Water-Floating Hydrogel Polymer Microsphere Composites for Application in Hydrological Mining of Cu(II) Ions

Abstract

Innovative materials and technologies capable of extraction and recovery of technologically relevant metal ions from various water sources, such as lakes, oceans, ponds, or wastewater reservoirs, are in great demand. Polymer beads are among the most well-known solid-phase adsorbents and ion exchangers employed in metal ion recovery. On the other hand, hydrogels are an emerging platform for producing innovative adsorbents, which are environmentally friendly and biocompatible materials. In this work, we take advantage of both technologies and produce a new type of material by loading nanostructured polymer microsphere adsorbent into a PVA matrix to obtain a hydrogel polymer microsphere (HPM) composite in the form of a block. The main role of the poly(4-vinylpyrridine-co-methacrylic acid) microspheres is to adsorb metal ions, such as Cu(II), from model water samples. The secondary role of these microspheres in the hydrogel is to change the hydrogel morphology by softening it and stabilizing it under a foam-like morphology. The foam-like morphology endows these composites with the capability of floating on water surfaces. In this work, we report, for the first time, an HPM composite capable of floating on water surfaces and extracting Cu(II) ions from model water samples. This could enable more environmentally friendly hydrological mining technologies by simply deploying adsorbents on water surfaces for metal ion extraction and recovery, thus eliminating the need for water pumping and mechanical processing steps.

Morphological Design and Synthesis of Nanoparticles

“…The research highlights the potential of these nanostructured materials to float on water surfaces, efficiently adsorb and recover ions, and withstand multiple extraction cycles, offering a novel and sustainable alternative to traditional ion-exchange technologies. Further, the work of Honciuc et al [ 10 ] proposes the concept of the hydrological mining of Cu(II) ions, with the help of specially designed nanoparticles–hydrogel polymer–microsphere composites capable of floating on water surfaces. The composite material combines nanostructured polymer microspheres with a polyvinyl alcohol (PVA) matrix, demonstrating the ability to adsorb and recover metal ions efficiently.…”