THE MARANGONI EFFECT AND ENHANCED OIL-RECOVERY PART-2 - INTERFACIAL-TENSION AND DROP INSTABILITY

A computer-based method is described for the determination of the inte rfacial tension between pendant and sessile drops in a surrounding con tinuous phase. This has been used to determine the effect on interfaci al tension of increasing amounts of aliphatic alcohols, from methanol up to n-octanol, equilibrated between a. hydrocarbon solvent (Shellsol ) and water. The results indicated large decreases in interfacial tens ion, with n-butanol, followed by n-propanol giving the greatest reduct ion. Measurements were also made of the rate of change of interfacial tension during the mass transfer of 2.5% of the alcohols between phase s. Changes were observed for all alcohols from ethanol to n-pentanol, the effect being greatest for transfer into water drops and out of sol vent drops. Application of the linear stability theory of Sorensen to these results failed to predict the observed instability for transfer into solvent drops.