title: Gasous hole closing in a polymer Langmuir monolayer.
abstract: The hole-closing phenomenon is studied in a polymer Langmuir film with coexisting gaseous and liquid phases both as a test of hydrodynamic theories of a two-dimensional fluid embedded in a three-dimensional one and as a means to accurately determine line tension, an important parameter determining size, shape, and dynamics within these and other membrane model systems. The hole-closing curve consists of both a universal linear regime and a history-dependent nonlinear one. Improved experimental technique allows us to explore the origin of the nonlinear regime. The linear regime confirms previous theoretical work and yields a value lambda = (0.69 +/- 0.02) pN for the line tension of the boundary between the gaseous and liquid phases. The observed hole closing also demonstrates that the two-dimensional polymer gas must be taken as having a small, probably negligible elasticity, so that line-tension measurements assuming that both phases are incompressible should be re-evaluated.
authors.affiliation: Department of Physics, Kent State University, Kent, Ohio 44242, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Zou
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bernoff
authors.forename: J Adin
authors.initials: JA
authors.lastname: Mann
authors.forename: James C
authors.initials: JC
authors.lastname: Alexander
authors.forename: Elizabeth K
authors.initials: EK
authors.lastname: Mann
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D006358:Hot Temperature; D007834:Lasers; D045423:Microbubbles; D011312:Pressure
chemical_list: D004129:Dimethylpolysiloxanes; D005740:Gases; C013830:baysilon