原子力显微镜对壳聚糖分形结构的研究

利用原子力显微镜（Atomic Force Microscope,AFM)研究了壳聚糖分子在云母表面的分形聚集生长过程，并对壳聚糖分形生长的作用机理及其生长过程进行研究，发现壳聚糖分子在聚集生长过程呈传统的具有分形特征的正态分布和奇异分布。在壳聚糖聚集生长过程中，由于溶液的自然挥发，形成了云母基片中心位置的壳聚糖浓度相对较高，而周围壳聚糖的浓度相对较低的阶梯分布，因此呈现出中部的胶粒大而周围的胶粒较小的现象。AFM图像显示在云母片的中心部位壳聚糖分子聚集生长为“树”形结构而在边缘部位呈“星”形结构，这两种结构都具有典型的自相似性，壳聚糖的分形生长与其计算机模拟树形模式和DLCA模式拟合得很好。

The Fractal Studies of Chitosan by AFM

The fractal growth of acetyl chitosan molecules on the mica surface was researched by AFM and the mechanism of the fractal growth was discussed We found that the chitosan aggregates showed traditional normal distribution and bizarrerie distribution which had fractal characteristics With the volatilizing of the chitosan solution on the mica surface,a stagewise distribution was formed naturally The concentration of chitosan ,on the center of the mica surface was higher than that on the edge of the mica surface Therefore,the aggregates on the center were larger than those on the edge AFM images showed that the chitosan aggregates on the center of the surface growed as tree-like fractal structure while those on the edge growed as star-like structure Both structures were characteristic of self-comparability The fractal growth of chitosan was well accordant with the tree mode by computer simulation and DLCA mode