Preparation and characterization of polyvinyl chloride membranes decorated with designed novel zinc oxide particles for mitigating uncontrollable agglomeration

The use of nanomaterials in the fabrication of polymeric composite membranes has a great potential for improving separation performance by altering the membrane characteristics. However, homogeneous dispersion of these fillers in the matrix and stability issues have remained major drawbacks to take a step forward for the commercial applications of such membranes. In this study, polyvinyl chloride ultrafiltration membranes were prepared via direct blending of designed zinc oxide (ZnO) powders (MicNo (R)), that were intentionally agglom-erated in hexagonal platelet forms, into the casting solution by immersion precipitation method. The impact of MicNo (R) loading on the development of membrane microstructure, separation performance and bulk properties were evaluated in comparison to neat PVC and commercial ZnO-doped membranes. Water flux (456 L/m2h) of the 0.05% wt. MicNo (R) platelets containing membranes had 30.6% and 9% higher values with respect to pristine PVC and 0.5% commercial ZnO (c-ZnO) containing membranes, respectively. Although the amount of MicNo (R) platelets (0.05%), added to the membrane casting solution was ten times less than c-ZnO nanoparticles (0.5%), rejection and antifouling properties of the membranes were enhanced significantly due to the large active hy-drophilic surface area of MicNo (R) powders. The highest FRR value after SA removal tests was achieved as 89.9% in the case of PVC/0.05 MicNo (R) membrane with 19% enhancement compared with the pristine membrane. Overall, incorporating MicNo (R) into PVC-based membrane matrix could be a promising approach to cope with the uncontrolled agglomeration and leaching issues with minimal embedment of fillers.

Automated summary

The use of nanomaterials in polymeric composite membranes has the potential to improve separation performance. However, the dispersion and stability of these nanomaterials have been major issues for commercial applications. In this study, zinc oxide powders were blended into polyvinyl chloride ultrafiltration membranes, resulting in improved membrane microstructure, separation performance, and bulk properties. The membranes with 0.05% weight MicNo (R) platelets had higher water flux and enhanced antifouling properties compared to pristine PVC and commercial ZnO-doped membranes.