PVA/Gluten Hybrid Nanofibers for Removal of Nanoparticles from Water

Recent developments in nanotechnology led to the incorporation of many nanomaterials into consumer products. Disposal of such products will lead to potential contamination of the environment. Nanomaterials are emerging contaminants in water and show significant toxicity to living systems. Considering the diversity in structure and properties, removal of nanopollutants from water warrants novel methods and materials. The objective of this study was to prepare PVA/gluten hybrid nanofibers, which are nontoxic and biodegradable adsorbents for the extraction of nanopollutants from water. Surface morphology, elemental composition, and functional groups on the fiber surface were established using microscopic and spectroscopic techniques. Influence of analytical factors such as experimental pH, time, and concentration of the pollutants toward establishing the efficiency of extraction were quantified using UV vis spectroscopy. Nanofiber mats with 5 wt % gluten exhibited high extraction efficiency of 99% toward citrate-capped silver (Ag) and gold (Au) nanoparticles with a maximum adsorptive capacity of 31.84 mg/g for Ag NPs and 36.54 mg/g for AuNPs. The kinetic and equilibrium adsorption data were interpreted using Freundlich and Langmuir isotherm models, and a potential adsorption mechanism was suggested. The adsorption kinetics showed a pseudo-second-order model for the extraction of nanoparticles. The prepared PVA/gluten hybrid nanofibers can be utilized as an efficient low-cost adsorbents for removal and recovery of metal nanoparticles from the aqueous environment.