壳聚糖膜对水杨酸吸附及释放过程的实时介电谱法研究  

Salicylic Acid Adsorption and Release on Chitosan Membrane——Real-time Dielectric Spectroscopy Study

作　　者：李玉红[1] 宋超[1] 赵孔双[1] 

机构地区：[1]北京师范大学化学系,北京100875

出　　处：《化学学报》2004年第16期1495-1502,共8页Acta Chimica Sinica

基　　金：国家自然科学基金 (No.2 0 2 730 1 0 )资助项目

摘　　要：制备了壳聚糖膜 ,并且测量了壳聚糖膜 /水杨酸溶液、含水杨酸的壳聚糖膜 /蒸馏水两个膜 /液体系的介电谱 ,在 10 0～70 0kHz频率范围 ,发现两种体系都存在显著的介电弛豫现象 ,而且该弛豫的特征参数随壳聚糖膜在相应溶液相中浸泡时间的不同而变化 .将该体系介电模型化、并利用在Maxwell Wagner界面极化理论上建立的公式对介电谱进行解析 ,得到了体系中两相———壳聚糖膜相和溶液相的介电常数和电导率随时间的变化曲线 .通过分析电导变化曲线得知 ,壳聚糖膜对溶液中的水杨酸有吸附现象 ,而含有水杨酸的壳聚糖膜在蒸馏水中可以缓慢释放出水杨酸 ;吸附过程包含的机制有氢键的形成、疏水力和扩散 ;而水杨酸的脱附过程则包含吸附过程几种机制的逆反应 .Chitosan membrane was prepared, and dielectric measurement was carried out on two measuring systems one is the chitosan membrane to immersed in salicylic acid aqueous solution and the other is the chitosan membrane with adsorbed salicylic acid immersed in distilled water. Dielectric relaxations were found for both membrane/liquid systems centering round the frequencies 100similar to700 kHz, and the character parameters of the dielectric spectra varied with the time of the membrane immersed in the corresponding liquid phase. The dielectric spectra were analyzed using the formula based on the Maxwell-Wagner interfacial polarization theory, and time dependence of the electric parameters, permittivity and conductivity, of the two constituted phases, was obtained. By analyzing the variation of the conductivity of the two phases, it was found that the chitosan membrane gradually adsorbed the salicylic acid in the solution, and the membrane with adsorbed salicylic acid slowly released the acid in distilled water. The chitosan membrane adsorbed salicylic acid by formation of hydrogen bond, hydrophobic force, and diffusion, and the slow dissociation of salicylic acid from chitosan membrane by reverse effects of adsorption. The results from this study show the validity of the real-time monitoring for the adsorption and release processes of drug molecule on carrier by dielectric analyzing.

关 键 词：壳聚糖膜 水杨酸 吸附过程 释放过程 实时介电谱法 药物载体 相互作用 

分 类 号：O647.3[理学—物理化学]