Ball-milled Cu₂S nanoparticles as an efficient additive for modification of the PVDF ultrafiltration membranes: Application to separation of protein and dyes

This study reports the fabrication and application of polyvinylidene fluoride (PVDF) ultrafiltration membranes embedded with various concentrations of the Cu2S nanoparticles. The Cu2S nanoparticles were generated from natural chalcocite applying a high energy planetary ball-milling technique. Non-solvent induced phase separation method was used for the fabrication of the membranes and characterized with scanning electron microscopy (SEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM), porosity and static water contact angle measurements. The results of the contact angle and porosity revealed the increased hydrophilicity and porosity of the nanocomposite membranes as a result of the addition of Cu2S leads to water permeation improvement. The nanocomposite membrane with 0.2 wt% of Cu2S nanoparticles exhibited a maximum water flux of 248.25 Lm-2 h-1 and flux recovery ratio (FRR) value of 92.4%, which showed 65% and 19% increase compared with the control PVDF membrane. Meanwhile, the nanocomposite membranes were able to highly reject the anionic dyes such as reactive blue 21 (RB21), direct black 38 (DB38), and direct yellow 12 (DY12).