A Study On The Preparation Of Chitosan Microcapsules

Chitosan is a safe, environment compatible polymer. It does no harm to human being and is easy to be biodegraded. All these characteristics make the chitosan widely used in biochemical and medicinal field. Through orthodox experiment, we analyzed the degraded process of chitosan, found the optimal condition for chitosan degrading is: the concentration of H2O2 is 4%, at the temperature of 50, reaction time is 4hr and HAc concentration is 2.5%. After the chitosan was degraded, the two main parameters were analyzed: D.D and viscosity.In this thesis, we studied the principle and method of preparing Chitosan-glutin microcapsule by complex coacervation, which was composed of n-nonane as core material, chitosan and glutin as shell material. Then we investigated the main factors affecting the form of microcapsule, such as system concentrations, pH value,association time, complex coacervation time, emulsification speed,ratio of shell/core materials. Finally, we set suitable reactionconditions for the reaction.The size and its distribution of microcapsule particles are important parameters of microcapsules. It would affect not only the slow release property of microcapsule, but also the isolation property of microcapsule. After the microcapsules were prepared, the morphology and size of the microcapsule particle were investigated by electron microscope. The results show that the prepared microcapsules have regular and round appearance with average particle size about several micro -meters, and its size distribution is more narrow.In addition, we studied the slow release property of core material in microcapsules, such as temperature, particle size and association degree, etc. The stability of microcapsule dispersingsystem to temperature and pH value was investigated as well. The results showed that the microcapsule prepared is stable to temperature and pH value, and satisfied the requirements in later process, storage and application, which makes it suitable for biochemical, pharmaceutical, foodstuff and cosmetic industry.