INTERFACIAL-TENSION IN MISCIBLE 2-FLUID SYSTEMS WITH LINEAR VISCOELASTIC RHEOLOGY

I present observations of interfacial tension between miscible pairs o f silicate liquid and propose a theoretical model that quantitatively accounts for them. Viscoelastic rheology of the liquids permits the es tablishment of gradient stress completely analogous to thermal stress in Maxwell solids; this is expected whenever the time scale of diffusi on is shorter than the Maxwell relaxation time. The existence of gradi ent stress may profoundly affect interface processes during mixing of miscible fluids.