title: Symmetry-breaking transitions and dissociation of two-dimensional Plateau borders.
abstract: We have experimentally studied the dissociation/coalescence of internal Plateau borders (PBs) in simple monolayer bubble clusters, as a result of changing the liquid fraction. At large liquid content, the clusters consist of n bubbles of the same size, symmetrically placed around an internal n-sided PB (n-PB). On decreasing the liquid fraction we observed symmetry-breaking transitions in the 4- and 5-bubble clusters (but not in the 3-bubble cluster), followed by dissociation of the PBs. We used the Surface Evolver to determine the various equilibrium configurations of the corresponding two-dimensional wet clusters and their surface energies. The sequence of 4-bubble cluster configurations observed on varying the liquid fraction correlates qualitatively with that predicted on the basis of Surface Evolver calculations. The same is not true of the 5-bubble cluster.
authors.affiliation: Departamento de Engenharia de Materials and Instituto de Ciência e Engenharia de Materiais e Superfícies, Instituto Superior Técnico, Avenida Rovisco Pais, P-1049-001 Lisbon, Portugal.
authors.forename: M Fátima
authors.initials: MF
authors.lastname: Vaz
authors.forename: M A
authors.initials: MA
authors.lastname: Fortes
authors.forename: P I C
authors.initials: PI
authors.lastname: Teixeira
references.citation: Eur Phys J E Soft Matter. 2003 May;11(1):95-7
references.pmid: 15015091