title: Surfactant-induced postsynthetic modulation of Pd nanoparticle crystallinity.
abstract: Modulation of Pd nanoparticle (NP) crystallinity is achieved by switching the surfactants of different binding strengths. Pd NPs synthesized in the presence of weak binding surfactants such as oleylamine possess polyhedral shapes and a polycrystalline nature. When oleylamine is substituted by trioctylphosphine, a much stronger binding surfactant, the particles become spherical and their crystallinity decreases significantly. Moreover, the Pd NPs reconvert their polycrystalline structure when the surfactant is switched back to oleylamine. Through control experiments and molecular dynamics simulation, we propose that this unusual nanocrystallinity transition induced by surfactant exchange was resulted from a counterbalance between the surfactant binding energy and the nanocrystal adhesive energy. The findings represent a novel postsynthetic approach to tailoring the structure and corresponding functional performance of nanomaterials.
authors.affiliation: Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Yujie
authors.initials: Y
authors.lastname: Wei
authors.forename: Leyi
authors.initials: L
authors.lastname: Zhu
authors.forename: Dongguo
authors.initials: D
authors.lastname: Li
authors.forename: J Samuel
authors.initials: JS
authors.lastname: Jiang
authors.forename: Nenad M
authors.initials: NM
authors.lastname: Markovic
authors.forename: Vojislav R
authors.initials: VR
authors.lastname: Stamenkovic
authors.forename: Shouheng
authors.initials: S
authors.lastname: Sun
mesh_terms: D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D013501:Surface-Active Agents; D010165:Palladium