posted on 2024-10-31, 07:29authored byYingying Cai, Swagato Sarkar, Yuwen Peng, Tobias A. F. König, Philipp Vana
Plasmonic molecules (PMs) composed of polymer-capped
nanoparticles
represent an emerging material class with precise optical functionalities.
However, achieving controlled structural changes in metallic nanoparticle
aggregation at the nanoscale, similar to the modification of atomic
structures, remains challenging. This study demonstrates the 2D/3D
isomerization of such plasmonic molecules induced by a controlled
ultrasound process. We used two types of gold nanoparticles, each
functionalized with hydrogen bonding (HB) donor or acceptor polymers,
to self-assemble into different ABN-type
complexes via interparticle polymer bundles acting as molecular bonds.
Post-ultrasonication treatment significantly shortens these bonds
from approximately 14 to 2 nm by enhancing HB cross-linking within
the bundles. This drastic change in the bond length increases the
stiffness of the resulting clusters, facilitating the transition from
2D to 3D configurations in 100% yield during drop-casting onto substrates.
Our results advance the precise control of PMs’ nanoarchitectures
and provide insights for their broad applications in sensing, optoelectronics,
and metamaterials.