Adsorption of asphaltenes at the water-oil interface contributes to the stability of petroleum emulsions by forming a networked film that can hinder drop-drop coalescence. The interfacial microstructure can either be liquid-like or solid-like, depending on (i) initial bulk concentration of asphaltenes, (ii) interfacial aging time, and (iii) solvent aromaticity. Two techniques--interfacial shear...

A drop falling onto a fluid-fluid interface may not merge with it at once but may undergo a so-called partial coalescence cascade. Experimental observations of this phenomenon have revealed fascinating features of the process for Newtonian as well as polymeric fluids. In this paper, we describe numerical simulations of partial coalescence based on a phase-field method. Results show that partial...

We study the effect of surfactants on dynamics a drop-interface coalescence using full three-dimensional direct numerical simulations. employ hybrid interface-tracking/level-set method, which takes into account Marangoni stresses that arise from surface-tension gradients, interfacial and bulk diffusion sorption kinetic effects. validate our predictions against experimental data Blanchette Bigio...

Several processes involve two immiscible liquid phases with dispersed drops surrounded by a continuous phase. The drops coalesce for joining their mother phase. This phenomenon occurs in many industrial mixing, separation, as well as in environmental processes. This paper is focused on the problem of the coalescence of a single drop at the planar interface of two immiscible liquids. An original...

The effect of copolymers on the breakup and coalescence of polybutadiene ~PB! drops in polydimethylsiloxane ~PDMS! is studied using a four-roll mill flow cell. Copolymers are produced at the interface by a reaction between functionalized homopolymers. They reduce the interfacial tension and thus enhance breakup; they also inhibit coalescence of drops. Under the conditions of our experiments, th...

In this research, the effect ofmixed salts together with mixed ionic surfactants on dropinterface coalescence time was studied for the system of water (d) / toluene(c) as a model system. Sodium dodecyl sulf...

• A mechanistic model for the prediction of flow pattern transitions in two-phase, oil-water dispersed pipe flows was developed. Mechanistic can predict separation both oil-in-water and water-in-oil dispersions. Dispersion is controlled by either drop settling rate or coalescence rate. one-dimensional that predicts during liquid-liquid horizontal pipes The able to capture evolution along four c...

Coalescence of liquid drops is critical in many phenomena such as emulsion stability, inkjet printing, and coating applications. For sessile drops on a solid surface, the coalescence process is more complicated than the coalescence of drops suspended in a fluid medium as a result of the coupling of the contact line motions to the fluid flow. In this paper, we use video microscopy to track the e...