Nano Archive

Discrepancy between different estimates of the hydrodynamic diameter of polymer-coated iron oxide nanoparticles in solution

Regmi, R. and Gumber, V. and Subba Rao, V. and Kohli, I. and Black, C. and Sudakar, C. and Vaishnava, P. and Naik, V. and Naik, R. and Mukhopadhyay, A. and Lawes, G. (2011) Discrepancy between different estimates of the hydrodynamic diameter of polymer-coated iron oxide nanoparticles in solution. Journal of Nanoparticle Research, 13 (12). pp. 6869-6875.

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Abstract

We have synthesized iron oxide nanoparticles coated with a monolayer of dextran, with molecular weights of the polymer between 5 and 670 kDa. Transmission electron microscopy images confirm that the hard core has a crystalline diameter of approximately 12 nm. The hydrodynamic diameters of these coated nanoparticles in solution measured using dynamical light scattering and estimated from magnetic susceptibility studies vary from near 90 nm for the lightest polymer to 140 nm for the heaviest polymer. Conversely, fluorescence correlation spectroscopy measurements yield a diameter of approximately 55 nm for the 15–20 kDa dextran coated nanoparticles, which is consistent with the expected value estimated from the sum of the hard-core diameter and monolayer dextran coating. We discuss the implications of this discrepancy for applications involving polymer-coated magnetic nanoparticles.

Item Type:Article
ID Code:11440
Deposited By:Prof. Alexey Ivanov
Deposited On:05 Jan 2012 09:29
Last Modified:05 Jan 2012 09:42

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