扫描隧道显微镜研究银胶的表面结构和凝聚行为

SURFACE STRUCTURE AND AGGREGATION BEHAVIOUR OF COLLOID SILVER PARTICLES BY SCANNING TUNNELLING MICROSCOPY

采用扫描隧道显微镜(STM)详细研究了银胶的表面结构和NaCl对其凝聚状态的影响,并与透射电子显微镜(TEM)的结果进行了比较。结果表明银胶颗粒表面原子处于有序与无序状态之间,部分原子以聚集体(如二聚体或多聚体)的形式存在,另一部分原子则处于松散状态。而且,NaCl的存在明显改变了银胶的凝聚状态,主要表现为NaCl诱导的银胶颗粒发生链状和网状凝聚。

The surface structure and aggregation behaviour of colloid silver particles was investigated by Scanning Tunnelling Microscopy and Transmission Electron Micros-copy. The results indicate that the existing state of the surface atoms of colloid Ag particles is between ordered state and disordered state, some atoms form small clusters(such as dimer). Moreover, the aggregation state of Ag sol was obviouslx changed by addition of NaCl. The major aggregation behaviour, namely the chain-like and network aggregation, was induced by NaCl.