Improved hydrodynamic permeability and antifouling properties of poly(vinylidene fluoride) membranes using polydopamine nanoparticles as additives

This study aims to improve the hydrodynamic permeability and antifouling properties of poly(vinylidene fluoride) (PVDF) membranes using bioinspired polydopamine nanoparticles (PDA NPs) as additives during membranes formation. Based on the oxidant-induced polymerization behavior of dopamine, a series of PDA NPs were first prepared in different reaction mediums. Subsequently, the synthesized PDA NPs were used as additives to produce PVDF/PDA blend membranes. Data of water contact angle measurements show that the hydrophilicity of the blend membranes is improved obviously compared with that of the unmodified PVDF membrane. The water permeability and antifouling properties of the PVDF membranes are both enhanced after blending modification as evaluated by protein filtration tests. Results from tensile test indicate that an appropriate amount of PDA NPs is able to improve the toughness of the as-prepared blend membranes. Moreover, the PVDF/PDA blend membranes have satisfying long-term stability in aqueous environment. This strategy can be extended to more polymers and catechol compounds, and allows exploitation of novel functional composites from bioinspired catecholic chemistry and simple blending process.