Synthesis and selective adsorption behavior of Pd(II)-imprinted porous polymer particles

Pd-ion-imprinted polymer particles (Pd-IIPs) with dimensions in the range of 100-400μm were prepared for the selective separation of palladium ions. Two functional monomers, 2-aminobenzonitrile and 4-vinyl pyridine, were self-assembled in the presence of the Pd(II) ion template, followed by co-polymerization with divinylbenzene and styrene via bulk-polymerization. A large surface area was provided by pores induced by a porogenic solvent, and the imprinting effect was realized by removing the template ions from the copolymer particles prepared. The chemical and physical structures of ion-imprinted porous particles were characterized by Fourier transform infrared (FTIR) spectroscopy and energy dispersive X-ray spectroscopy (EDX). The adsorption capacity was investigated using atomic adsorption spectroscopy (AAS) in batch operation mode. The maximum adsorption capacity for the Pd template ion was 38.9mgg^-1, and the selective adsorption effect was clearly illustrated from the increased sorption affinity toward Pd ions over other competitor ions. The adsorption behavior was affected by the pH of the aqueous medium, and enhanced capacity was observed at low pH. The prepared Pd-IIPs could be repeatedly used 10 times after regeneration without a significant loss of adsorption capacity.