Collapse dynamics of smectic-A bubbles

Deep Holes in Free-Standing Smectic C Films

“…Then, the emerging holes spread with a very high velocity (well above 100 μm/s) to partially compensate the surface area changes. Partially, the film area expansion is also compensated by shape changes of the meniscus, opposite to those described in the film area reduction experiments of Caillier and Oswald [7] (the menisci are stretched). Since the material is in the tilted smectic phase, a transient variation of the tilt angle can also contribute to compensate changes of the supporting frame geometry.…”

“…The dislocation mobility was determined to be of the order of 5·10 −8 m 2 s/kg. Later, Caillier and Oswald [7] studied the collapse of half-spherically smectic films that were initially deformed by a pressure difference between the two sides of the film. After a pressure drop on the concave side of the film, the hemisphere collapsed to a flat film, thereby reducing its area.…”

Freely Floating Smectic Films

“…[12] Of particular interest is the investigation of the dynamics of inclusions in such films, [13] which allows the elucidation of details of the dynamics of 2D fluids and membranes. [46,47] The study of Caillier and Oswald [39] is particularly relevant for the present study, because it relates film area reductions to reorganization processes of smectic layers in the film. In most of these experiments, which were performed with macroscopic bubbles in the radius range between several hundred micrometers and several centimeters, orientational elastic forces and director fields become irrelevant in comparison to surface forces.…”

“…[39] They observed the formation of islands on smectic films after the film surface was rapidly shrunk. The formation of islands (excess smectic layers) during the collapse of smectic bubbles in the presence of a meniscus has been discussed by Caillier and Oswald.…”

“…In technological processes such as coating, or spraying of liquids, particularly for aerosols, the rupture dynamics of thin bubbles can play a significant role. [28][29][30][31][32] Smectic bubbles in air, supported by a capillary, [33][34][35][36][37][38][39][40][41][42] in foams, [43] or on a flat surface [44,45] have been studied. Surface tension measurements, [34,37] electric field effects [35,45] and gas permeation through thin films [38,44] were among the topics of interest.…”