Thiol-Functionalized\nHybridized Porous Polymer on\nPolyurethane Foam for Recyclable Adsorption of Multiple Ions

Abstract

The\npollutants in the excessive discharge of industrial and daily\nwastewater, which contain multiple metal ions and anions, will cause\nirreversible damage to the environment and human body. However, current\nadsorbents only possess adsorption ability toward single type of ion,\nthus greatly limiting the adsorption efficiency. In this work, we\nprepared thiol functionalized poly(di(4-vinylpyridine)-zinc chloride-<i>co</i>-divinylbenzene) (Poly(ZnVP₂-<i>co</i>-DVB)-SH) with a semicoordinated structure, coordinated/covalent\nhybridized skeletons, and thiol functional groups via a coordination-polymerization\nmethod. On the basis of the radical polymerization, we developed an\nin situ and facile method to graft Poly(ZnVP₂-<i>co</i>-DVB)-SH on polyurethane foam (PU). Due to the semicoordinated structure\nand thiol groups, the composited foam demonstrated the adsorption\ncapacity toward different ions (Pb²⁺, Cu²⁺,\nand PO₄^3–). The saturated adsorption\ncapacity of the composited foam toward Pb²⁺, Cu²⁺, and PO₄^3– can reach to at 228.4, 91.3,\nand 160.1 mg·g^–1, respectively. The adsorption\ncapacity of PO₄^3– is appreciably higher\nthan that of the phosphate adsorbents except the biochars. Adsorption\nmechanism investigation reveals that the adsorption ability toward\nmultiple ions is arising from multiple interaction, including the\ncoordination centers exchange, thiol-lead reaction, anion exchange,\nand direct reaction between pyridine-phosphate. The foam can be recycled\nat least three times. Besides, it shows removal percentages for Pb²⁺, Cu²⁺, and PO₄^3– in real urban wastewater. Overall, the modified foam demonstrates\na high and multifunctional performance, which is potentially used\nfor water treatment.