title: Gravitational compression dynamics of charged colloidal crystals.
abstract: We examine the compression of charged colloidal crystals under the influence of gravitational force by monitoring the spatiotemporal variations of Bragg diffraction from the crystal lattice. We use the dilute aqueous dispersions of colloidal silica particles (diameter=216 nm, charge number=733, a particle volume fraction φ=0.06) in the presence of 5-15 μM sodium chloride. The sedimentation profiles of the colloidal crystals along the crystal height are determined by in situ fiber optics reflection spectroscopy. The time evolutions of the sedimentation profiles are calculated by numerical simulations based on a phenomenological continuum model that explicitly incorporates the electrostatic interparticle interactions. The simulation results correctly describe the experiments at sufficiently high ionic strength.
authors.affiliation: Faculty of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe, Mizuho, Nagoya, Aichi 467-8603, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Murai
authors.forename: Tohru
authors.initials: T
authors.lastname: Okuzono
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Akiko
authors.initials: A
authors.lastname: Toyotama
authors.forename: Junpei
authors.initials: J
authors.lastname: Yamanaka
mesh_terms: D003102:Colloids / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization; D006112:Gravitation; D007700:Kinetics; D009994:Osmolar Concentration; D010316:Particle Size; D012822:Silicon Dioxide / Q000032:analysis / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D055672:Static Electricity; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D014867:Water; D012965:Sodium Chloride; D012822:Silicon Dioxide