Deformation and bursting of nonspherical polysiloxane microcapsules in a spinning-drop apparatus.
We analyze the deformation and bursting process of nonspherical organosiloxane capsules in centrifugal fields. Measurements were performed in a commercial spinning-drop tensiometer at different values of tube rotation. A theoretical analysis of the mechanics of initially ellipsoidal elastic shells subjected to centrifugal forces is developed where the deformation of the capsule is predicted as a function of the initial geometry and membrane elastic properties. For different types of organosiloxane membranes the Poisson number varies between 0 and 0.9. This phenomenon points to a considerable reduction of the membrane thickness at the onset of mechanical stress. Membrane-breaking processes always initiated at one of the pole ends of the capsules. Such rupture processes can be interpreted in terms of the derived theoretical model.
Husmann
M
M
Institute of Physical Chemistry, University Essen, Postfach, 45141 Essen, Germany.
Rehage
H
H
Dhenin
E
E
Barthès-Biesel
D
D
D002214:Capsules; D002462:Cell Membrane; D008567:Membranes, Artificial; D008954:Models, Biological; D012833:Siloxanes
D002214:Capsules; D008567:Membranes, Artificial; D012833:Siloxanes