Fabrication and Characterization of Poly(Lactic Acid) (PLA)/Ethylene Vinyl Acetate (EVA)/Graphene Oxide (GO) Polymer Composites for the Purpose of Removing Lead Ions (Pb(II)) from Water

The contamination of water by heavy metals is a global problem with distressing health consequences, and researchers have proposed various methods to remove these ions. This study explored poly (lactic acid) (PLA)/ethylene vinyl acetate (EVA)/graphene oxide (GO) composites as possible adsorbents of lead ions from water. GO was synthesized using modified Hummer’s method, and melt mixing was used to prepare the polymer blends and composites. Morphology investigations showed that PLA and EVA were immiscible, GO preferred to settle on the interface between the two polymers, and GO had a partial miscibility and compatibility effect on the polymers, even though cracks and voids were observed with increasing GO content. In water absorption studies, the early hydrolytic degradation of PLA was avoided by incorporating EVA, resulting in reasonable water absorption rates. The 50/50 w/w PLA/EVA blend and its composites showed a high-water intake. In Pb(II) adsorption studies using AAS, all the analyzed samples had very high Pb(II) adsorption capacities, and the 66.5/28.5/5 w/w PLA/EVA/GO composite adsorbed the most lead ions, under basic media, and a 5 h contact time. Adsorption kinetic modeling suggested that a homogenous adsorption process took place, with a precise Langmuir isotherm. The developed materials are promising commercial lead ion adsorbents that are environmentally friendly.