Characteristics and Performance of PTU-Cu Composite Membrane Fabricated through Simultaneous Complexation and Non-Solvent Induced Phase Separation

Polymers (Basel). 2021 May 26;13(11):1743. doi: 10.3390/polym13111743.

Abstract

This study aims to integrate copper (Cu) during membrane formation by a facile simultaneous phase separation process to alleviate biofouling and improve membrane performance. Polythiourea (PTU) polymer synthesized through condensation polymerization of 4,4-oxydianiline and p-phenylene diisothiocyanate in dimethyl sulfoxide was used in the preparation of dope solution. By incorporating different concentrations of cupric acetate in the non-solvent bath, both non-solvent induced phase separation and complexation induced phase separation occur instantaneously. Scanning electron microscopy-energy dispersive X-ray, fourier-transform infrared spectroscopy and time-of-flight secondary ion mass spectroscopy analysis accompanied by color change of the membrane surfaces-confirms the interaction of the polymer with Cu. Interaction of Cu at the interface during membrane formation results in a decrease in contact angle from 2 to 10° and a decrease in surface roughness from 30% to 52% as measured by atomic force microscope analysis. Pure water flux of PTU-Cu membrane increased by a factor of 3 to 17 relative to pristine PTU membrane. Both the pristine PTU and PTU-Cu membrane showed antibacterial characteristics against E. coli.

Keywords: composite membrane; macro-molecule metal complex; phase separation; polythiourea.