Surface modified electrospun poly(vinyl alcohol) membranes for extracting nanoparticles from water

Abstract

Contamination of water from nanomaterials will be an emerging problem in the future due to incorporation of nanomaterials in many commercial products and improper disposal of waste materials. In this report, electrospun polyvinyl alcohol nanofibers (PVA NFs) with diameters ranging between 300 and 500 nm were used for the extraction of nanosized contaminants from the aqueous environment. To obtain the best extraction efficiency, surface hydroxyl groups of PVA NFs were chemically modified with functional groups, such as thiols and amines. Two model nanoparticles (silver and gold) dissolved in water were used for adsorption studies. Depending on the nature of the surface functionalities, the fibers showed unique ability to adsorb nanoparticles. The extraction studies revealed that the amine and thiol modified PVA NFs showed 90% extraction efficiency for both silver and gold nanoparticles. The thiol and amine functionalized PVA NFs showed maximum adsorption capacities (Q_t) towards Au NPs, which were around 79–84 mg g⁻¹. Similarly for Ag NP extraction, amine functionalized PVA NFs showed a value for Q_t at 56 mg g⁻¹. Our results highlight that functionalized nanofibers have high extraction efficiency for dissolved nanoparticles in water and can be used for removal of the nanocontaminants from the aqueous environment.