Synthesis and properties of diethylene triamine derivative of chitosan

A novel diethylene triamine derivative of chitosan (CTSN) was synthesized via the reaction of diethylene triamine and epoxy activated chitosan. The product contains amino functional groups, secondary amine and polar hydroxyl groups in its skeleton. Its structure was characterized by elemental analysis, infrared spectra analysis, and X-ray diffraction analysis. The results are in agreement with the expectations. The static adsorption properties for Pd2+, Ag+, Ni2+, Cu2+, Co2+, and Cd2+ were studied. Experimental results demonstrated that CTSN had higher adsorption capability for metal ions. Specifically, the adsorption capacities for Ag+ and Pd2+ were 1.29 and 1.15 mmol/g, respectively. With the coexistence of Cu2+ and Ni2+, higher adsorption selectivity of CTSN for Ag+ ion was found. The selectivity coefficients were K A g + / C u 2 + = 11.73 for CTSN and K A g + / C u 2 + = 3.2 for crosslinked chitosan (CCTS). The adsorption capacity for Ag+ was greatly influenced by pH.