Modifying thin film composite membrane with zeolitic imidazolate framework-8@polydopamine for enhanced antifouling property.

Biofouling and organic fouling are major obstacles for polymeric membranes during application. In this work, zeolitic imidazolate framework-8@polydopamine (ZIF-8@PDA) nanoparticles were prepared by an aqueous synthesis strategy and incorporated into the polyamide (PA) selective layer to synthesize thin film nanocomposite membrane (TFN) during interfacial polymerization. The permeability and selectivity of the composite membrane were simultaneously improved with the introduction of ZIF-8@PDA. The water permeability of the TFN membrane increased to 3.74 ± 0.19 L/(m2·h·bar), which is 43.8% higher than that of the control membrane. Besides, the rejection of TFN membrane to sodium chloride is 98.68 ± 0.13%, which shows 0.99% increment than the unmodified membrane. Moreover, organic fouling and biofouling of the TFN membrane were also alleviated thanks to the introduction of the hydrophilic ZIF-8@PDA. The short-term filtration results indicate the performance of the TFN membrane is stable during operation.