Improvement of dye and protein filtration efficiency using modified PES membrane with 2-mercaptoethanol capped zinc sulfide quantum dots

Abstract

In this work, novel 2-mercaptoethanol capped zinc sulfide (ZnS) quantum dots (QDs) embedded polyethersulfone (PES) nanocomposite membranes were fabricated which revealed wh improved antifouling properties and dye separation performance. A simple water-based precipitation approach was used to obtain 2-mercaptoethanol capped ZnS QDs at ambient temperature. The resulting membranes were fully identified with SEM, AFM, ATR-FTIR analyses, and also underwent porosity and contact angle tests. The developed nanostructure membranes exhibited a remarkable fouling reduction in bovine serum albumin (BSA) protein filtration, as featured by a declined average surface roughness. The flux recovery ratio (FRR) was improved considerably from 52.6% for the neat PES to 87.9% for nanocomposite membrane by inserting 2 wt.% ZnS QDs. The contact angle of membrane decreased, while porosity size was enlarged by increase of the QDs loading. The prepared nanocomposite membranes showed an increased Reactive Red 195 rejection (from 91.3% to 96.1%) and an enhanced water and dye solution flux (from 121 to 163 L m−2 h−1) with respect to the bare PES membrane. Thus, the results proved the potential of the novel QDs/PES membrane for the dye separation applications.