Physicochemical investigation of surfactant-coated gold nanoparticles synthesized in the confined space of dry reversed micelles
2006; Elsevier BV; Volume: 98; Issue: 2-3 Linguagem: Inglês
10.1016/j.matchemphys.2005.09.068
ISSN1879-3312
AutoresPietro Calandra, Cristina Giordano, Alessandro Longo, Vincenzo Turco Liveri,
Tópico(s)nanoparticles nucleation surface interactions
ResumoGold nanoparticle/surfactant composites have been synthesized by a novel reduction reaction in the confined space of dry sodium bis(2-ethylhexyl)sulfosuccinate (AOT) or lecithin reversed micelles dispersed in n-heptane and cyclohexane, respectively. The reaction was carried out by adding an opportune amount of anhydrous hydrazine/tetrahydrofuran solution to a suspension of HAuCl4-containing dry reversed micelles dispersed in organic solvent. UV–vis investigation ascertained the formation of stable metal gold nanoparticles and the analysis of FT-IR spectra highlighted the formation of an oriented surfactant monolayer at the nanoparticle surface. Simple evaporation under vacuum of the organic solvent leads to the preparation of very interesting gold nanoparticle/surfactant liquid crystal composites. Such nanocomposites, characterized by WAXS and SAXS, showed the presence of small (radius ∼14 Å) and stable gold nanoparticles dispersed in the surfactant matrix. It has been also emphasized that a simple washing process with ethanol is a suitable method to eliminate the excess of surfactant leaving a novel nanomaterial constituted by gold nanoparticles coated by a monolayer of opportunely oriented surfactant molecules.
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