Real-Time Modeling of Volume and Form Dependent Nanoparticle Fractionation in Tubular Centrifuges

Abstract

A dynamic process model for the simulation of nanoparticle fractionation in tubular centrifuges is presented. Established state-of-the-art methods are further developed to incorporate multi-dimensional particle properties (traits). The separation outcome is quantified based on a discrete distribution of particle volume, elongation and flatness. The simulation algorithm solves a mass balance between interconnected compartments which represent the separation zone. Grade efficiencies are calculated by a short-cut model involving material functions and higher dimensional particle trait distributions. For the one dimensional classification of fumed silica nanoparticles, the numerical solution is validated experimentally. A creation and characterization of a virtual particle system provides an additional three dimensional input dataset. Following a three dimensional fractionation case study, the tubular centrifuge model underlines the fact that a precise fractionation according to particle form is extremely difficult. In light of this, the paper discusses particle elongation and flatness as impacting traits during fractionation in tubular centrifuges. Furthermore, communications on separation performance and outcome are possible and facilitated by the three dimensional visualization of grade efficiency data. Future research in nanoparticle characterization will further enhance the models use in real-time separation process simulation.

Multidimensional Separation by Magnetic Seeded Filtration: Theoretical Study

“…Naturally, this concept permeates all areas of particle technology, including solid-liquid separation: For one, separation processes are required to operate on multiple particle properties simultaneously [5,6]. Additionally, the description of the separation result-traditionally given via the size-dependent grade efficiency T(d)-must be further developed to account for the multidimensional nature of particle systems [7,8].…”

Size and Shape Selective Classification of Nanoparticles

“…Anion-exchange chromatography was used to classify gold clusters < 2 nm, and clusters consisting of 10, 15, 25 and 29 gold atoms, respectively, were isolated as single components [3]. Centrifuges providing sufficiently high centrifugal forces (g-value) to separate nanoparticles < 100 nm at a scale of some hundreds of milliliters or even at liter scale become now available [23][24][25]. The material-specific classification of nanoparticles 20-100 nm in diameter can be achieved via magnetic field-assisted methods like porous ferromagnetic membranes [26] or magnetic field chromatography [27] but require either magnetic nanoparticles or a selective binding of magnetic particles to the desired nanoparticle fraction.…”

Multidimensional Separation by Magnetic Seeded Filtration: Experimental Studies

“…Thus, the separation of particles with an array of defined properties usually requires the series connection of different separation apparatus, leading to inefficient processes and increased energy consumption. Therefore, the identification of multidimensional separation techniques that are able to separate according to several particle features simultaneously is an active field of current research [18][19][20][21].…”