title: Unusual properties of foams at low pressures.
abstract: In addition to a high coarsening rate, foams at low pressures may show special properties. These include a bulk modulus going to zero, a Poisson's ratio approaching zero, and a zero binding energy, implying foam separation into individual bubbles at a critical pressure. We provide examples of calculations made for particular two-dimensional clusters with an ideal gas, which illustrate these features. We also discuss the difficulties in performing experiments at the low pressures at which the unusual properties show up.
authors.affiliation: ICEMS-Instituto de Ciência e Engenharia de Materiais e Superfícies and Departamento de Engenharia de Materiais, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisbon, Portugal.
authors.forename: M A
authors.initials: MA
authors.lastname: Fortes
authors.forename: M Fátima
authors.initials: MF
authors.lastname: Vaz