title: Brownian motion studies of viscoelastic colloidal gels by rotational single particle tracking.
abstract: Colloidal gels have unique properties due to a complex microstructure which forms into an extended network. Although the bulk properties of colloidal gels have been studied, there has been difficulty correlating those properties with individual colloidal dynamics on the microscale due to the very high viscosity and elasticity of the material. We utilize rotational X-ray tracking (RXT) to investigate the rotational motion of component crystalline colloidal particles in a colloidal gel of alumina and decanoic acid. Our investigation has determined that the high elasticity of the bulk is echoed by a high elasticity experienced by individual colloidal particles themselves but also finds an unexpected high degree of rotational diffusion, indicating a large degree of freedom in the rotational motion of individual colloids even within a tightly bound system.
authors: Department of Physics, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA ; Center for Free-Electron Laser Science, Deutsches Elektronensynchrotron , Notkestrasse 85, 22607 Hamburg, Germany.
authors: Mengning
authors: M
authors: Liang
authors: Argonne National Lab , Argonne, IL 60439, USA.
authors: Ross
authors: R
authors: Harder
authors: Department of Physics, University of Illinois at Urbana-Champaign , Urbana, IL 61801, USA ; Centre for Nanotechnology, University College , London WC1H 0AH, England.
authors: Ian K
authors: IK
authors: Robinson
keywords: colloidal gels; rotational X-ray tracking; rotational dynamics