Based On Ionic Liquid The Surface Modification And Functional Studies Of PVC And PVDF Membrane

PVC and PVDF membranes are widely applied in current membrane market.However,these membranes usually have some limitations such as low permeation flux and protein fouling due to the hydrophobic property.According to previous research,improvement of PVC and PVDF porous membrane surface hydrophilicity is considered to be a useful approach to enhance the permeability and antifouling resistance of protein.Hence,in this paper the surface modification and functional studies of PVC and PVDF membranes were based on ionic liquid.And the antifouling resistance of modified PVC and PVDF membranes ware systematically studied.This paper was consisted of three parts.(1)A novel mimCl ionic liquid brush grafted PVC porous membranes(PVC-g-mimCl)were successfully prepared by nucleophilic substitution reaction on the surface of PVC porous membrane.The effect of mimCl ionic brush grafted density was investigated and the influence of this mimCl brush on the morphology and structure?hydrophilicity and antifouling ability of membrane were investigated systematically.The PVC-g-mimCl membrane was used in the removal of Cr3+ on wastewater treatment.The results showed that the contact angle of modified membrane decreased from 82.70 to 71.6O.And the flux recovery ratio of modified PVC-g-mimCl membrane improved from 51.68%to 81.74%.The anti-fouling ability of PVC-g-mimCl membrane was significantly improved.With the GD increased from 0.15g/m2 to 0.26g/m2,the removal ratio of Cr3+ increased from 8.13%to 48.55%.MimCl ionic brush improved the application value of PVC membrane on wastewater treatment.(2)The PVC-mimCl membrane was prepared via bulk modification.Anion responsiveness to BF4-and PF6-and the influence of anion exchange time,solvent,temperature,salt concentration for the anion responsiveness were investigated.And select optimum reaction conditions through the change of the contact Angle,anion exchange time:2h,temperature:30 ?,solvent:0.25g/ml.The morphology and structure.hydrophilicity and antifouling ability were investigated of PVC-mimX(X=Cl?BF4?PF6).The pore diameter changed of PVC-mimX when anion is different.The anti-fouling ability of PVC-mimCl membrane was significantly improved.And the flux recovery ratio of modified PVC-mimCl membrane improved from 51.7%to 62.8%.Anion responsiveness induced fast,adjustable,and reversible contact angle changes between 63° and 83°.(3)A hydrophilic nanocomposite additive(TiO2-IL)was synthesized by the surface modification of titanium dioxide(TiO2)with[CH2COOHmim]Cl via precipitation technique.And the nanocomposite membrane of PVDF/TiO2-IL was fabricated by wet phase inversion.Then the influence of this TiO2-IL nanoparticle on the morphology and structure?hydrophilicity and antifouling ability of membrane were investigated systematically.The results showed that TiO2-IL nanoparticle improved the hydrophilicity and antifouling.The initial contact angle of membranes dropped about 29.05°.The flux recovery ratio of PVDF/TiO2-IL membrane improved from 51.7%to 62.8%.The BSA adsorption value on the surface of membrane was decreased from 186.83?g/cm2 tO 153.97?g/cm2.