Novel negatively charged hybrids. 2. Preparation of silica-based hybrid copolymers and their applications for Cu~(2+) removal

摘要

A series of negatively charged silica-based hybrid copolymers were prepared via free radical polymerization of γ-methacryloxypropyl trimethoxy silane (MAPTMS), 4-vinylbenzylchloride (VBC), and styrene (St) monomers, and the sol-gel process. Their applications for Cu~(2+) removal from aqueous solution were investigated. TGA and DrTGA thermal analyses indicated that these hybrid copolymers can keep thermally stable up to 412°C. Their cation-exchange capacities (CIECs) are within the range of 0.49-1.25 mmol g ~(-1). Adsorption experiments indicated that the adsorption followed Langmuir isotherm model, suggesting that it is Langmuir monolayer adsorption. The electrostatic attraction between the ionic groups and Cu~(2+), the content of ionic groups and the existence of reactive chloromethyl groups might be responsible for such trend. Based on these findings, it can be concluded that the incorporation of VBC in the hybrid copolymers conduces to the advance of Cu~(2+) adsorption capacity; however, the incorporation of St makes little contribution to the raise of Cu~(2+) adsorption capacity, suggesting that the adsorption performances of these silica-based hybrid copolymers can be artificially adjusted and have potentially application in the removal of Cu~(2+) from wastewater.