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Particle Sedimentation Behaviors in a Density Gradient

  • Pengsong Li
Chapter
Part of the SpringerBriefs in Molecular Science book series (BRIEFSMOLECULAR)

Abstract

Density gradient centrifugation, as an efficient separation method, is widely used in the purification of nanomaterials including zero, one-, and two-dimensional nanomaterials, such as FeCo@C nanoparticles, gold nanoparticles, gold nanobar, graphene, carbon nanotubes, hydrotalcite, zeolite nanometer sheet (the examples can be found in Chap.  5). Each system needs separation parameter optimization, which comes from tremendous research experiments. When particles are put on the top of density gradient medium, they will have a definite settling rate under centrifugal force (Fc) [1], which is influenced by their net density, size, and shape. In a sufficiently intense centrifugal field, the particle motion held quietly free from gravity and vibration [2]. This is the principle of the density gradient ultracentrifuge. Based on the above principle, we discussed the particle sedimentation behaviors and built the kinetic equation in a density gradient media. The kinetic equation could apply to zero, one-, and two-dimensional nanomaterials, within its variation form accordingly. We found that the separation parameters could be optimized based on the kinetic equation. A MATLAB program was further developed to simulate and optimize the separation parameters. The calculated best parameters could be deployed in practice to separate given nanoparticles successfully.

Keywords

Density gradient centrifugation Sedimentation mechanism Sedimentation kinetics Mathematical model Separation parameters Optimization calculation 

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Copyright information

© The Author(s) 2018

Authors and Affiliations

  • Pengsong Li
    • 1
  1. 1.State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical TechnologyBeijingChina

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