Preparation And Properties Of High Performance Polyethersulfone Ultrafiltration Membrane

Ultrafiltration?UF?is a mature separation technology,which is widely used in pharmaceutical,dairy,protein and food industries.Among the various membrane materials,PES has received extensive attentions in UF membrane because of its excellent anti-oxidation,thermal and hydrolytic stability.However,PES membrane is easy to be fouled by proteins and other molecules due to its hydrophobicity,resulting in the increased energy consumption and the reduced membrane life.Therefore,how to improve the antifouling performance of PES membrane has become a research focus of membrane technology.In this paper,a modified polyethersulfone ultrafiltration membrane was prepared by non-solvent induced phase separation?NIPS?method.By exploring different additives and different coagulation baths,the influence of the structure and performance of the modified membrane was explored by means of scanning electron microscope,atomic force microscope,static water contact angle test,water flux test,and antifouling test.The specific research content is as follows:1.PB,as a kind of MOFs-like material,was added to the PES material for preparation of PB/PES UF membrane by NIPS method.Due to the large amount of charge on the surface of the PB,the load capacity of the modified PES membrane was enhanced.The results show an improvement of membrane permeability with increasing PB-NPs content up to 0.2wt%was observed.The pure water flux was 107.37 L m^-2h^-1,which was 72.8%higher than PES membrane.The filtration experiment of BSA aqueous solutions with different p H values showed that,when the BSA aqueous solution was p H<3.55 or p H>5.0,the addition of PB-NPs not only increased the charge-loading capacity of PES membrane surface,but also improved the antifouling performance of the PES membrane,the FRR value reached 90.73%.2.A citric acid-modified Prussian blue?CPB?was prepared by a hydrothermal synthesis method,and the surface was provided with a large number of carboxyl groups and hydroxyl groups,thereby improving the hydrophilicity of the membrane.Through the static water contact angle test,the hydrophilicity of the CPB/PES membrane was significantly improved.With the addition of CPB-NPs,the permeability and antifouling performance of the membrane have been improved.The water flux of membrane M9reached 117.39 L m^-2 h^-1,the rejection rate of BSA reached 89.73%,and FRR the value reached 94.81%.3.PES ultrafiltration membranes were prepared to use different coagulation baths,and their structures and properties were studied.By comparing the static water contact angle,water flux test,and antifouling test of CS coagulation baths and PVA coagulation baths of different ratios prepared PES membrane,it was found that in the interval of 0.1wt%to2wt%,the same percentage of the membrane prepared by the CS coagulation bath was more hydrophilic than the PVA coagulation bath,and the antifouling performance of the membrane prepared by the CS coagulation bath with the same ratio was better than that prepared by the PVA coagulation bath.