Analytical Sciences

Abstract − Analytical Sciences, 25(2), 307 (2009).

Deposition and Aggregation of Au at the Liquid/Liquid Interface
Andrew I CAMPBELL,* Robert AW DRYFE,* and Mark D HAW**
*The School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
**Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, Glasgow G1 1XJ, UK
The mesostructure of nanoparticle stabilized interfacial films, in systems such as particle stabilized emulsions, plays a key, yet little understood, role. We have studied a system of gold nanoparticles being formed and aggregating at a planar oil/water interface using optical microscopy. A rapid “nucleation” step of meso (micron) scale aggregates was observed. Aggregation of the meso aggregates to form a percolating structure is seen to switch from a slow to a fast aggregation regime. Aggregation in the slow regime appears to be reaction limited. We tentatively attribute the fast aggregation regime to a capillary attraction.