The Synthesis And Property Of The Chitosan Complexes

Chitosan is one sort of natural alkali polysaccharide with favorable biological activity and medical activity which is extracted from the shell of the Crustacea animals such as shrimp or crab etc. It has favorable coordination capability to many transition metal ions and rare metal ions. As a kind of complex material, the chitosan-metal complexes coordinated from chitosan or carboxymethyl chitosan and metal ions have a lot of outstanding capabilities and therefore will be widely used in many areas such as development and production of nutritious food, development of pharmaceutical carriers, development of immobilization of enzyme and separation or determination of metal ions etc.This thesis studied the synthesis of the chitosan and the carboxymethyl chitosan complexes such as chitosan-selenious acid complex, chitosan-ferric complex, chitosan-falcial complex, carboxymethyl chitosan-ferric complex and carboxymethyl chitosan-falcial complex. The structure and the property of the coordinating compounds were characterized by IR(infra-red) sepectrometry, UV(ultraviolet) sepectrometry and elementary analysis etc. The static adsorptive characteristics and adsorption kinetics between chitosan, selenious acid(H₂SeO₃) and the metal ions (Fe³⁺, Ni²⁺)have also been investigated and the respective isothermal adsorption equations have been deduced. The thesis is divided into several parts:1. A summary about the synthesis, the structure , the property specially the research advances and the applications of chitosan and carboxymethyl chitosan is given.2. The static adsorptive characteristic and adsorption kinetics between chitosan and selenious acid have been investigated. The chitosan-selenious acid complex has also been prepared under the optimum adsorption conditions, and its physicochemical properties were studied. The structure of the chitosan-selenious acid complex was characterized by IR sepectrometry, UV sepectrometry and elementary analysis etc. The preliminary composition of the chitosan-selenious acid complex was determined .The results indicated that the adsorptive capacity of chitosan to selenious acid was influenced dramatically by pH value, adsorptive time, adsorptive temperature, concentration of the selenious acid and the use level of the chitosan. Complex adsorptive reaction was occurred between chitosan and selenious acid. The adsorptive behavior of chitosan met with the Langmuir monomolecular layer adsorptive mechanism and the absorption isotherm equation met with the Langmuir absorption isotherm equation. In the mean time , the absorption isotherm equation met with the Freundlich absorption isotherm equation as well.