| With outstanding anti-oxidation, superior thermal and chemical stabilities, and good mechanical properties and tenacity, Polyvinylidene fluoride (PVDF), one of the most popular membrane materials, however, has a major drawback/barrier for applications in water treatment because of its hydrophobic nature, which often results in severe membrane fouling and decline of permeability, while organic-inorganic blending membranes have been proved to be effective to solve this problem.To improve the nano-particles dispersions in casting solution, and enhance the interactions between nano-particles and polymers, TiO2was first immobilized with an initiator, and then grafted via ATRP method with PMMA or PMMA-co-PSBMA, which had good compatibility with PVDF. The grafted TiO2was added into the PVDF casting solution via phase inversion method to prepare the blending membrane of TiO2-PMMA/PVDF or TiO2-(PMMA-co-PSBMA)/PVDF, which possessed high flux and fine anti-fouling properties. The surface hydrophilicity, pore size and antifouling properties of the composite membranes were studied and compared as the grafting conditions varied, such as grafting time, mass ratio of KH-550to TiO2, the dosage of TiO2-PMMA, the dosage of PVP and molar ratio of MMA to SBMA. Tested in filtrating yeast suspension solution, the results suggested that the TiO2-PMMA particles dispersed well and stable in the membrane martrix, and the TiO2-PMMA/PVDF membrane had higher flux and better anti-fouling properties compared with the TiO2/PVDF membrane. The optimal conditions for preparing TiO2-PMMA/PVDF membrane were5h grafting time,3:1mass ratio of KH-550to TiO2, TiO2-PMMA2wt%and PVP5wt%. For the TiO2-(PMMA-co-PSBMA)/PVDF composite membranes, their antifouling properties were further enhanced, which was better than the TiO2-PMMA/PVDF composite membrane under the same conditions. And2:1molar ratio of MMA to SBMA was optimal in forming best antifouling membrane. |
PDF Full Text Request