Papers by Keyword: Cross-Linked Chitosan

Abstract: Using formaldehyde as a crosslinking reagena novel cross-linked chitosan resin was synthesized by orthogonal. The resin material with good properties of sphericity and acidresistivity can be prepared under the optimal experimental conditions, which are found to be 1:6 for the ratio of chitosan and formaldehyde, 60°C for the temperature, 1 h for the reaction time, 640r/min for the stirring rate and 9 for the pH, and the cross-linking rate under the optimal conditions is 401.86%. SEM shows the surface morphology changes of raw materials and products; IR of the raw materials and products shows that the reaction occurs mainly on the amino and the hydroxyl of chitosan, and TG shows that the crosslinking reaction of chitosan can change its heat resistance.

Abstract: Glucose oxidase (GOD) and catalase (CAT) were co-immobilized on the cross-linked chitosan microsphere containing L-Lysine (CCL) by the method of absorption-crosslink, with cross-linking agent of glutaraldehyde. The optimized conditions of the co-immobilization are as follows: activity ratio of GOD and CAT is 0.78:1, concentration of glutaraldehyde is 0.17mmol/L, and the immobilizing process last for 3 hours. The enzyme activity of co-immobilized enzyme is 15.3U/mg and activity recovery is 50.1%. The half life is 231 days, 2.4 times of immobilized GOD.

Abstract: Formaldehyde cross-linked chitosan was used to adsorb sulfate ions from aqueous solution in this study. Batch experiments were conducted to investigate the conditions of the adsorption, the isotherms and kinetics of the adsorption. The optimized conditions of adsorption were as follows: the adsorbent dosage was 0.5g, the equilibrium time was 240min, the initial concentration of sulfate ions was 153.3mg/L, the temperature was 50°Cand the value of pH was 2.2. The maximum adsorption capacity came up to 14.7 mg/g with the adsorption efficiency got to 95.7%. The equilibrium data fitted Langmuir isothermal model well. In addition, the adsorption process could be explained by the second-order kinetic model, and the chemisorption was the limit step for adsorption velocity.