TY - JOUR
T1 - Effect of surfactants on the thermocapillary migration of a concentric compound drop
AU - Borhan, A.
AU - Haj-Hariri, H.
AU - Nadim, A.
N1 - Funding Information:
This work was partially supported by a grant from the Engineering Foundation to A.B., by a NSF grant to H.H., and by a grant from the Chevron Oil Field Research Company to A.N. All of the above support is gratefully acknowledged.
PY - 1992/3/15
Y1 - 1992/3/15
N2 - The quasi-steady thermocapillary motion of a concentric compound drop in the presence of an insoluble surfactant and an externally imposed constant temperature gradient is examined under conditions of negligible convective transport of momentum and energy. Surface tension is assumed to depend much more weakly on surfactant concentration than on temperature. For this case, the surface concentrations of surfactant are found exactly for all Peclet numbers, confirming the intuitively expected result that the surfactant tends to accumulate near the low temperature sides of the inner and outer drops. This, in turn, results in a decrease in the terminal migration velocities of the drops. The effect of surfactant on the shape of the inner and outer drops is also determined for small capillary numbers.
AB - The quasi-steady thermocapillary motion of a concentric compound drop in the presence of an insoluble surfactant and an externally imposed constant temperature gradient is examined under conditions of negligible convective transport of momentum and energy. Surface tension is assumed to depend much more weakly on surfactant concentration than on temperature. For this case, the surface concentrations of surfactant are found exactly for all Peclet numbers, confirming the intuitively expected result that the surfactant tends to accumulate near the low temperature sides of the inner and outer drops. This, in turn, results in a decrease in the terminal migration velocities of the drops. The effect of surfactant on the shape of the inner and outer drops is also determined for small capillary numbers.
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U2 - 10.1016/0021-9797(92)90442-O
DO - 10.1016/0021-9797(92)90442-O
M3 - Article
AN - SCOPUS:5244372435
SN - 0021-9797
VL - 149
SP - 553
EP - 560
JO - Journal of Colloid And Interface Science
JF - Journal of Colloid And Interface Science
IS - 2
ER -