title: Characterization of nanocrystalline CdSe by size exclusion chromatography.
abstract: High-performance size exclusion chromatography (HPSEC) is a powerful tool for probing the size and size distribution of complex materials. Here we report its application to the analysis of cadmium selenide nanocrystals produced in organic solvents. If nanocrystal-column interactions are minimized, this method provides an accurate measure of nanocrystal hydrodynamic diameter directly in solution; such information is complementary to TEM in that it can measure the thickness of various capping agents. While the resolution of single-pass HPSEC is limited to 1 nm, we show here that recycling size exclusion chromatography can be applied to assess the fine details of a sample's distribution. Finally, semiconductor nanocrystals can be made a variety of shapes whose optical characteristics are difficult to distinguish. HPSEC can be applied to the general problem of shape separations which we demonstrate with a tetrapod material.
authors.affiliation: Department of Chemistry, Rice University, MS-60 6100 Main Street, Houston, Texas 77005, USA.
authors.forename: Karl M
authors.initials: KM
authors.lastname: Krueger
authors.forename: Ali M
authors.initials: AM
authors.lastname: Al-Somali
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Falkner
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Colvin
mesh_terms: D019187:Cadmium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D002138:Calibration; D002850:Chromatography, Gel / Q000379:methods*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D018036:Selenium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012666:Semiconductors; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; C058667:cadmium selenide