Uniquely modified polyethersulphone and f-CNTs mixed matrix membranes for enhanced water transport and reduced biofouling

• Published in: Desalination and water treatment Vol. 245; pp. 16 - 34
• Main Authors: Nikita, Km, Durga Swetha, C., Murthy, C.N.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-01-2022
• Subjects: Carbon nanotubes; Mixed matrix membranes; Small-angle neutron scattering; Sulfonated polyethersulfone; Carbon nanotubes; Sulfonated polyethersulfone; Small-angle neutron scattering; Mixed matrix membranes
• ISSN: 1944-3986; 1944-3986
• DOI: 10.5004/dwt.2022.27980

Sulfonation of polyethersulfone (SPES) was carried out using chlorosulfonic acid and the modified polymer was then used as a matrix for flat sheet mixed matrix membranes (MMMs). Second component in the MMMs was functionalized multi-walled carbon nanotubes (f-CNTs). The zeta potential study of the cast membranes shows high negative charge on the surface of the membranes containing f-CNTs in comparison to the pristine sulfonated polyethersulfone (SPES) membranes. The addition of carbon nanotubes (CNTs) reduced the roughness parameter of the membranes as revealed by atomic force microscopy study. This also reflected in the reduced irreversible fouling (10.5%). The largest pore size of the membranes having 1.0 wt.% of azide functionalized multi-walled carbon nanotubes was 13.7 nm which classifies them as NF membranes. The highest rejection percentage (91.0%) obtained was for Cu(II) metal by azide functionalized multi-walled carbon nanotubes incorporated membranes. The mechanical stability, in terms of weight loss as observed from thermogravimetric analysis, was the highest as compared to the existing similar membranes with a matching increase in the tensile strength among the membranes of its class.