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arXiv · 2303.05257

Analysis and optimization of a multicascade method for the size fractionation of poly-dispersed particle systems via sedimentation or centrifugation

Heng Li·Lucas Beetsma·Suriya Prakash·Maurice Mikkers·Lorenzo Botto
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Abstract

Sedimentation and centrifugation can be used to sort particles by size, using a multistep (multicascade) method in which particles in the sediment are removed and the content of the supernatant is processed again, repeating the cycle several times. This paper proposes a theoretical analysis of this process, based on a one-dimensional model, with a view to identify parameters that are optimal to obtain a relatively monodispersed suspension, starting from a log-normal particle size distribution. We found that a rational choice of the sedimentation/centrifugation time enables to control the amount of particles outside of the desired size range (impurities). Surprisingly, the multistep method does not converge, as multiple steps are worse than 2 steps. Band sedimentation, in which a particle-rich layer is overlaid on clear fluid, offers substantial benefits in terms of impurity reduction with respect to starting from a completely mixed situation. An application to graphene fractionation is discussed.

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Heng Li, Lucas Beetsma, Suriya Prakash, Maurice Mikkers, Lorenzo Botto. 2023-03-09. Analysis and optimization of a multicascade method for the size fractionation of poly-dispersed particle systems via sedimentation or centrifugation. https://arxiv.org/abs/2303.05257

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