Research And Application Of The Preparation Performance Of Conductive Polysulfone Ultrafiltration Membrane

Membrane fouling is an inevitable aspect in water treatment that severely limits membrane performance.Therefore,simple and effective membrane fouling monitoring methods are highly sought after to assess the level of fouling before damage occurs or membrane replacement is necessary.Here,conductive blended ultrafiltration(UF)membranes prepared by blending conducting polyaniline(PANI)nanofibers and carboxylated multi-walled carbon nanotubes(MWCNT)in a polysulfone(PSF)matrix were applied in an online fouling monitoring system.First,polyaniline nanofibers were prepared by redox method and rapid mixing,and the scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FTIR),and ultraviolet spectrophotometer(UV-vis)were used to characterized the morphology and structure of polyaniline nanofibers.Then,the PANI/PSF composite membranes were prepared by blending and phase inversion method.The effects of polyaniline content on the composite membrane properties were analyzed by SEM,water flux,contact angle and other characterizations.The results showed that the PANI/PSF composite membrane had better performance than pristine PSF membrane in water flux,hydrophilicity and mechanical strength,and the conductivity was improved to a some extent,which is the basis for the next step research.At last,we explored the effect of MWCNT content on membrane performance by controlling the amount of PANI.In this study,the conductivity of the PSF-based UF membrane was increased by incorporating carboxylated multi-walled CNTs(MWCNTs)and PANI into the polymer matrix,in part acting as conductive fillers and to increase the hydrophilicity but also for inducing increased porosity.All prepared membranes were characterized by transmission electron microscopy(TEM),scanning electron microscopy(SEM)and Fourier transfer infrared spectroscopy(FTIR).Zeta potential,tensile strength,elongation at break,conductivity,pure water flux,and BSA rejection were also assessed.The blended membranes exhibited higher conductivity and water flux(196 L ·m-2·h-1)and had higher porosity and larger pores than the pristine PSF membrane.Moreover,the additional novelty of our work is providing a feasible method(LSV)to detect the resistance change of the UF membrane during the fouling process.An in-house crossflow cell connected to an electrochemical workstation was used to measure the change of resistance by linear sweep voltammetry(LSV)to monitor the fouling process.Exploring the relationship and trends between the permeate flux and system resistance enabled online monitoring of the degree of pollution,which provided a theoretical basis for practical applications.