On the Interface Formation Model for Dynamic Triple Lines

This paper revisits the theory of Y. Shikhmurzaev on forming interfaces as a continuum thermodynamical model for dynamic triple lines. We start with the derivation of the balances for mass, momentum, energy and entropy in a three-phase fluid system with full interfacial physics, including a brief review of the relevant transport theorems on interfaces and triple lines. Employing the entropy principle in the form given in [Bothe & Dreyer, Acta Mechanica, doi:10.1007/s00707-014-1275-1] but extended to this more general case, we arrive at the entropy production and perform a linear closure, except for a nonlinear closure for the sorption processes. Specialized to the isothermal case, we obtain a thermodynamically consistent mathematical model for dynamic triple lines and show that the total available energy is a strict Lyapunov function for this system

Voltage-induced spreading and superspreading of liquids

The ability to quickly spread a liquid across a surface and form a film is fundamental for a diverse range of technological processes, including printing, painting and spraying. We show that liquid dielectrophoresis or electrowetting can produce wetting on normally non-wetting surfaces, without needing modification of the surface topography or chemistry. Additionally, super-spreading can be achieved without needing surfactants in the liquid. We use a modified Hoffman-de Gennes law to predict three distinct spreading regimes: (i) exponential approach to an equilibrium shape, (ii) spreading to complete wetting obeying a Tanner’s law-type relationship, and (iii) superspreading towards a complete wetting film. We demonstrate quantitative experimental agreement with these predictions using dielectrophoresis induced spreading of stripes of 1,2 propylene glycol. Our findings show how the rate of spreading of a partial wetting system can be controlled using uniform and non-uniform electric fields and how to induce more rapid super-spreading using voltage control

Voltage-induced spreading and superspreading of liquids

The ability to quickly spread a liquid across a surface and form a film is fundamental for a diverse range of technological processes, including printing, painting and spraying. We show that liquid dielectrophoresis or electrowetting can produce wetting on normally non-wetting surfaces, without needing modification of the surface topography or chemistry. Additionally, super-spreading can be achieved without needing surfactants in the liquid. We use a modified Hoffman-de Gennes law to predict three distinct spreading regimes: (i) exponential approach to an equilibrium shape, (ii) spreading to complete wetting obeying a Tanner’s law-type relationship, and (iii) superspreading towards a complete wetting film. We demonstrate quantitative experimental agreement with these predictions using dielectrophoresis induced spreading of stripes of 1,2 propylene glycol. Our findings show how the rate of spreading of a partial wetting system can be controlled using uniform and non-uniform electric fields and how to induce more rapid super-spreading using voltage control