The Preparation Of Amphiphilic Additives And Their Effects On The Anti-fouling Performance Of Polyacrylonitrile-based Copolymer Composite Membranes

Polyacrylonitrile?PAN?based copolymer is widely used as commercial porous membrane material,because of its good thermal stability,chemical corrosion resistance and mechanical properties.Commercial PAN based copolymer ultrafiltration membranes have been widely used in water treatment,protein purification and food industrial field Unfortunately,PAN based copolymer ultrafiltration membrane is susceptible to contamination due to its hydrophobic property,which may shorten the membrane's life and increase the cost of industrial production.Therefore,amphiphilic copolymers amphiphilic cellulose?MCC-C16?and functionalized graphene oxide?f-GO?were prepared to improve the hydrophilic and anti-fouling performance of the PAN based membrane by simple blending method.The MCC-C16/P?AN-MA?composite membrane was faricated by immersion precipitation phase inversion?NIPS?.The influence of different additive content on the membrane structure,permeability,retention rate,porosity,mechanical properties and anti-fouling properties were investigated in detail.The results manifested that the permeability of P?AN-MA?composite membrane was obviously improved as the MCC-C16 was introduced.When the content of MCC-C16 reached 5 wt.%,compared with P?AN-MA?membrane,the pure water flux increased by 1.6 times,the rejection rate increased by 34%,and the flux recovery rate increased by 44,46%,The pure water flux increased to a maximum of 459 L/m2 h,retention rate of BSA molecules rise up to 95.2%,the flux recovery rate can reach 86.71%.Besides,the fouling rate and resistance of the membrane are also decreased significantly in filtration process.In another part,Silane coupling agent KH570 with long side-chain structure was grafted into GO to widen the lamellar spacing and make it more dispersible in organic solution.Then,the f-GO/P?AN-MA?composite membrane was also faricated by NIPS method.Furthermore,the influence of different additive content of f-GO on the membrane structure,permeability,retention rate,porosity,mechanical properties and anti-fouling properties were also analyzed.The results showed that when the content of f-GO reached 0.5 wt.%,the pure water flux increased to a maximum value of 326 L/m2 h.The BSA flux reached a maximum value of 245 L/m2 h,the pollution recovery rate was up to 98.16%,and the molecular retention rate of BSA protein was as high as 99.33%.Compared with the original membrane,the total fouling was reduced by 30%,and the resistance of the filter membrane decreased from 4.65 10^-12m^-1 to 1.53 10^-12m^-1.In addition,it was found that the composite membrane also had a good anti-fouling property to humic acid and alginate in water system.With the increase of f-GO content,the main pollution of f-GO/P?AN-MA?composite membrane changed from irreversible fouling to reversible fouling.