Short-time self-diffusion of weakly charged silica spheres at aqueous interfacesWei Chen and Penger Tong
Department of Physics, Hong Kong University of Science and Technology - Clear Water Bay, Kowloon, Hong Kong
received 7 April 2008; accepted in final form 9 September 2008; published October 2008
published online 7 October 2008
Optical microscopy and multi-particle tracking are used to study the short-time self-diffusion of weakly charged silica spheres at a water-air interface. The measured short-time self-diffusion coefficient DSS has the form, DSS/D0= (1- n), where n is the area fraction occupied by the particles and D0 is the Stokes-Einstein diffusion coefficient of individual particles in the bulk fluid. The obtained values of and differ from those obtained for bulk suspensions, indicating that hydrodynamic interactions between the interfacial particles have interesting new features when compared with their three-dimensional counterpart.
82.70.Dd - Colloids.
68.05.Gh - Interfacial properties of microemulsions.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
© EPLA 2008