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Dynamics of hard sphere colloidal dispersionsOur objective is to perform on homogeneous, fully equilibrated dispersions the full set of experiments characterizing the transition from fluid to solid and the properties of the crystalline and glassy solid. These include measurements quantifying the nucleation and growth of crystallites, the structure of the initial fluid and the fully crystalline solid, and Brownian motion of particles within the crystal, and the elasticity of the crystal and the glass. Experiments are being built and tested for ideal microgravity environment. Here we describe the ground based effort, which exploits a fluidized bed to create a homogeneous, steady dispersion for the studies. The differences between the microgravity environment and the fluidized bed is gauged by the Peclet number Pe, which measures the rate of convection/sedimentation relative to Brownian motion. We have designed our experiment to accomplish three types of measurements on hard sphere suspensions in a fluidized bed: the static scattering intensity as a function of angle to determine the structure factor, the temporal autocorrelation function at all scattering angles to probe the dynamics, and the amplitude of the response to an oscillatory forcing to deduce the low frequency viscoelasticity. Thus the scattering instrument and the colloidal dispersion were chosen such as that the important features of each physical property lie within the detectable range for each measurement.
Document ID
19950008159
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Zhu, J. X.
(Princeton Univ. NJ, United States)
Chaikin, Paul M.
(Princeton Univ. NJ, United States)
Phan, S.-E.
(Princeton Univ. NJ, United States)
Russel, W. B.
(Princeton Univ. NJ, United States)
Date Acquired
September 6, 2013
Publication Date
August 1, 1994
Publication Information
Publication: NASA. Lewis Research Center, Second Microgravity Fluid Physics Conference
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
95N14573
Funding Number(s)
CONTRACT_GRANT: NAG3-1158
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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