Year: 2000
Type: article
Abstract: In this paper we first develop an approximate theory for the leading order concentration dependence of the sedimentation coefficient for rodlike colloids/polymers/macromolecules. To first order in volume fraction φ of rods, the sedimentation coefficient is written as 1+αφ. For large aspect ratios L/D (L is the rod length, D its thickness) α is found to vary like ∝(L/D)2/ln(L/D). This theoretical prediction is compared to experimental results. Then, experiments on fd virus are described, both in the isotropic and nematic phase. First-order in concentration results for this very long and thin (semiflexible) rod are in agreement with the above-mentioned theoretical prediction. Sedimentation profiles for the nematic phase show two sedimentation fronts. This result indicates that the nematic phase becomes unstable with the respect to isotropic phase during sedimentation.
Source: The Journal of Chemical Physics
DOI: 10.1063/1.1308107
Authors: Z. Dogic, A. P. Philipse, S. Fraden, J. K. G. Dhont
Institutions: Brandeis University, Utrecht University, Forschungszentrum Jülich
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funder: Division of Materials Research
OpenAlex ID: W2146746172