Preparation And Application Of Anti-protein Fouling Ultrafiltration Membrane

Ultrafiltration technology is a new type of membrane separation technology.It uses pressure difference as the driving force and ultrafiltration membrane as the filtration medium to make small molecules and water pass through the membrane and retain large molecules,so as to achieve the purpose of separation,purification and concentration.Ultrafiltration technology is characterized by high efficiency,energy saving,environmental protection,simple operation and easy control.In this study,polysulfone(PS),cellulose acetate(CA)and polyethersulfone(PES)were used as organic polymer membrane materials to prepare ultrafiltration membranes with good anti-protein contamination performance.The PS ultrafiltration membrane was modified by physical blending method,and nano-SiO2,natural soybean lecithin and CA were added as modifiers to increase the hydrophilicity and anti-protein contamination performance of the membrane.Data analysis of pure water flux,protein flux,total pollution resistance,recovery rate and rejection rate,and the morphology of PS ultrafiltration membrane before and after modification by static contact angle(OCA)and scanning electron microscopy(SEM)Characterization and analysis of structure and hydrophilic properties.The results showed that the pure water recovery rate of the modified nano-SiO2 to the bovine serum(BSA)protein solution was 76.88%in the modified ultrafiltration membrane,which was 1.93 times that before the modification.Adding modifier nano-SiO2.natural soybean lecithin blending has a pure water recovery rate of 98.80%for soy protein solution,which is 2.11 times that before modification,and the hydrophilicity of the added modifier is higher than that of the membrane without added modifier.It has also been improved,and the anti-protein contamination effect has been significantly improved.The CA ultrafiltration membrane was prepared by chemical crosslinking modification with glutaraldehyde.The pure water flux,pure water recovery rate,protein retention rate,acid resistance,heat resistance and mechanical strength of the modified CA membrane were mainly studied.SEM,OCA.thermogravimetric analysis(TGA)and FTIR were used to characterize and analyze the morphology,hydrophilicity,stability and structural composition of CA ultrafiltration membranes before and after modification.The results showed that the pure water flux of the membrane reached 2.31×103 g/(m2·min)with a 5wt%glutaraldehyde solution for 40 min and 0.20MP.and the recovery rate of the BSA solution was 97.00%.The recovery rate was 90.60%.In the performance test,the acid resistance,heat resistance and mechanical strength of the membrane were significantly improved,and the modified CA membrane had good anti-protein contamination performance.The citric acid-PVA/PES composite ultrafiltration membrane was prepared by surface coating method.First,the citric acid-PVA crosslinking solution was prepared by chemical method,and then the citric acid-PVA was coated on the PES ultrafiltration membrane by heat treatment.Data analysis of pure water flux,protein flux,total pollution resistance,pure water recovery rate and protein retention rate,and the morphology,hydrophilicity and structural composition of PES membrane before and after modification by FTIR,SEM and OCA Characterize and analyze.The results showed that The recovery rate of PES ultrafiltration membrane after 15min heat treatment in crosslinked solution was 90.90%,1.20 times of that before modification,and 61.20%,1.47 times of that before modification.The hydrophilic properties of the membrane are improved,and the anti-protein contamination effect is significantly improved.