Cargando…

Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures

Differential centrifugal sedimentation (DCS) is based on physical separation of nanoparticles in a centrifugal field prior to their analysis. It is suitable for resolving particle populations, which only slightly differ in size or density. Agglomeration presents a common problem in many natural and...

Descripción completa

Detalles Bibliográficos
Autores principales: Plüisch, Claudia Simone, Stuckert, Rouven, Wittemann, Alexander
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8072784/
https://www.ncbi.nlm.nih.gov/pubmed/33920635
http://dx.doi.org/10.3390/nano11041027
_version_ 1783683985200644096
author Plüisch, Claudia Simone
Stuckert, Rouven
Wittemann, Alexander
author_facet Plüisch, Claudia Simone
Stuckert, Rouven
Wittemann, Alexander
author_sort Plüisch, Claudia Simone
collection PubMed
description Differential centrifugal sedimentation (DCS) is based on physical separation of nanoparticles in a centrifugal field prior to their analysis. It is suitable for resolving particle populations, which only slightly differ in size or density. Agglomeration presents a common problem in many natural and engineered processes. Reliable data on the agglomeration state are also crucial for hazard and risk assessment of nanomaterials and for grouping and read-across of nanoforms. Agglomeration results in polydisperse mixtures of nanoparticle clusters with multimodal distributions in size, density, and shape. These key parameters affect the sedimentation coefficient, which is the actual physical quantity measured in DCS, although the method is better known for particle sizing. The conversion into a particle size distribution is, however, based on the assumption of spherical shapes. The latter disregards the influence of the actual shape on the sedimentation rate. Sizes obtained in this way refer to equivalent diameters of spheres that sediment at the same velocity. This problem can be circumvented by focusing on the sedimentation coefficient distribution of complex nanoparticle mixtures. Knowledge of the latter is essential to implement and optimize preparative centrifugal routines, enabling precise and efficient sorting of complex nanoparticle mixtures. The determination of sedimentation coefficient distributions by DCS is demonstrated based on supracolloidal assemblies, which are often referred to as “colloidal molecules”. The DCS results are compared with sedimentation coefficients obtained from hydrodynamic bead-shell modeling. Furthermore, the practical implementation of the analytical findings into preparative centrifugal separations is explored.
format Online
Article
Text
id pubmed-8072784
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-80727842021-04-27 Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures Plüisch, Claudia Simone Stuckert, Rouven Wittemann, Alexander Nanomaterials (Basel) Article Differential centrifugal sedimentation (DCS) is based on physical separation of nanoparticles in a centrifugal field prior to their analysis. It is suitable for resolving particle populations, which only slightly differ in size or density. Agglomeration presents a common problem in many natural and engineered processes. Reliable data on the agglomeration state are also crucial for hazard and risk assessment of nanomaterials and for grouping and read-across of nanoforms. Agglomeration results in polydisperse mixtures of nanoparticle clusters with multimodal distributions in size, density, and shape. These key parameters affect the sedimentation coefficient, which is the actual physical quantity measured in DCS, although the method is better known for particle sizing. The conversion into a particle size distribution is, however, based on the assumption of spherical shapes. The latter disregards the influence of the actual shape on the sedimentation rate. Sizes obtained in this way refer to equivalent diameters of spheres that sediment at the same velocity. This problem can be circumvented by focusing on the sedimentation coefficient distribution of complex nanoparticle mixtures. Knowledge of the latter is essential to implement and optimize preparative centrifugal routines, enabling precise and efficient sorting of complex nanoparticle mixtures. The determination of sedimentation coefficient distributions by DCS is demonstrated based on supracolloidal assemblies, which are often referred to as “colloidal molecules”. The DCS results are compared with sedimentation coefficients obtained from hydrodynamic bead-shell modeling. Furthermore, the practical implementation of the analytical findings into preparative centrifugal separations is explored. MDPI 2021-04-17 /pmc/articles/PMC8072784/ /pubmed/33920635 http://dx.doi.org/10.3390/nano11041027 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Plüisch, Claudia Simone
Stuckert, Rouven
Wittemann, Alexander
Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures
title Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures
title_full Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures
title_fullStr Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures
title_full_unstemmed Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures
title_short Direct Measurement of Sedimentation Coefficient Distributions in Multimodal Nanoparticle Mixtures
title_sort direct measurement of sedimentation coefficient distributions in multimodal nanoparticle mixtures
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8072784/
https://www.ncbi.nlm.nih.gov/pubmed/33920635
http://dx.doi.org/10.3390/nano11041027
work_keys_str_mv AT pluischclaudiasimone directmeasurementofsedimentationcoefficientdistributionsinmultimodalnanoparticlemixtures
AT stuckertrouven directmeasurementofsedimentationcoefficientdistributionsinmultimodalnanoparticlemixtures
AT wittemannalexander directmeasurementofsedimentationcoefficientdistributionsinmultimodalnanoparticlemixtures