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Dynamics of dense, charge‐stabilized suspensions of colloidal silica studied by correlation spectroscopy with coherent X‐rays
Author(s) -
Grübel G.,
Abernathy D. L.,
Riese D. O.,
Vos W. L.,
Wegdam G. H.
Publication year - 2000
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889800099994
Subject(s) - dynamic light scattering , diffusion , structure factor , scattering , spectroscopy , colloid , fluorescence correlation spectroscopy , small angle x ray scattering , particle (ecology) , dynamic structure factor , charge (physics) , light scattering , range (aeronautics) , analytical chemistry (journal) , materials science , molecular physics , chemistry , optics , physics , crystallography , thermodynamics , inelastic scattering , nanoparticle , nanotechnology , fluorescence , oceanography , chromatography , quantum mechanics , inelastic neutron scattering , geology , composite material
The dynamics of concentrated, charge‐stabilized colloidal silica suspensions was studied over a wide range of wave‐vectors. The short‐time diffusion coefficient, D(Q), was measured for concentrated suspensions up to their solidification points by photon correlation spectroscopy with coherent X‐rays and compared to free particle diffusion D 0 , studied by Dynamic Light Scattering (DLS) in the dilute case. Small angle X‐ray scattering (SAXS) was used to determine the static structure factor S(Q). D 0 /D(Q) peaks for Q values corresponding to the maximum of the static structure factor showing that the mostly likely density fluctuations decay the slowest. The data allow one to estimate the diffusion coefficient D(Q) in the Q → 0 and Q →∞ limits. Thus, hydrodynamic functions can be derived free from any modeling of the static or dynamic properties. The effects of hydrodynamic interactions on the diffusion coefficient in charge‐stabilized suspensions are presented for volume fractions 0.075 < Φ < 0.28.