Gold clay from self-assembly of 2D microscale nanosheets

Abstract

Nature has always demonstrated incredible ability to create amazing materials such as soft clay which are built from nanoplatelet packing structures. It is challenging to produce artificial clays owing to the difficulty in obtaining large volume fractions of nanoplatelets and the lack of structural control in layer-by-layer packing. Here, single-crystalline Au nanosheets are synthesized by controlled growth in the bilayer membranes of succinic acid surfactants. Then, a self-assembly strategy is used to make {111}-oriented gold nanostructures at the liquid −liquid interface. The stiffness of the nanosheet assemblies are six orders of magnitude softer than bulk gold. The Au nanosheet aggregates show high plasticity and deformable into macroscale free-standing metallic architectures. They show a stress/strain-dependent conductivity owing to morphological changes. Our study provides valuable insights on the chemical synthesis of 2D nanostructures as well as for the self-assembly strategy on fabrication of mouldable metals for producing free-standing metallic architectures with microscale resolutions.

Lateral Growth of Uniformly Thin Gold Nanosheets Facilitated by Two-Dimensional Precursor Supply

“…Since they can decrease the thickness down to the nanometer scale, the obtained nanosheets frequently exhibit the various nanosize effects. Anisotropic growth of materials with cubic lattices occurs in some specific circumstances; the growth inhibition of a certain crystal plane − and the priority growth on a template − can give fcc metal nanosheets several nanometer thicknesses. Generally, chemical specificity drives the anisotropic growth.…”

“…Generally, chemical specificity drives the anisotropic growth. For example, gold nanosheets (AuNSs) with high conductivity, high catalytic performance, and unique surface plasmon polariton features have been synthesized at liquid–liquid, gas–liquid, solid–liquid, and gas–solid interfaces. They can be applied to electronics, biosensors, and plasmonics .…”

Wet-chemical synthesis of two-dimensional metal nanomaterials for electrocatalysis

“…utilized the dodecenylsuccinic acid bilayers as the soft template for the controlled growth of {111}-oriented fcc Au nanosheets (Fig. 4 d) at the liquid/liquid interface [ 82 ]. Zhu et al.…”

Organic-free growth of gold nanosheets inside 3D bacterial cellulose as highly efficient and robust antibacterial biopolymers

“…The antibacterial abilities of Au nanomaterials are closely related to the size, dispersity, and surface states which needs thorough analysis and investigation [ 13 ]. However, the morphological control of 2D gold nanosheets (AuNSs) and its effect on the antibacteria have not been extensively studied [ 19 , 45 ]. In particular, the following issues will be addressed: (1) whether the 2D surface-clean Au structures can be synthesized inside 3D bacterial cellulose, (2) whether the Au modified BC biopolymers have outstanding antibacterial activities.…”