2D crystallization of latex particles in films with fluid boundaries
Direct Observation of the Dynamics of Latex Particles Confined Inside Thinning Water-Air Films
K. P. Velikov and O. D. Velev
Langmuir, submitted (1997)
We studied the dynamics of micrometer-sized latex particles entrapped between the surfaces of a free foam film. One of the investigated cases resulted in a method for controlled, multi-step formation of 2D latex crystals of excellent quality. The picture below is a "sneak preview" from the material currently submitted for publication in Langmuir. The diameter of the latex particles in the photos is 7 mm.
Formation of Two-dimensional Structures from Colloid Particles on Fluorinated Oil Substrate
G.S. Lazarov, N.D. Denkov, O.D.
Velev, P.A. Kralchevsky and K. Nagayama,
J. Chem. Soc. Faraday Trans., 90, 2077 (1994).
The main idea of this work is to replace the solid substrate by a layer of fluorinated oil (perfluoromethyl decalin, "F-oil"). The aqueous film into which the particles are crystallized is formed on top of the film of fluorinated oil and is stabilized by appropriate fluorinated surfactants. The fluid film boundaries enhance the action of the capillary forces, and no sticking of the particles to the lower surface is possible, which allows the formation of very large and defect-free 2D crystals. The fluorinated oil substrate can afterwards be dried and the arrays are deposited on the underlying solid support.