Using the Surface Evolver to model droplet formation processes in membrane emulsification

The impact of mass transfer and interfacial expansion rate on droplet size in membrane emulsification processes

“…The relative magnitude of these forces change as the droplet increases in size and has been plotted in the literature [1,12,15]. It has been shown that for micron scale droplets the inertia and buoyancy forces are approximately 9 and 6 orders of magnitude smaller, respectively than the drag and interfacial tension forces and therefore, can be neglected in the force balance model.…”

“…Rayner et al [12] used this free energy approach to model droplet formation from micro-fabricated membranes under quiescent conditions. The input to this model was contact angle, interfacial tension, and pore geometry.…”

“…(28) [12]. If this definition of Laplace pressure seems unfamiliar recall the following geometric relationships for a sphere:…”

“…There are two main detachment mechanisms described in the literature: spontaneous transformation-based (STB) droplet formation and, shear induced droplet formation. Spontaneous transformation-based droplet formation describes situations where the droplets are formed without the necessity of a cross flow and droplet break off occurs due to the minimization of free energy [11,12]. Shear induced droplet formation describes conditions where the flow of the continuous phase affects the size and distribution of the droplets [6,8,13,14] and is generally modelled using a force balance approach.…”

CFD analysis of microchannel emulsification: Droplet generation process and size effect of asymmetric straight flow-through microchannels

“…Van Dijke et al (2008) and van der Zwan et al (2009) modeled droplet generation from a grooved MC using a finite volume method (Star-CD) and a lattice Boltzmann method, respectively. Rayner et al (2004) also used an interactive program (Surface Evolver) to simulate the droplet size for straight flow-through MC emulsification. This program computes the interfacial shape with the minimum free energy in the state of equilibrium.…”