Numerical Study of Surfactant Dynamics during Emulsification in a T-Junction Microchannel

• DOI: 10.1021/acs.langmuir.8b00123
• Publication Date: 2018-03-30T05:17:24Z
• Authors: Antoine Riaud; Hao Zhang; Xueying Wang; Kai Wang; Guangsheng Luo
• Keywords: Microchannel; Lattice Boltzmann methods; Coalescence (physics); Velocimetry

Microchannel emulsification requires large amounts of surfactant to prevent coalescence and improve emulsions lifetime. However, most numerical studies have considered surfactant-free mixtures as models for droplet formation in microchannels, without taking into account the distribution on surface. In this paper, we investigate effects nonuniform coverage microfluidic flow pattern using an extended lattice-Boltzmann model. This study, supported by micro-particle image velocimetry experiments, reveals likelihood uneven during appearance a stagnant cap. The Marangoni effect affects breakup increasing shear rate. According our results, surfactant-rich processes are qualitatively different, such that both capillary number Damköhler should be when modeling generation devices. limitations traditional volume pressure estimation methods determining dynamic interfacial tension also discussed basis simulation results.