Contra-diffusion synthesis of ZIF-8 layer on polyvinylidene fluoride ultrafiltration membranes for improved water purification

Contra-diffusion synthesis method was used to create a uniform layer of zeolitic imidazolate framework-8 (ZIF-8) on the porous polyvinylidene fluoride (PVDF) ultrafiltration membranes. SEM, FTIR, EDX, AFM and water contact angle analyses were used to characterize the prepared membranes. The modified membrane with 5 h contra-diffusion synthesis time showed maximum pure water flux of 134 L/m ² h nearly twice of that of the bare PVDF membrane (65.8 L/m ² h). The water purification performance of the prepared membranes was evaluated using dye removal efficiency and the ZIF-8 modified membranes exhibited better performance for dye removal due of the negatively charged surface.