title: Size sorting of citrate reduced gold nanoparticles by sedimentation field-flow fractionation.
abstract: Gold nanoparticles (GNPs) have been synthesized through the citrate reduction method; the citrate/gold(III) ratio was changed from 1:1 up to 10:1 and the size of the resulting nanoparticles was measured by sedimentation field-flow fractionation (SdFFF). Experimental data showed that the GNPs size decreases in the ratio range 1:1-3:1 and then increases from 5:1 to 10:1 passing through a plateau region in between, and is almost independent of the precursor solution concentrations. In the zone of minimum diameters the synthetic process does not produce monodispersed GNPs but often multiple distributions, very close in size, are observed as evidenced by the particle size distributions (PSDs) derived from the SdFFF fractograms. UV-vis spectrophotometry, being the most common technique employed in the optical characterization of nanoparticles suspensions, was used throughout this work. A confirmation of the nucleation-aggregation-fragmentation mechanism was inferred from the cross-correlation between UV-vis and SdFFF results.
authors.affiliation: Department of Chemistry, University of Ferrara, via L. Borsari 46, I-44100 Ferrara, Italy. Catia.Contado@unife.it
authors.forename: Catia
authors.initials: C
authors.lastname: Contado
authors.forename: Roberto
authors.initials: R
authors.lastname: Argazzi
mesh_terms: D031521:Fractionation, Field Flow / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size
chemical_list: D006046:Gold