Title

Interfacial and Bulk Assembly of Anisotropic Gold Nanostructures: Implications for Photonics and Plasmonics

Publication Date

7-16-2020

Department

Chemical and Biological Engineering; Materials Science and Engineering; Neuroscience; Ames Laboratory; Physics and Astronomy

Campus Units

Ames Laboratory, Chemical and Biological Engineering, Materials Science and Engineering, Physics and Astronomy, Neuroscience

OSTI ID+

1664758

Report Number

IS-J 10318

DOI

10.1021/acsanm.0c01643

Journal Title

ACS Applied Nano Materials

Volume Number

3

Issue Number

8

First Page

8216

Last Page

8223

Abstract

We report on the assembly of polymer-grafted nanostructures at the vapor/aqueous interface and in bulk solutions using synchrotron X-ray diffraction methods. Triangular- and octahedral-shaped gold nanostructures are synthesized and grafted with poly(ethylene glycol) (referred to as PEG-AuNTs and PEG-AuNOh, respectively), and their suspensions are manipulated with salts, (poly)electrolytes that induce interpolymer complexation and HCl to achieve organized assemblies. The assemblies at the vapor/liquid interface are explored by X-ray reflectivity and grazing-incidence small-angle X-ray scattering. Results show that PEG-AuNTs and PEG-AuNOh populate the interface, with some degree of orientation with respect to the liquid surface. The resulting assemblies can be tuned by the regulating electrolyte and pH levels of the suspensions. Similar suspension manipulations also induce three-dimensional assemblies that are revealed with solution small-angle X-ray scattering. In addition to controlling the three-dimensional (3D) aggregates by regulating the (poly)electrolytes and pH levels, we show that raising the temperature of the suspensions from 20 to above 50 degrees C induces and even improves the ordering of the assemblies. Our findings provide tools that can be used to assemble and orient anisotropic nanostructures for potential applications in photonics and plasmonics.

DOE Contract Number(s)

AC02-07CH11358; AC02-06CH11357; CHE-1834750

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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