Preparation and embedding–releasing behavior of polyelectrolyte microcapsule

Chitosan microspheres, used as template to prepare polyelectrolyte microcapsule, were prepared by high voltage electrostatic method. Polyelectrolyte membrane made of chitosan and sodium alginate was constructed layer–by–layer assembly. A little residual chitosan template can induce sediment of molecule with negative charge. Acetic acid aqueous solution was used to dissolve the chitosan template. The concentration of sodium fluorescein in the microcapsules linearly increased with time, and embeded concentration became saturated after 15 min. When concentration of sodium fluorescein solution is 2 mg/L, the saturated embeded  oncentration of sodium fluorescein arrived at 10.2 mg/L. The release behavior is mainly affected by microcapsules wall and the structure of template, but concentration of NaCl has little influence on the release behaviour.