Thiol-Functionalized Hybridized Porous Polymer on Polyurethane Foam for Recyclable Adsorption of Multiple Ions

Abstract

The pollutants in the excessive discharge of industrial and daily wastewater, which contain multiple metal ions and anions, will cause irreversible damage to the environment and human body. However, current adsorbents only possess adsorption ability toward single type of ion, thus greatly limiting the adsorption efficiency. In this work, we prepared thiol functionalized poly(di(4-vinylpyridine)-zinc chloride-co-divinylbenzene) (Poly(ZnVP2-co-DVB)-SH) with a semicoordinated structure, coordinated/covalent hybridized skeletons, and thiol functional groups via a coordination-polymerization method. On the basis of the radical polymerization, we developed an in situ and facile method to graft Poly(ZnVP2-co-DVB)-SH on polyurethane foam (PU). Due to the semicoordinated structure and thiol groups, the composited foam demonstrated the adsorption capacity toward different ions (Pb2+, Cu2+, and PO43–). The saturated adsorption capacity of the composited foam toward Pb2+, Cu2+, and PO43– can reach to at 228.4, 91.3, and 160.1 mg·g–1, respectively. The adsorption capacity of PO43– is appreciably higher than that of the phosphate adsorbents except the biochars. Adsorption mechanism investigation reveals that the adsorption ability toward multiple ions is arising from multiple interaction, including the coordination centers exchange, thiol-lead reaction, anion exchange, and direct reaction between pyridine-phosphate. The foam can be recycled at least three times. Besides, it shows removal percentages for Pb2+, Cu2+, and PO43– in real urban wastewater. Overall, the modified foam demonstrates a high and multifunctional performance, which is potentially used for water treatment.