Dissolving Interfaces in Binary Mixtures of Different Density Contrast.
Abstract
We report measurements for the surface tension of the interface between the phases of a cyclohexane and deuterated methanol binary mixture as it dissolves after an increase in temperature which drives the system from a two-phase equilibrium state to a non-equilibrium final state of temperature in the one-phase region of the coexistence diagram. The dynamic interfacial tension was calculated from the measured autocorrelation function obtained using the capillary waves surface light scattering technique. A comparison with the previously reported results( D. H. Vlad and J. V. Maher, The Dissolution of a Liquid Interface), APS March Meeting 1997 obtained for the cyclohexane-methanol mixture shows that the interface of the deuterated mixture (of larger density contrast) dissolves much slower than that of the non-deuterated binary mixture. Possible explanations for these results could involve the gravitational field, pinning the interface and slowing down the dissolution process, or they might involve differences between the dynamic interfacial tension inferred from the capillary wave analysis and the interfacial free energy of interest. A quantitative analysis of the results is a very difficult task since, according to our knowledge, there is no satisfactory theoretical treatment of the problem involving both diffusion and hydrodynamics.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.M2907V