title: Bridging transitions for spheres and cylinders.
abstract: We study bridging transitions between spherically and cylindrically shaped particles (colloids) of radius R separated by a distance H that are dissolved in a bulk fluid (solvent). Using macroscopics, microscopic density-functional theory, and finite-size scaling theory, we study the location and order of the bridging transition and also the stability of the liquid bridges, which determines spinodal lines. The location of the bridging transitions is similar for cylinders and spheres, so that at bulk coexistence, for example, the distance H_{b} at which a transition between bridged and unbridged configurations occurs is proportional to the colloid radius R. However, all other aspects, particularly the stability of liquid bridges, are very different in the two systems. Thus, for cylinders the bridging transition is typically strongly first-order, while for spheres it may be first-order, critical, or rounded as determined by a critical radius R_{c}. The influence of thick wetting films and fluctuation effects beyond mean field are also discussed in depth.
authors.affiliation: Department of Physical Chemistry, Institute of Chemical Technology, Prague, 166 28 Praha 6, Czech Republic and Laboratory of Aerosols Chemistry and Physics, Institute of Chemical Process Fundamentals, Academy of Sciences, 16502 Prague 6, Czech Republic.
authors.forename: Alexandr
authors.initials: A
authors.lastname: Malijevský
authors.affiliation: Department of Mathematics, Imperial College London, London SW7 2BZ, United Kingdom.
authors.forename: Andrew O
authors.initials: AO
authors.lastname: Parry