Characteristic Times for Pressure and Electrostatic Force Driven Thin Film Drainage

Crawford, David G.; Koch, Charles Robert; Bhattacharjee, Subir

doi:10.1166/jctn.2008.1014

Cited by 1 publication

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some recent experiments have demonstrated that the presence of an external electric field can lead to very rapid drainage of such free films compared to conventional pressure-based drainage − (Figure b). Our early theoretical studies also investigated and supported this phenomenon by comparing the drainage times and final patterns to those obtained during solely pressure-based drainage . During the compression of the liquid film in emulsions by the application of an electric potential, an interesting situation may arise if different additives and surfactants are mixed together in an emulsion.…”

Section: Introductionmentioning

confidence: 82%

“…The scaled spatial dimensions are given by X = x /λ, Y = y /λ, and T = tu 0 /λ, where u 0 is the characteristic velocity. More detailed derivations of these equations can be found elsewhere. , …”

Section: Mathematical Modelingmentioning

confidence: 99%

“…More detailed derivations of these equations can be found elsewhere. 26,67 Disjoining Pressure. As the considered liquid film is very thin (<100 nm), the length scale of intermolecular interactions is comparable to the film thickness.…”

Section: ' Mathematical Modelingmentioning

confidence: 99%

“…By solving the above set of equations analytically for a thin film trapped between two homogeneous electrodes, the derived electrostatic disjoining pressure and the electric field at the filmÀbounding fluid interface are given by, 3,67 respectively,…”

Section: ' Mathematical Modelingmentioning

confidence: 99%

“…Our early theoretical studies also investigated and supported this phenomenon by comparing the drainage times and final patterns to those obtained during solely pressure-based drainage. 67 During the compression of the liquid film in emulsions by the application of an electric potential, an interesting situation may arise if different additives and surfactants are mixed together in an emulsion. It can be observed from Figure 1b that different additives and surfactants will eventually introduce chemical heterogeneity at the interfaces.…”

Section: ' Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Influence of Electrostatic and Chemical Heterogeneity on the Electric-Field-Induced Destabilization of Thin Liquid Films

et al. 2011

Self Cite

View full text Add to dashboard Cite

A numerical model for thin liquid film (<100 nm) drainage in the presence of an external electric field is developed. Long-wave theory is applied to approximate and simplify the governing equations. A spatiotemporal film morphology evolution equation thus obtained is then solved using a combination of finite difference to resolve the spatial dimensions and an adaptive time step ODE solver for the temporal propagation. The effect of fluid properties, namely, viscosity and surface tension, on the film drainage time is observed for a homogeneous electric field, which leads to random dewetting spots. Electrically heterogeneous fields, achieved by modeling electrodes with various periodic patterns, are explored to identify their effect on the drainage time and behavior. Finally, the chemical heterogeneity of the substrate is coupled with the periodic electric heterogeneity to understand the implications of combined heterogeneity. It is observed that the introduction of any heterogeneity results in faster drainage of the film when compared to that of the homogeneous field. In all cases, the thin film is drained, leaving submicrometer-scale structures at the interface. Well-controlled surface patterns are found on the application of periodic heterogeneity. This study effectively demonstrates the immense potential of electrically induced thin film drainage as a means for faster de-emulsification and for the creation of ordered submicrometer-scale surface patterns on soft materials.

show abstract