Preparation of core-shell ion imprinted nanoparticles via photoinitiated polymerization at ambient temperature for dynamic removal of cobalt in aqueous solution

In this work, novel core-shell ion imprinted polymers were firstly synthesized by photoinitiated polymerization (P-IIPs) for the selective separation of Co(II) in aqueous solution. In contrast to thermal polymerization, photoinitiated polymerization exhibits faster initiation rate, only a quarter of the former, and can be performed at room temperature. Subsequently, extensive characterizations were performed using FT-IR, SEM, TEM, XRD, and TGA. Adsorption isotherm and kinetics studies were carried out in batch adsorption experiments. Furthermore, the removal of Co(II) from aqueous solution was investigated at different conditions by using P-IIPs as the adsorbent in the fixed-bed column and the parameters were discussed and optimized. The data can be well fitted by the Thomas model, offering some model parameters for process design. Compared with non-imprinted polymers, P-IIPs displayed remarkable selectivity toward Co(II). Moreover, the synthesized polymers possessed excellent desorption performance and regeneration property with a desorption efficiency up to 94.1%. P-IIPs enabled the selective extraction of Co(II) successfully from sediment samples with satisfactory recovery. The above mentioned results indicate that P-IIPs are promising high-performance, low-energy and environmentally friendly adsorbents for effectively removing Co(II) from aqueous solution.