Frenkel's method and the dynamic wetting of heterogeneous planar surfaces

McHale, G. and Newton, M.I. ORCID: 0000-0003-4231-1002, 2002. Frenkel's method and the dynamic wetting of heterogeneous planar surfaces. Colloids and Surfaces A - Physicochemical and Engineering Aspects, 206 (13), pp. 193-201. ISSN 0927-7757

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Abstract

The relationship between the edge velocity, vE, and the dynamic contact angle, #, for the spreading of a small spherical cap type droplet on chemically and geometrically heterogeneous surfaces is examined using Frenkel's method. In this method, the change in surface free energy is equated to the viscous dissipation caused by Poiseuille flow inside the spherical cap. To describe dynamic wetting of a surface that is heterogeneous due to small variations in the local surface geometry of the solid, we introduce a simple Wenzel type correction for the ratio of the actual to geometric surface areas, r. The rate of change of surface free energy is then (2izr0)yLy{Q,osd-rr)VE where r0 is the drop base radius, I={y^v- "^L)I%V and the %'s are the interfacial tensions. For partial wetting, I=cos&e where 6e is the equilibrium contact angle and when the viscous dissipation vanishes, Wenzel's relationship linking the equilibrium contact angle on a rough surface to that on a smooth surface is obtained.

Item Type: Journal article
Publication Title: Colloids and Surfaces A - Physicochemical and Engineering Aspects
Creators: McHale, G. and Newton, M.I.
Publisher: Elsevier Science
Place of Publication: Amsterdam
Date: 2002
Volume: 206
Number: 13
ISSN: 0927-7757
Identifiers:
NumberType
10.1016/S0927-7757(02)00076-6DOI
Divisions: Schools > School of Science and Technology
Depositing User: EPrints Services
Date Added: 09 Oct 2015 10:34
Last Modified: 09 Jun 2017 13:33
URI: http://irep.ntu.ac.uk/id/eprint/14930

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