Enhancing the Cu (II) removal in water using functional hybrid membranes

Abstract

This work developed composite and hybrid membranes of poly(butylene adipate-co-terephthalate) (PBAT) with nanocurcumin (NC) and/or cloisite 20A (C20A). The dispersed phases were characterized by DLS, ζ potential, XRD, SEM, and FTIR, while XRD, SEM, FTIR, mechanical properties, contact angle, and copper sorption evaluated the composite membranes. DLS analysis indicated that the dispersed phases present a nanometric size distribution; ζ potential measurements showed low electrostatic stability, explaining the agglomeration effects observed. Pure PBAT membranes presented macro-pores throughout their structure, which showed a slight size reduction with the inclusion of NC and C20A. The membrane's mechanical performance was affected by the presence of the pores that acted as stress-concentrating defects, and the inclusion of the dispersed phases increased the membrane elastic modulus and tensile strength, especially for PBAT/0.5%C20A with values 18.7 and 8.9% higher than those of pure PBAT, respectively. Composite membranes also showed a hydrophilic nature with all the contact angle measurements lower than 90º. The sorption tests using a high-concentration copper solution (1000 mg/L) showed that the composite membranes achieved a removal of around 25%. These results highlighted the development of new eco-friendly membranes using NC and C20A as dispersed phases with the potential to remove toxic elements from water.