Controlled Production of Emulsions Using a Crossflow Membrane

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

“…The size of droplets when they detach from the membrane or micro-channel depends on the above mentioned process parameters, which have been evaluated by associating them to forces which act on the system [1,5,[15][16][17][18]. The relative magnitude of these forces change as the droplet increases in size and has been plotted in the literature [1,12,15].…”

“…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.…”

“…1. The key feature of the membrane emulsification process, which sets it apart from conventional emulsification technologies, is that the size distribution of the resulting droplets is primarily governed by the choice of membrane and not by the development of turbulent droplet break up [1]. The main advantages of membrane emulsification are the possibility to produce droplets of a defined size with a narrow size distribution, low shear stress, the potential for lower energy consumption, and simplicity of design [2].…”

Dynamic Pattern Formation in a Vesicle-Generating Microfluidic Device

“…Significant advances have been made in the past few years to produce emulsions that are monodisperse, with standard deviations in droplet size less than 5% [7][8][9][10]. Unlike the standard crossflow techniques for generating water-in-oil emulsions, in which the discontinuous phase is forced through narrow pores [8,10] or capillaries [7,11] into an open continuous phase, we accomplish droplet formation at the junction of two microfluidic channels containing water and an oil surfactant mixture, respectively. The water partially obstructs flow at the junction, but is not broken off at the channel interface as in traditional crossflow devices.…”

Uniform polymer beads by membrane emulsification-assisted suspension polymerisation

“…[16][17][18] Increasing the shear stress will stop the growth of the emerging droplets and result in a faster detachment of droplets, leading to smaller droplets with a higher degree of uniformity. 19,20 Uniform emulsions can be created via SCFM using two types of membranes; standard and ringed membrane, with smaller number of pores for the latter one. A ringed membrane appears to have a remarkable advantage over a standard membrane.…”