Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich-Frens method

Zabetakis, Kara and Ghann, William E and Kumar, Sanjeev and Daniel, Marie-Christine (2012) Effect of high gold salt concentrations on the size and polydispersity of gold nanoparticles prepared by an extended Turkevich-Frens method. In: GOLD BULLETIN, 45 (4). pp. 203-211.

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Abstract

The Turkevich-Frens synthesis starting conditions are expanded, ranging the gold salt concentrations up to 2 mM and citrate/gold(III) molar ratios up to 18:1. For each concentration of the initial gold salt solution, the citrate/gold(III) molar ratios are systematically varied from 2:1 to 18:1 and both the size and size distribution of the resulting gold nanoparticles are compared. This study reveals a different nanoparticle size evolution for gold salt solutions ranging below 0.8 mM compared to the case of gold salt solutions above 0.8 mM. In the case of Au3+]<0.8 mM, both the size and size distribution vary substantially with the citrate/gold(III) ratio, both displaying plateaux that evolve inversely to Au3+] at larger ratios. Conversely, for Au3+]>= 0.8 mM, the size and size distribution of the synthesized gold nanoparticles continuously rise as the citrate/gold(III) ratio is increased. A starting gold salt concentration of 0.6 mM leads to the formation of the most monodisperse gold nanoparticles (polydispersity index<0.1) for a wide range of citrate/gold(III) molar ratios (from 4:1 to 18:1). Via a model for the formation of gold nanoparticles by the citrate method, the experimental trends in size could be qualitatively predicted:the simulations showed that the destabilizing effect of increased electrolyte concentration at high initial Au3+] is compensated by a slight increase in zeta potential of gold nanoparticles to produce concentrated dispersion of gold nanoparticles of small sizes.

Item Type:	Journal Article
Publication:	GOLD BULLETIN
Publisher:	SPRINGER HEIDELBERG
Additional Information:	Copyright for this article belongs to SPRINGER HEIDELBERG, GERMANY
Keywords:	Gold nanoparticles;Synthesis;Citrate reduction;High concentration
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	31 Dec 2012 07:23
Last Modified:	31 Dec 2012 07:23
URI:	http://eprints.iisc.ac.in/id/eprint/45605

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