title: Shape separation of gold nanoparticles using a pH-responsive amphiphilic dendrimer according to their shape anisotropy distinction.
abstract: We present a novel method for shape-selective separation of nanoparticles in aqueous media utilizing an amphiphilic cationic dendrimer (C18N5) through regulation of the pH of the dispersion medium. This amphiphilic dendrimer (C18N5) bears a poly(amidoamine) dendron with four terminal amine groups and one hydrophobic long alkyl chain, and it can strongly adsorb to the surface of gold nanoparticles at low pH and promote their aggregation at high pH. During aggregation, isotropic NPs with smaller inter-particle contact area have much better solution stability than anisotropic NPs. Therefore, isotropic NPs remain stable in the supernatant, while anisotropic NPs are subject to aggregation and subsequent precipitation. As a result of this simple separation strategy, gold nanoplates with a purity level of 97% (in number density) can be rapidly and conveniently achieved.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloids and Surfaces, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Minjia
authors.initials: M
authors.lastname: Hao
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Aix-Marseille Université, CNRS, Centre Interdisciplinaire de Nanoscience de Marseille, UMR 7325, 163 avenue de Luminy, 13288 Marseille, France.
authors.forename: Ling
authors.initials: L
authors.lastname: Peng
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloids and Surfaces, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jinru
authors.initials: J
authors.lastname: Li
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloids and Surfaces, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Wensheng
authors.initials: W
authors.lastname: Lu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloids and Surfaces, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: jiangl@iccas.ac.cn.
authors.forename: Long
authors.initials: L
authors.lastname: Jiang
mesh_terms: D002412:Cations; D050091:Dendrimers / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission
chemical_list: D002412:Cations; D050091:Dendrimers; D006046:Gold
keywords: Amphiphilic cationic dendrimer; Gold nanoplates; Purification; Separation