A Dynamical Model of Molecular Monolayers: Why Tethers Don't Snap

A bola-shaped domain in a Langmuir monolayer at the air/water interface relaxes towards a circular shape under the influence of line tension. The ``tether'' thickens continuously in this process, in marked contrast to the Hele-Shaw and the three-dimensional cases, where hydrodynamic instabilities lead to the tether snapping. A simplified dynamical model allows us use lubrication theory to explain this without incorporating repulsive forces to stabilize the tether in 2D. The model also allows us to give a better estimate of line tensions from the relaxation rate of such monolayer domains. This material is based upon work supported by the National Science Foundation under Grant No.9984304.