Europhys. Lett.
Volume 72, Number 4, November 2005
Page(s) 597 - 603
Section Condensed matter: structural, mechanical and thermal properties
Published online 12 October 2005
Europhys. Lett., 72 (4), pp. 597-603 (2005)
DOI: 10.1209/epl/i2005-10271-3

Coalescence of droplets on chemical boundaries

J. Léopoldès and D. G. Bucknall

Department of Materials, Oxford University - Oxford OX1 3PH, UK

received 22 June 2005; accepted in final form 19 September 2005
published online 12 October 2005

We show that emulsion droplets sedimenting toward a chemically patterned substrate can self-assemble and coalesce onto chemical boundaries, leading to a 2D growth pattern. After discussing the various features characteristic of the self-assembly process, we focus on the behaviour of a single droplet when sliding from a high contact angle area to a low contact angle area. The adsorption on the low contact angle area shall occur via two main mechanisms, depending on the interplay between droplet dynamics and wettability contrast.

68.08.Bc - Surfaces and interfaces; thin films and low-dimensional systems (structure and nonelectron properties): Wetting.
61.30.Hn - Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions.

© EDP Sciences 2005