title: Spacer-mediated synthesis of size-controlled gold nanoparticles using geminis as ligands.
abstract: We report a new methodology for the size-controlled aqueous synthesis of gold nanoparticles using geminis with different spacers as ligands. Geminis possess a unique structure in which two hydrophobic chains and two polar headgroups are combined via a spacer. We herein demonstrate that the spacer can be used as a tool to control particle size when geminis are used as ligands for gold nanoparticles. Varying the spacer length of geminis yields facile control over the size and size distribution of nanoparticles. For the 18-s-18-capped gold nanoparticles, FTIR and TGA experiments indicate that the geminis form bilayers on the surface of gold nanoparticles, which serve as templates that control the formation of nanoparticles. The smallest particles are obtained with a moderate spacer length (s = 8) because in that case the gemini bilayers interdigitate to the fullest degree to reach the maximum chain-chain interaction, thus yielding the most compact coating on the surface of gold nanoparticles. This work provides a new approach to the size control of nanoparticles.
authors.affiliation: College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Manli
authors.initials: M
authors.lastname: Guo
authors.forename: Zhou
authors.initials: Z
authors.lastname: Nie
authors.forename: Jinbin
authors.initials: J
authors.lastname: Yuan
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D002117:Calcitriol / Q000031:analogs & derivatives* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008024:Ligands; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D010316:Particle Size; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: C411462:1,25-dihydroxy-21-(3-hydroxy-3-methylbutyl)vitamin D(3); D008024:Ligands; D013501:Surface-Active Agents; D006046:Gold; D002117:Calcitriol