Harnessing graft copolymerization and inverse vulcanization to engineer sulfur-enriched copolymers for the selective uptake of heavy metals

This study presents the synthesis of a novel sulfur-based copolymer, S-Tha-Cy, through a unique approach involving graft copolymerization and inverse vulcanization, leveraging cyclooctadiene (Cy) as a crosslinking agent and thioacetamide (Tha) as a grafting monomer. The integration of Tha into the copolymer structure enhances sulfur coordination, exposing additional reactive sulfur sites and incorporating nitrogen-containing moieties. These modifications significantly boost the material’s electron-donating ability, promoting the formation of stable coordination covalent bonds with Hg 2+ ions. S-Tha-Cy demonstrates exceptional Hg 2+ removal efficiency, achieving nearly complete (99.99 %) removal within 30 s, even in competitive environments with other heavy metals. Density functional theory (DFT) calculations confirm a high adsorption energy of −0.508 eV for Hg 2+ , indicating a strong affinity of S-Tha-Cy for mercury. Furthermore, the hybrid material S-Tha-Cy-3-N-Al, which combines S-Tha-Cy with nano-Al 2 O 3 , exhibits sustained Hg 2+ removal capabilities from wastewater. This research presents a breakthrough in the design of sulfur-based materials, offering both innovative synthetic strategies and theoretical frameworks for the efficient capture of heavy metals.