Centrifugation equilibrium for spheres and spherocylinders

L. S F Martins, F. W. Tavares, R. P. Peçanha, M. Castier

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The centrifugation equilibrium problem is formulated and solved using a new procedure in which the specified variables are the temperature, system volume, particle dimensions and concentrations, angular speed, cell length, and cell distance from the rotation axis. As a result, we obtain the concentration profiles for all types of particles present in the system, which are considered to be immersed in a fluid. The particles are modeled as hard nonattractive spherocylinders using an equation of state, but the procedure is not restricted to any geometrical shape, and can be used with any equation of state available. The fluid is treated as a continuous medium, responsible for centrifugal buoyancy. We make calculations for colloidal suspensions of silica, often used for separations in biotechnology. Results are in good agreement with experiments and show excellent agreement in comparison with Monte Carlo simulations. Our calculations also predict focusing and shifting phenomena that have been experimentally observed in separations of fine particles.

Original languageEnglish
Pages (from-to)360-367
Number of pages8
JournalJournal of Colloid and Interface Science
Volume281
Issue number2
DOIs
Publication statusPublished - 15 Jan 2005
Externally publishedYes

Fingerprint

Centrifugation
Equations of state
Fluids
Biotechnology
Buoyancy
Silicon Dioxide
Suspensions
equations of state
Silica
biotechnology
fluids
cells
buoyancy
colloids
Experiments
silicon dioxide
Temperature
profiles
simulation
temperature

Keywords

  • Centrifugation
  • Colloidal suspensions
  • Equations of state
  • Equilibrium
  • Spheres
  • Spherocylinders

ASJC Scopus subject areas

  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry
  • Surfaces and Interfaces

Cite this

Centrifugation equilibrium for spheres and spherocylinders. / Martins, L. S F; Tavares, F. W.; Peçanha, R. P.; Castier, M.

In: Journal of Colloid and Interface Science, Vol. 281, No. 2, 15.01.2005, p. 360-367.

Research output: Contribution to journalArticle

Martins, L. S F ; Tavares, F. W. ; Peçanha, R. P. ; Castier, M. / Centrifugation equilibrium for spheres and spherocylinders. In: Journal of Colloid and Interface Science. 2005 ; Vol. 281, No. 2. pp. 360-367.
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