Nowadays, polymeric membranes have gained huge attention in separation processes. In this research work, first, ultrafiltration poly(vinyl chloride) (PVC) membrane was prepared through wet-casting of PVC/poly(vinyl pyrroidone)/N-Methy-2-Pyrrolidone solution. The prepared membranes were characterized with respect to surface and interior morphologies, overall porosity, water contact angle, pure water flux, bovine serum albumin (BSA) rejection, anti-fouling properties and long-term and reusability performance. Next, cellulose nanocrystal (CNC) with concentrations of 0.5, 1, 3, 5 7 wt.% with respect to PVC weight and Ar-O 2 vacuum plasma treatment for different exposure times of 2, 4 6 min were considered to modify surface and bulk properties of PVC membrane. It was shown that pure water flux of PVC membrane is positively affected by CNC irrespective of its content. This is attributed to enhanced hydrophilicity and more overall porosity of PVC/CNC membrane in comparison to PVC membrane. The former is resulted from uniform distribution of highly hydrophilic CNCs within the PVC/CNC membrane structure. CNC content of 3 wt.% was recorded as the optimum content by which the highest increase by 461.42% in pure water flux of membrane from 19.44 L/(m 2 h) to 109.14 L/(m 2 h) under operating pressure of 2 bar and BSA rejection of 100% were achieved. Regarding plasma treatment, it was shown that the optimum plasma treatment time can be determined by considering the trade-off between membrane surface hydrophilicity and roughness. In this regard, among different investigated plasma treatment times, i.e. 2, 4 6 min, the optimum one was regarded to be 4 min using which pure water flux increase by 106.89% and 99.34% for PVC membrane and PVC/CNC membrane with CNC content of 3 wt.%, respectively, was observed. A remarkable reduction in BSA rejection was measured for membranes treated by plasma for 6 min. According to the results, it was demonstrated that anti-fouling properties and long-term performance of the prepared membranes are highly correlated to the membrane hydrophilicity and surface roughness. In contrast to the membrane hydrophilicity, surface roughness adversely affects anti-fouling properties and long-term performance of PVC membrane. Overall, CNC and Ar-O 2 vacuum plasma treatment for polymeric membrane modification are only beneficial under optimized operating conditions.
