title: Gel transition in adhesive hard-sphere colloidal dispersions: the role of gravitational effects.
abstract: The role of gravity in gelation of adhesive hard spheres is studied and a critical criterion developed for homogeneous gelation within the gas-liquid binodal. We hypothesize that gelation by Brownian diffusion competes with phase separation enhanced by gravitational settling. This competition is characterized by the gravitational Péclet number Pe(g), which is a function of particle size, volume fraction, and gravitational acceleration. Through a systematic variation of the parameters, we observe the critical Pe(g) of ∼ 0.01 can predict the stability of gels composed of adhesive hard spheres.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Center for Neutron Science, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Analytical and Systems Research, Arkema Inc., King of Prussia, Pennsylvania 19406, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Fang
authors.affiliation: National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, USA.
authors.forename: Aaron P R
authors.initials: AP
authors.lastname: Eberle
authors.affiliation: División de Ciencias e Ingenierías, Universidad de Guanajuato, Loma del Bosque 103, 37150 León, Mexico.
authors.forename: Ramón
authors.initials: R
authors.lastname: Castañeda-Priego
authors.affiliation: Department of Chemical and Biomolecular Engineering, Center for Neutron Science, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: Norman J
authors.initials: NJ
authors.lastname: Wagner
mesh_terms: D000268:Adhesiveness; D003102:Colloids / Q000737:chemistry*; D006112:Gravitation; D006244:Hardness; D008956:Models, Chemical; D044367:Phase Transition
chemical_list: D003102:Colloids