The microrheology of wet forms
- Sandia National Labs., Albuquerque, NM (United States)
- Southern Methodist Univ., Dallas, TX (United States). Dept. of Mathematics
The Kelvin cell is the only known topology for stable, perfectly ordered, dry foams. During topological transitions (T1s) associated with large elastic-plastic deformations, these cells switch neighbors and some faces gain or lose two sides, but the resulting bubbles with different shape are still Kelvin cells. The bubbles in a stable, perfectly ordered. wet foam are not limited to one topology (or even the two described here). The topological transitions considered here result in gain or loss of two dry films per bubble. The transition from Kelvin to RD topology is triggered by films shrinking in area, as in the dry case. However, the reverse transition from RD to Kelvin topology involves a different mechanism--opposite interfaces of an eight-way vertex touch and a new film grows from the point of contact as the foam is compressed. Microrheological analysis based on 2D models of foam structure has been useful preparation for 3D, despite obvious differences between 2D and 3D. Linear elastic behavior is anisotropic for perfectly ordered 3D foams--nonlinear elastic behavior is isotropic for 2D foams with polydisperse hexagonal structure. The shear moduli of a wet Kelvin foam decrease with increasing {phi}--the shear modulus of a wet 2D foam (with three-way Plateau borders) does not depend on {phi} at all. The effective isotropic shear moduli G of perfectly ordered wet foams tend to decrease with increasing {phi} but do not exhibit linear dependence, which may stem from the disorder of real systems.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 249213
- Report Number(s):
- SAND--96-0457C; CONF-960845--3; ON: DE96010329
- Country of Publication:
- United States
- Language:
- English
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