Advancements in Cr(VI) Removal from Aqueous Solution Using PLA/PBAT/GO/Cloisite 30b Hybrid Nanocomposite Polymer Inclusion Membranes.

Removing heavy metal ions from wastewater reduces health and ecological risks and allows for their reuse. Polymer inclusion membranes with integrated ion carriers offer an efficient solution for removing toxic metal ions from industrial wastewater. These membranes can be further enhanced by using biodegradables polymer blends and incorporating nanofillers to improve their selectivity, stability, extraction efficiency, and biodegradability. In this study, a novel biodegradable polymer blend consisting of 54% poly(lactic acid) (PLA) and 13% polybutylene adipate terephthalate (PBAT) was utilized as the base polymer, with 30% Aliquat 336 as an ion carrier and either 3% graphene oxide (GO) or 3% cloisite 30B (C30B) as nanofillers. The hybrid blend contained a total of 3% nanofillers, with 1.5% graphene oxide (GO) and 1.5% cloisite 30B (C30B). These components were integrated through the evaporation casting method and evaluated for their potential as polymer inclusion membranes (PIMs) for Cr(VI) extraction. Various analytical methods, including X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), were employed to explore the microstructure-property relationships of the fabricated nanocomposite PIMs. The analyses revealed the development of new semi-crystalline membrane structures, resulting in enhanced hexavalent chromium extraction. It was found that the presence of nanofillers altered the bulk structure, creating apparent microvoids in the membranes filled with 3% GO and the hybrid membrane, which were not observed in membranes filled with C30B. This resulted in higher extraction efficiency in the membranes loaded with GO, whereas membranes loaded with C30B exhibited decreased Cr(VI) extraction. An intermediate extraction percentage was found in the hybrid membrane filled with both nanofillers. Additionally, the incorporation of GO and C30B significantly improved membrane stability across various media, reducing mass loss in NaCl/NaOH to 13.36%. The TGA analyses further confirmed that membranes incorporating GO and C30B exhibited improved thermal stability. [ABSTRACT FROM AUTHOR]