Journal of Membrane Science-A facile strategy to enhance PVDF ultrafiltration membrane performance via self-polymerized polydopamine followed by hydrolysis of ammoniumfluotitanate
作者：Lu Shao , Zhen Xing Wang, Yong Ling Zhang, Zai Xing Jiang, Yu Yan Liu
關鍵字：PVDF, Ultrafiltration, Modification, TiO2, Hydrophilicity
論文來源：期刊
具體來源：Journal of Membrane Science
發表時間：2014年
In this study, to overcome the inherent hydrophobicity and improve the comprehensive performance of
polyvinylidenefluoride (PVDF) ultrafiltration (UF) membranes, hydrophilic TiO2particles were utilized
to modify PVDF UF membranes. To obtain the strong binding force and homogenous TiO2distribution on
PVDF UF membranes, polydopamine (pDA) as the“bio-glue”was architecturally built between TiO2and
PVDF membranes, and the modification process was facilely designed via self-polymerization of
dopamine and subsequent hydrolysis of ammoniumfluotitanate. Water contact angle tests proved the
significant improvement in the hydrophilicity of PVDF membranes after modification. The morphologies
of various membranes before and after modification were investigated by scanning electron microscopy
(SEM) and atomic force microscopy (AFM) and the chemical reactions during different modification
stages were evaluated by X-ray photoelectron spectroscopy (XPS) tests. It was found that the pDA layer
via self-polymerization of dopamine on PVDF membranes could assist TiO2 to tightly and homogeneously bind onto PVDF surface for improving the stability and anti-fouling property of membranes
because of the coordination bond (C–OTi) formed between TiO2and pDA, and the pore sizes of PVDF
membranes obviously decreased after modifications. The possible mechanisms during modifications
were discussed. The comprehensive properties of PVDF membranes after such facile modifications had
been greatly enhanced according to the results of waterflux, bovine serum albumin (BSA) rejection, antifouling performance, and TiO2 binding performance characterizations. Both the waterflux and BSA
rejection could be simultaneously improved at the optimized hydrolysis time. Furthermore, the static
and dynamic BSA adsorption tests were carried out. Interestingly, the amounts of BSA adsorption onto
modified membranes demonstrated the opposite trends for the static and dynamic BSA adsorption tests.
The possible reason was clarified based on the competition between the improved hydrophilicity and the
adsorption ability of TiO2. Therefore, TiO2 modified PVDF UF membranes developed by this novel
strategy have attractive potential for water environmental remediation