Gold sol formation mechanisms: Role of colloidal stability

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Journal of Colloid and Interface Science; (United States)

DOI:https://doi.org/10.1006/jcis.1994.1210· OSTI ID:7197533

Chow, M K; Zukoski, C F ^[1]

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1. Univ. of Illinois, Urbana, IL (United States). Dept. of Chemical Engineering

The formation of uniform gold sols produced by the citrate reduction of auric acid is explored as a function of temperature and reagent concentration. As aurate ions are reduced, the reaction medium changes from black to purple to blue before turning deep red. These color changes are shown to result from a decrease in particle size over the course of the reaction. Electrophoretic and titration studies suggest the colloidal properties of the sols result from a combination of van der Waals, electrostatic, and short-range repulsive interaction potentials. Increases in particle surface potential over the course of the reaction are shown to result from competitive adsorption of citrate and aurate ions. A particle growth model incorporating colloidal stability is postulated.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 7197533
• Journal Information: Journal of Colloid and Interface Science; (United States), Journal Name: Journal of Colloid and Interface Science; (United States) Vol. 165:1; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBOXYLIC ACID SALTS
CITRATES
COLLOIDS
DATA
DISPERSIONS
EXPERIMENTAL DATA
GOLD COMPOUNDS
INFORMATION
MATHEMATICAL MODELS
MEASURING METHODS
NUMERICAL DATA
STABILITY
TRANSITION ELEMENT COMPOUNDS