Improvement of Ag(I) adsorption onto chitosan/triethanolamine composite sorbent by an ion-imprinted technology

摘要

The chitosan/triethanolamine (CTS/TEA) composites including Ag-imprinted CTS/TEA hydrogel bead (Ag-ICTHB) and Ag-imprinted CTS/TEA gel bead (Ag-ICTGB) were prepared by using ion-imprinted technology, in which TEA solution was used as coagulation bath to obtain the two sorbents. The optimization conditions for preparing the sorbents were listed: molar ratio (CTS:Ag(I)) =1:0.10, c(CTS) = 1.0 for Ag-ICTHB and 2.0% for Ag-ICTGB, c(TEA) = 14%, and c(Na_2S_2O_3) = 8.0 g L~(-1) as the elueant. The spectrum of FT-IR implies that bonding are formed between TEA and the primary hydroxyl of CTS, and -NH and -OH of CTS have some interactions with Ag(I). The DSC curve shows that two form of acting force for the adsorption of Ag(I) were appeared in the adsorption between the sorbents and Ag(I). The maximum adsorption capacities of Ag-ICTHB and Ag-ICTGB for Ag~+ are 510 and 350 mg g~(-1), respectively. Moreover, the two beads exhibit good selectivity and durability for Ag~+.