Polar modified dendritic post-cross-linked polymer for Cu2+ adsorption.

The polar modified dendritic post-cross-linked polymer, namely HCPD was synthesized and used for adsorptive removal of Cu2+ from aqueous solution. The results showed that 5.12 mmol/g of amino and 2.25 mmol/g of carbonyl groups were uploaded on the polymer and these groups were significantly beneficial for Cu2+ removal. The maximum capacity reached 157.8 mg/g at 313 K and increased as the temperature increased. The Langmuir model characterized the equilibrium data well and a chemical interaction was involved with the enthalpy change of 49.50 kJ/mol. The pseudo-second-order kinetic model described the kinetic data well and the intra-particle diffusion model was appropriate for characterizing the kinetic adsorption. HCPD could be easily regenerated and the regenerated polymers were effectively recycled for five times without significant loss of the equilibrium capacity. Moreover, Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) results revealed that the chelating coordination of the amino and carbonyl groups with Cu2+ was the main driving force for the adsorption.