinsed with deionized water, and the membrane is placed in ethanol for storage to remove residual solvent, and finally the polyimide/polyethyleneimine@titanium dioxide nanohybrid ultrafiltration membrane is obtained.