Double layer micellar stabilization of gold nanocrystals by greener ionic liquid 1-butyl-3-methylimidazolium lauryl sulfate

• Published in: Materials letters Vol. 64; no. 9; pp. 1109 - 1112
• Main Authors: Obliosca, Judy M., Arellano, Ian Harvey J., Huang, Michael H., Arco, Susan D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-05-2010
• Subjects: Crystal growth; Ionic liquid; Micelle; Nanoparticle; Crystal growth; Micelle; Nanoparticle; Ionic liquid
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2010.02.029

We report the first synthesis of anisotropic gold nanocrystals (AuNC) prepared by a seeding approach using the greener ionic liquid, 1-butyl-3-methylimidazolium lauryl sulfate, [BMIM] [C
12H
25OSO
3]. Crystal growth was successfully achieved by successive addition of growth solution containing HAuCl
4 and ascorbic acid to 2.5-nm Au seeds. These nanocrystals were stabilized by the ionic liquid via a two layer micellar formation. SEM and TEM results showed Au nanocrystals with particle sizes ranging from 20 to 50
nm. Selected-area electron diffraction (SAED) and PXRD pattern gave indices that correspond to Au nanocrystals. Direct addition of ionic liquid to Au seeds in 3:1 volume ratio afforded the formation of Au nanoparticles. TEM image and UV–vis data revealed the formation of 20–50
nm Au nanocrystals. These results show that the greener ionic liquid, [BMIM] [C
12H
25OSO
3], is a suitable reaction medium for the direct synthesis of larger Au nanoparticles from Au seeds.