Size and Density Measurement of Core-Shell Si Nanoparticles by Analytical Ultracentrifugation

Published

March 22, 2013

Author(s)

Kanokwan (. Nontapot, Vinayak Rastogi, Jeffrey Fagan, Vytas Reipa

Abstract

Si nanocrystals, terminated with cyclohexane and allylamine, were analyzed using analytical ultracentrifugation (AUC), dynamic light scattering (DLS) and transmission electron microscopy (TEM). We found that AUC yielded equivalent particle size distribution data to other NP characterization techniques, while also providing important information not probed by techniques such as DLS regarding the relative size of the particle core and shell components, and the overall effective particle density. Estimates of particle core and shell dimensions are consistent with particle optical properties within the quantum confinement representation and available theoretical Si nanocrystal models. Measurement of sedimentation velocity in several solvents with the unlike densities presents a way to circumvent the ambiguity of simultaneous fitting of particle density and sedimentation coefficient and allows to significantly reduce the uncertainty in the particle hydrodynamic diameter estimates by finding the effective particle density value.

Citation

Langmuir

Pub Type

Journals

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DOI Link

Keywords

Silicon nanocrystal, core-shell nanoparticles, size measurement, analytical ultracentrifugation, dynamic light scattering

Citation

Nontapot, K. , Rastogi, V. , Fagan, J. and Reipa, V. (2013), Size and Density Measurement of Core-Shell Si Nanoparticles by Analytical Ultracentrifugation, Langmuir, [online], https://doi.org/10.1088/0957 (Accessed March 13, 2025)