title: The order of condensation in capillary grooves.
abstract: We consider capillary condensation in a deep groove of width L. The transition occurs at a pressure p(co)(L) described, for large widths, by the Kelvin equation p(sat) - p(co)(L) = 2σ cosθ/L, where θ is the contact angle at the side walls and σ is the surface tension. The order of the transition is determined by the contact angle of the capped end θcap; it is continuous if the liquid completely wets the cap, and first-order otherwise. When the transition is first-order, corner menisci at the bottom of the capillary lead to a pronounced metastability, determined by a complementary Kelvin equation Δp(L) = 2σ sinθcap/L. On approaching the wetting temperature of the capillary cap, the corner menisci merge and a single meniscus unbinds from the bottom of the groove. Finite-size scaling shifts, crossover behaviour and critical singularities are determined at mean-field level and beyond. Numerical and experimental results showing the continuous nature of condensation for θcap = 0 and the influence of corner menisci on adsorption isotherms are presented.
authors.affiliation: GISC, Departamento de Matemáticas, Universidad Carlos III de Madrid, Madrid, Spain. carlos.rascon@uc3m.es
authors.forename: Carlos
authors.initials: C
authors.lastname: Rascón
authors.forename: Andrew O
authors.initials: AO
authors.lastname: Parry
authors.forename: Robert
authors.initials: R
authors.lastname: Nürnberg
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pozzato
authors.forename: Massimo
authors.initials: M
authors.lastname: Tormen
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bruschi
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Mistura
mesh_terms: D002197:Capillary Action; D003198:Computer Simulation; D008956:Models, Chemical; D044367:Phase Transition; D012212:Rheology / Q000379:methods*; D012996:Solutions / Q000737:chemistry*; D017155:Wettability
chemical_list: D012996:Solutions