Jump to main content
Jump to site search


Temporal evolution of concentration and microstructure of colloidal flms during vertical drying: A lattice Boltzmann simulation study

Abstract

We study the temporal and structural development of colloid films during vertical drying using the lattice Boltzmann (LB) simulation. The dispersed particles moving in Brownian motion have excluded volume and hydrodynamic interactions in the film. The concentrated colloidal film formed by solvent evaporation is modeled as an uniaxial compression of colloids with a planar moving interface. The simulation studies are carried out over a wide range of Péclet number (Pe), the relative ratio between the evaporation rate and the diffusion rate of colloids. The results clearly demonstrate a temporal variation of colloid concentration as the evaporation rate increases. In the case of high Pe, the increase of colloid concentration in the top layer creates structural features that can be distinguished along the height of the film, and eventually can induce a large tensile stress in the layer. However, surprisingly, the colloids are maximally crystallized in the case of moderate Pe. The LB simulation results are further compared with those from previous studies of the Brownian Dynamics (BD) simulation and the continuum model for evaporation film. The LB and BD results match well both at low and high Pe limits. The qualitatively significant differences between LB and BD simulations at a moderate Pe indicate that hydrodynamic interactions (HIs) play an important role in this Pe. The presence of HIs induces a greater reduction of diffusion than under the geometrical restriction alone, and the effect is conspicuous when particles are driven both by diffusion and by advection.

Back to tab navigation

Supplementary files

Publication details

The article was received on 25 Sep 2019, accepted on 26 Nov 2019 and first published on 28 Nov 2019


Article type: Paper
DOI: 10.1039/C9SM01925A
Soft Matter, 2019, Accepted Manuscript

  •   Request permissions

    Temporal evolution of concentration and microstructure of colloidal flms during vertical drying: A lattice Boltzmann simulation study

    B. Chun, T. Yoo and H. W. Jung, Soft Matter, 2019, Accepted Manuscript , DOI: 10.1039/C9SM01925A

Search articles by author

Spotlight

Advertisements