Alginate 겔 표면에서 Chitosan 흡착제어 특성: pH와 농도의 영향

Abstract

Polyelectolytic adsorption characteristics of chitosan on alginate gel was investigated as a function of pH of solution andansolution containing CaCl2. The amount of adsorption on the alginate beads was estimated by measuring the residual chitosan inthe solution through the colorimetric method using cibacron red dye. Duration time to achieve a equilibrium adsorption wasdetermined to 20 min. Increase of the adsorbed amount of chitosan on the bead was observed as the alginate concentrationincreased. which may be due to the higher density of the surface carboxyl group at the higher concentration. Aldo, the adsorptionamount of chitosan was affected by pH of the adsorption medium, and it was about 30% higher at pH6 compared to pH3.Equilibrium adsorption of chitosan on the bead was analyzed using Langmuir isotherm and the adsorption characteristicparameters, Langmuir constant (K) and specific maximum adsorption density ( ), were determined as a function of theK appeared to decrease as the alginate concentration increased and pHdecreased. It may be suggested that lower K may be explained by the steric hindrance caused by the higher density of surfacecharge at the higher alginate concentration and the reduced charge density at lower pH. were estimated to 66g/cm2at pH6and 3% alginate bead. In sumary, the preparation of chitosan membrane on alginate gel bead can be controlled by adjusting thealginate concentration and the preparation pH, which may be applied to controlling the release rate of drugs and the permeationproperties of the capsules of enzymes or cells.