Quaternary ammonium-functionalized polymer for selective Pt(IV) recovery from waste-derived chloride leachates

Quaternary ammonium-functionalized polymer for selective Pt(IV) recovery. • Rapid Pt(IV) adsorption with equilibrium reached within 30 min. • High experimental Pt(IV) uptake capacity of 701.54 mg/g. • Preferential Pt(IV) capture in waste-derived chloride leachates. • More than 95% adsorption efficiency after five adsorption–desorption cycles. The covalent functionalization of polymeric matrices provides an effective strategy for tailoring their affinity toward specific metal species. In this work, chloromethylated polystyrene was functionalized with N , N -dimethylbutylamine through a one-step grafting reaction to construct a quaternary ammonium-functionalized polymer (CPR-DMBA) for selective Pt(IV) capture. CPR-DMBA exhibited rapid adsorption kinetics (equilibrium within 30 min), a high uptake capacity (701.54 mg/g), and preferential adsorption of Pt(IV) over competing metal ions in both synthetic solutions and waste-derived leachates from electronic waste and spent automotive catalysts. The adsorbent retained more than 95% adsorption efficiency after multiple cycles. Spectroscopic and theoretical analyses suggest that the adsorption process is governed primarily by electrostatic interactions and ion exchange, with additional contributions from weak non-covalent interactions. These results demonstrate that covalent functionalization of polystyrene with quaternary ammonium groups provides an effective route for constructing functional polymeric materials for selective capture of anionic metal complexes. Download: Download high-res image (100KB) Download: Download full-size image