TY - JOUR
T1 - Surfactant effects on buoyancy-driven viscous interactions of deformable drops
AU - Rother, Michael A.
AU - Zinchenko, Alexander Z.
AU - Davis, Robert H.
PY - 2006/7/20
Y1 - 2006/7/20
N2 - Buoyancy-driven interactions of two deformable drops with a bulk-insoluble, nonionic surfactant are studied with a curvatureless boundary-integral algorithm. At moderate drop-to-medium viscosity ratios with a linear equation of state, the surfactant causes breakup of the larger drop to become dominant over breakup of the smaller drop at O (0.1) values of the dimensionless gas constant β for a surface Péclet number P es of 100. For P es ≤ 10, the surfactant has little effect on breakup for β ≤ 0.2. For P es = 1000, critical horizontal offsets for breakup of the larger drop exceed those for breakup of the smaller drop at β = O (0.01). The influence of surfactant on the deformation and breakup of the smaller drop increases when it becomes closer in size to that of the larger drop. Surfactant effects are less significant when the drop-to-medium viscosity ratio is greater than unity. For the case of bubbles, at P es = 100, the surfactant is swept to the trailing edges early in the trajectories and leads to cusp formation at β = O (0.01).
AB - Buoyancy-driven interactions of two deformable drops with a bulk-insoluble, nonionic surfactant are studied with a curvatureless boundary-integral algorithm. At moderate drop-to-medium viscosity ratios with a linear equation of state, the surfactant causes breakup of the larger drop to become dominant over breakup of the smaller drop at O (0.1) values of the dimensionless gas constant β for a surface Péclet number P es of 100. For P es ≤ 10, the surfactant has little effect on breakup for β ≤ 0.2. For P es = 1000, critical horizontal offsets for breakup of the larger drop exceed those for breakup of the smaller drop at β = O (0.01). The influence of surfactant on the deformation and breakup of the smaller drop increases when it becomes closer in size to that of the larger drop. Surfactant effects are less significant when the drop-to-medium viscosity ratio is greater than unity. For the case of bubbles, at P es = 100, the surfactant is swept to the trailing edges early in the trajectories and leads to cusp formation at β = O (0.01).
KW - Bubbles
KW - Drops
KW - Surfactants
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U2 - 10.1016/j.colsurfa.2005.11.086
DO - 10.1016/j.colsurfa.2005.11.086
M3 - Article
AN - SCOPUS:33744513949
VL - 282-283
SP - 50
EP - 60
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
SN - 0927-7757
ER -