The Role of Colloidal Stability in the Formation of Gold Sols

• Published in: Journal of colloid and interface science Vol. 160; no. 2; pp. 511 - 513
• Main Authors: Biggs, Simon, Chow, M.K., Zukoski, Charles F., Grieser, Franz
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.10.1993; Elsevier
• Subjects: 400201 - Chemical & Physicochemical Properties; ADSORPTION; Chemistry; CHLORIDES; CHLORINE COMPOUNDS; Colloidal gels. Colloidal sols; Colloidal state and disperse state; COLLOIDS; DISPERSIONS; ELEMENTS; Exact sciences and technology; General and physical chemistry; GOLD; GOLD CHLORIDES; GOLD COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; METALS; MICROSCOPY; SOLS; SORPTION; SPECTROSCOPY; STABILITY; TRANSITION ELEMENT COMPOUNDS; TRANSITION ELEMENTS; Atomic force microscopy; Gold; Optical spectrometry; Liquid solid interface; Stability; Liquid solid adsorption; Gold Complexes; Citrate; Transition metal; Anionic complex; Transition metal Complexes; Experimental study; Sodium Compounds; Charge density; Chemical reduction; Preparation; Chloro complex; Colloidal sol
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.1993.1430

The stability of gold sols, formed by the reduction of AuCl - 4 with trisodium citrate, was examined as a function of reaction time using optical spectroscopy and direct force measurements performed with an atomic force microscope (AFM). The competitive adsorption of the ions and the effects of each species on the dispersion forces for the sol are examined. Analysis of the data suggests that the AuCl - 4 is adsorbed preferentially at the gold/water interface but, due to its lower charge density, is not as efficient a dispersion agent as the trivalent citrate anion. The use of raw force data from the AFM to attain a qualitative understanding of colloidal phenomena is also demonstrated with this study.