Preparation and properties of PVDF membrane modified by polyethylene imine grafting/microsphere blending

Abstract

Polyvinylidene fluoride (PVDF) is a kind of membrane material with excellent performance. However, the hydrophobicity of the membrane surface can easily lead to membrane fouling, which hinders its practical application in wastewater treatment. In order to improve the surface hydrophilicity of PVDF, three kinds of copolymer microspheres with different particle sizes were synthesized, and then polyethyleneimine was grafted on the surface of the membrane. The PVDF membrane modified by polyethyleneimine grafting/microsphere blending was tested by FTIR, XPS, SEM, Zeta potential and other analysis tests. The oil-water separation performance, protein contamination resistance, and dye adsorption and retention performance of the membrane were investigated. The results showed that the modified membrane was hydrophilic and oleophobic underwater, and the separation efficiency of oil-water emulsion was above 99%. The membrane was resistant to protein pollution, and the flux recovery rate of bovine serum albumin after filtration could reach 99.3%. It could adsorb and intercept anionic dyes, and the interception rate of Congo red dye was above 90%.

Keywords

• microspheres
• polyvinylidene fluoride membrane
• hydrophilic modification
• sewage treatment