Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Structure and Dynamics Studies of Concentrated Micrometer-Sized Colloidal Suspensions



Fan Zhang, Andrew J. Allen, Lyle E. Levine, Jan Ilavsky, Gabrielle G. Long


We present an experimental study of the structural and dynamical properties of concentrated suspensions of a series of different sized polystyrene microspheres dispersed in glycerol for volume fraction concentrations between 10 % and 20 %. The static structure, probed with ultra-small angle X-ray scattering, shows a behavior very similar to that of hard spheres. The equilibrium dynamics is probed with ultra-small angle X-ray scattering - X-ray photon correlation spectroscopy, a new technique that overcomes the limits of visible light scattering techniques imposed by multiple scattering and is suitable for studies of optically opaque materials containing micrometer-sized structures. Contrary to a previous study of a similar, but much smaller nano-colloid system (Lurio et al., Phys. Rev. Lett. 84, 785, (2000)), we found that the intensity autocorrelation functions are better described by a stretched exponential function and microspheres in a concentrated suspension move collectively, rather than behaving as free particles in Brownian motion. We also found that the inverse of the effective diffusion coefficients display a peak with respect to the scattering vector that resembles the peaks in the static structure factors, which indicates that a long-lived, low free-energy state exists. The relaxation time is inversely related to scattering vector, a behavior consistent with models that describe the dynamics in terms of random, local structural arrangements in disordered elastic media.


microstructure charaterization, small-angle X-ray scattering, X-ray photon correlation spectroscopy, colloidal dispersions, particle dynamics


Zhang, F. , Allen, A. , Levine, L. , Ilavsky, J. and Long, G. (2013), Structure and Dynamics Studies of Concentrated Micrometer-Sized Colloidal Suspensions, Langmuir, [online], (Accessed July 16, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created January 6, 2013, Updated October 12, 2021