Gold nanoparticle supracrystals mechanics under pressure: the role of the soft matrix

TL;DR

This study investigates the mechanical response of gold nanoparticle supracrystals under high pressure, revealing a significant increase in bulk modulus without structural transition up to 12 GPa, highlighting the role of soft ligands.

Contribution

It provides new insights into the pressure-induced mechanical behavior of gold nanoparticle supracrystals and the influence of soft ligand matrices on their properties.

Findings

No structural transition up to 12 GPa

Large increase in bulk modulus under pressure

Ligand matrix significantly affects mechanical response

Abstract

Nanocrystals, used as building blocks, may self-assemble in long-range ordered assemblies socalled supracrystals. Different structures FCC, BCC but also Frank-Kasper phases have been observed and the roles of the soft ligands surrounding the rigid crystalline cores in the self-assembly process is not yet well understood and need further study. The mechanical behavior under hydrostatic pressure of 3D single FCC crystals built by gold nanoparticles has been investigated using HP-SAXS and compared with pure alkane, corresponding to the ligand chain. No structural transition has been observed up to 12 GPa, but a large increase of the supracrystals bulk modulus has been measured.