Monodisperse sub-10 nm gold nanoparticles by reversing the order of addition in Turkevich method - The role of chloroauric acid

Sivaraman, Sankar Kalidas and Kumar, Sanjeev and Santhanam, Venugopal (2011) Monodisperse sub-10 nm gold nanoparticles by reversing the order of addition in Turkevich method - The role of chloroauric acid. In: Journal of Colloid and Interface Science, 361 (2). pp. 543-547.

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Abstract

The Turkevich method for synthesizing gold nanoparticles, using sodium citrate as the reducing agent, is renowned for its ability to produce biocompatible colloids with mean size >10 nm. Here we show that monodisperse gold nanoparticles in the 5-10 nm size range can be synthesized by simply reversing the order of addition of reactants, i.e. adding chloroauric acid to citrate solution. Kinetic studies and electron microscopic characterization revealed that the reactivity of chloroauric acid, initial molar ratio of citrate to chloroauric acid (MR), and reaction mixture pH play an important role in producing monodisperse gold nanoparticles. Reversing the order of addition also enhanced the stabilization of nanoparticles at high MR values. Remarkably, the system exhibits a `memory' of the order of addition, even when the timescale of mixing is much shorter than the timescale of synthesis. (C) 2011 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Publication:	Journal of Colloid and Interface Science
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Citrate;Chloroauric acid speciation;Gold nanoparticles;Order of addition;Turkevich method
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	30 Aug 2011 06:23
Last Modified:	30 Aug 2011 06:23
URI:	http://eprints.iisc.ac.in/id/eprint/39941

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