title: Digestive Ripening of Au Nanoparticles Using Multidentate Ligands.
abstract: The efficiency of multidentate ligands as digestive ripening (DR) agents for the preparation of monodisperse Au nanoparticles (NPs) was investigated. This systematic investigation was performed using ligands possessing one, two, or three thiol moieties as ligands/DR agents. Our results clearly establish that among the different ligands, monodentate ligands and the use of temperature in the range of 60-120 °C offer the best conditions for DR. In addition, when DR was carried out at lower temperatures (e.g., 60 °C), the NP size increased as the number of thiol groups per ligand increased. However, in the case of ligands possessing two and three thiol moieties, when they were heated with polydispersed particles at higher temperatures (120 or 180 °C), the etching process dominated, which affected the quality of the NPs in terms of their monodispersity. We conclude that the temperature-dependent strength of the interaction between the ligand headgroup and the NP surface plays a vital role in controlling the final particle sizes.
authors.affiliation: Materials Chemistry Division, National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Puspanjali
authors.initials: P
authors.lastname: Sahu
authors.affiliation: Materials Chemistry Division, National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Jayesh
authors.initials: J
authors.lastname: Shimpi
authors.affiliation: Department of Chemistry, University of Houston , Houston, Texas 77204-5003, United States.
authors.forename: Han Ju
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Chemistry, University of Houston , Houston, Texas 77204-5003, United States.
authors.forename: T Randall
authors.identifier: 0000-0001-9584-8861
authors.initials: TR
authors.lastname: Lee
authors.affiliation: Materials Chemistry Division, National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Bhagavatula L V
authors.identifier: 0000-0002-3115-0736
authors.initials: BL
authors.lastname: Prasad