Preparation And Performance Study Of Bromide Ion-Lanthanum Nitrate Modified Chitosan Imprinted Polymer

Molecular imprinting technology is one of the hot research topics in recent years, the imprinted polymer has specificity adsorption ability to the imprinted molecules and has extensive application value in terms of material separation and enrichment.Based on the molecular imprinting technique, taking lanthanum nitrate modified chitosan as the functional monomer, the bromide ion as the imprinting template, glutaraldehyde as the crosslinker, NaOH solution as eluent solution, bromide ion-lanthanum nitrate modified chitosan imprinted polymer was prepared in this paper by using the surface molecular imprinting method. The optimum preparation conditions and influencing factors for the imprinted polymer were obtained by considering the amount of functional monomer, crosslinker, reaction time and reaction temperature. Adsorption equilibrium time, the maximum adsorption capacity, specific adsorption performance and repetition durability for the imprinted polymer’s adsorption performance were obtained by static adsorption experiments and the imprinted polymer was measured by scan electron microscope and Fourier transform infrared spectroscopy. The imprinted polymer was applied on the adsorption of bromide ions in seawater and the effect of the major competitive anions in seawater were considered for the adsorption performance of the imprinted polymer. Then it was used in artificial seawater and concentration seawater for bromine adsorption and the adsorption type for bromine adsorption was determined.H2O2oxidation-extraction photometric method was used for the determination of bromide ion concentration. The optimal preparation conditions were:the amount of functional monomer was0.5g, the amount of crosslinker was1.0mL, reaction time was10h, reaction temperature was20℃and the concentration of eluent solution NaOH was1mol/L. The amount of functional monomer and crosslinker had a great influence on adsorption performance for the imprinted polymer. The experiments showed that the adsorption equilibrium time was30min and the maximum adsorption capacity was4.81mg/g, it also had good specific adsorption performance and repetition durability. Further research indicated that Cl-and F-in seawater had significant impact on the adsorption performance for the imprinted polymer, but SO42-and HCO3-had less effect. Adsorption performance for artificial seawater and concentration seawater was good and its adsorption type was monolayer adsorption.