电沉积生物大分子及矿物质膜构建生物材料功能表面的技术越来越受到青睐,在电泳沉积壳聚糖(CS)以获得纳米结构表面时,通过寻找到高定向裂解石墨这一具有原子级平整表面的导电材料作为阴极,排除了金属阴极表面的不平整对电沉积CS的影响,初步探讨了CS电沉积的本身特性及微观机理。采用SEM、TEM、AFM和XRD等表征手段对沉积物表面进行了分析。结果表明经过电泳沉积,CS的(110)晶面结晶峰明显提高,CS的微观结构具有3个层次的定向排列:薄层中的纳米级的分子聚集体的平行排列并组成长条状;这些微米级的长条状结构的平行排列且之间存在的"桥接"结构和沉积物较厚时存在于沉积物表面的微米级的花簇状排列。这也是首次寻找到电泳初始阶段的CS分子聚集体的平行排列和沉积时间较长得到的花簇状结构的生长模式和表面特征。
Electrodepositon techniques,which are adopted to build functional surfaces of biomaterials constituted of biological macromolecules and mineral membranes,are receiving a great deal of attention.In this paper,highly oriented pyrolytic graphite with an atomically smooth surface was employed as the cathode substrate in the electrophoretic deposition of chitosan(CS),eliminating the side effect of the traditional metallic cathode to the revealing of the deposition characteristics of CS itself.SEM,TEM,AFM and XRD were applied to characterize and analyze the deposited CS coating surface.The results showed that,owing to the electric field force,the crystalline peak of its(110) plane was promoted and the orientation arrangement of the CS micro-structure existed in three levels,including the parallel arrangement of nano-scaled CS molecular aggregates in thin layers,the parallel arrangement of CS long strips with a bridge-liked structure joined each other in micron-level composed of those aggregates,and the flower-liked CS in micron-level when the deposit was relatively thick.It has been the first time to explore the parallel arrangement of CS molecular aggregates in the initial stage of electrophoretic deposition and to analyze the growth mode and the surface features of the flower-liked structure.