U Thiele et al 2009 J. Phys.: Condens. Matter 21 264016 doi:10.1088/0953-8984/21/26/264016
U Thiele1, I Vancea1, A J Archer1, M J Robbins1, L Frastia1, A Stannard2, E Pauliac-Vaujour2, C P Martin2, M O Blunt2 and P J Moriarty2
Show affiliationsWe review recent experiments on dewetting thin films of evaporating colloidal nanoparticle suspensions (nanofluids) and discuss several theoretical approaches to describe the ongoing processes including coupled transport and phase changes. These approaches range from microscopic discrete stochastic theories to mesoscopic continuous deterministic descriptions. In particular, we describe (i) a microscopic kinetic Monte Carlo model, (ii) a dynamical density functional theory and (iii) a hydrodynamic thin film model.
Models (i) and (ii) are employed to discuss the formation of polygonal networks, spinodal and branched structures resulting from the dewetting of an ultrathin 'postcursor film' that remains behind a mesoscopic dewetting front. We highlight, in particular, the presence of a transverse instability in the evaporative dewetting front, which results in highly branched fingering structures. The subtle interplay of decomposition in the film and contact line motion is discussed.
Finally, we discuss a simple thin film model (iii) of the hydrodynamics on the mesoscale. We employ coupled evolution equations for the film thickness profile and mean particle concentration. The model is used to discuss the self-pinning and depinning of a contact line related to the 'coffee-stain' effect.
In the course of the review we discuss the advantages and limitations of the different theories, as well as possible future developments and extensions.
61.20.Gy Theory and models of liquid structure
Soft matter, liquids and polymers
Issue 26 (1 July 2009)
Received 8 January 2009, in final form 23 February 2009
Published 11 June 2009
U Thiele et al 2009 J. Phys.: Condens. Matter 21 264016
C Niemann et al 2003 J. Phys. D: Appl. Phys. 36 2102