In this study, a cesium ion imprinted polymer (Cs(I)-IIP) was prepared by free radical thermal polymerization using 18-crown-6-ether (18C6) as ligand, methacrylic acid (MAA) as functional monomer, and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, which can be used for adsorption and separation of cesium ions from low-concentration solutions. The adsorption kinetic and isotherm results showed that the adsorption of Cs + fitted to the pseudo-second-order kinetic model and Langmuir model, indicating that the adsorption of Cs + on Cs(I)-IIP was the monolayer chemical adsorption. The maximum adsorption capacity was 84.21 mg·g − 1 . The selective adsorption properties are performed in Cs + , Li + , Na + , and K + multicomponent systems. The results showed that the Cs(I)-IIP has a high selectivity in the presence of coexisting Li + , Na + , and K + , and the selectivity coefficients ( K’ ) of Cs(I)-IIP for Cs + /Li + , Cs + /Na + , Cs + /K + are 2.1, 1.56, and 1.33, respectively. The high adsorption capacity and selectivity are attributed to the introduction of imprinting technology to form specific Cs + recognition adsorption sites, and the 18C6 cavity was easier to recognize Cs + in the competitive adsorption process. Finally, the Cs(I)-IIP can be regenerated and reused for 10 times with the adsorption capacity only decreased by 8.1%, indicating that the polymer has good reuse performance.
Crown ether is a type of typical macrocyclic polyether compounds, which can produce strong interactions with cationic species, such as metal ions and protonated amines due to its cavity structure and the strong electronegative effect of heteroatoms on the crown ether ring. In this paper, a type of silica based crown ether stationary phase was prepared by covalently bonding dibenzo-18-crown 6-ether (DBCE) on silica gel via copper (I) catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC). The tetraazido DBCE was rapidly prepared by bromomethylation and subsequent azido substitution of DBCE. Finally, this key intermediate was covalently bonded to silica beads by click chemistry to get click-DBCE. Its structure was confirmed by FT-IR and elemental analysis, and the structures of all related intermediates were confirmed by NMR, IR and MS spectra. The crown ether based stationary phase showed good chromatography characteristics and column efficiency (up to 43,553 plates m -1 theoretical plate number is obtained in the case of fluoranthene) under reverse phase liquid chromatographic (RPLC) model. The primary chromatographic evaluation showed that click-DBCE displayed better chromatography efficiency than commercial C18 stationary phase (THERMO BDS HYPERSIL), when they were applied in the separation of regio-isomers of benzene, polycyclic aromatic hydrocarbons (PAHs) and macrolide pharmaceuticals. Furthermore, this stationary phase could also be used to separate fullerenes under normal phase mode, and in this case, 1-chloronaphthalene was suitable additive for improving chromatographic separation ability.