title: Self-assembly of gold nanorods into symmetric superlattices directed by OH-terminated hexa(ethylene glycol) alkanethiol.
abstract: The self-assembly of anisotropic gold nanorods (GNRs) into ordered phases remains a challenge. Herein, we demonstrated the fabrication of symmetric circular- or semicircular-like self-assembled superlattices composed of multilayers of standing GNRs by fine-tuning the repulsive interactions among GNRs. The repulsive force is tailored from electrostatic interaction to steric force by replacing the surface coating of cetyltrimethylammonium bromide (CTAB) (ζ potential of 20-50 mV) with an OH-terminated hexa(ethylene glycol) alkanethiol (here termed as EG(6)OH, ζ potential of -10 mV). The assembly mechanism is discussed via theoretical analyses of the major interactions, and an effective balance between the repulsive steric and attractive depletion interactions is the main driving force for the self-assembly. The real-time observations of solution assembly (UV-vis-NIR absorption spectroscopy) supports the mechanism that we suggested. The superlattices obtained here not only enrich the categories of the self-assembled structures but more importantly deepen the insight of the self-assembly process and pave the way for various potential applications.
authors.affiliation: Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xie
authors.forename: Shengming
authors.initials: S
authors.lastname: Guo
authors.forename: Yinglu
authors.initials: Y
authors.lastname: Ji
authors.forename: Chuanfei
authors.initials: C
authors.lastname: Guo
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Liu
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wu
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
mesh_terms: D006046:Gold / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014835:Volatilization
chemical_list: D006878:Hydroxides; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; D006046:Gold; C031356:hydroxide ion