Characteristics of adsorption isotherm and kinetic study for newly prepared Co²⁺-imprinted polymer linkage with dipicolinic acid

Co²⁺-complex imprinted polymer (Co-IIP) was prepared by ionic imprinting technology for selective removal of Co²⁺ ions from aqueous solution. Co²⁺ which act as a template ion established a coordination linkage with dipicolinic acid before being copolymerized with functional monomer (methacrylic acid) in the presence of cross-linker (ethylene glycol dimethacrylate) and initiator (2,2′-azobisisobutyronitrile). The surface features and functional groups present in imprinted polymer were characterized by scanning electron micrograph and infrared spectra. The non-imprinted polymer (NIP) was produced simultaneously to serve as controlled polymer. From the isotherm study, adsorption of Co²⁺ ions by ion imprinted polymer (IIP) followed Langmuir isotherm model, which indicates the sorption can be described by monolayer adsorption by give the maximum adsorption capacity was 19.57 mg g⁻¹. This value was comparable to the experimental value which was 18.48 mg g⁻¹ and better affinity compared to NIP. The adsorption kinetics fit a pseudo-second-order and adsorption equilibrium time was around 30 minutes. The present work has successfully synthesized Co-IIP particles with good potential in recognition of Co²⁺ ions. (paper)