Aggregation-Driven Controllable Plasmonic Transition of Silica-Coated Gold Nanoparticles with Temperature-Dependent Polymer–Nanoparticle Interactions for Potential Applications in Optoelectronic Devices

Abstract

Localized surface plasmon resonance (LSPR) effect relies on the shape, size, and dispersion state of metal nanoparticles and can potentially be employed in many applications such as chemical/biological sensor, optoelectronics, and photocatalyst. While complicated synthetic approaches changing shape and size of nanoparticles can control the intrinsic LSPR effect, here we show that controlling interparticle interactions with silica-coated gold nanoparticles (Au@SiO NPs) is a powerful approach, permitting wide range of optical bandwidth of gold nanoparticles with great stability. The interparticle interactions of Au@SiO NPs are controlled through concentration-, temperature-, and time-dependent polymer-induced interactions. The polymer-induced interactions modulate the state of particle dispersion, resulting an effective plasmonic shift by more than 200 nm. We further explore the microstructure of particle aggregation and explain mechanisms of plasmonic shift based on the results of small-angle X-ray scattering (SAXS) and discrete dipole approximation (DDA) calculation. We show that an effective control of LSPR behavior is now available through trapped aggregation of Au@SiO NPs with temperature variation. We anticipate that the suggested strategy can be employed in many practical applications such as optical bioimaging and optoelectronic devices.

Bisphosphine-Stabilized Gold Nanoclusters with the Crown/Birdcage-Shaped Au11 Cores: Structures and Optical Properties

“…Synthesis and characterization of metal nanoclusters, such as gold nanoclusters, have garnered much attention because of their fascinating structures and potential applications in catalysts, biological imaging, chemical sensing, and optoelectronic devices. − Meanwhile, there are many difficult questions in the synthetic gold nanoclusters, such as the precise control of size and shape as well as the core geometry . Recently, to obtain atomically precise gold nanoclusters, multiple strategies, such as the ligands and coordinating anions, which are used to adjust steric stabilization, electronic structures, and molecular conformations, is dedicated to precisely modify the structures and properties of these nanoclusters. − For example, alkynyl, phosphine, and thiolate are used to control and stabilize gold nanoclusters with determined nuclearity and structures. − All these imply that the optimal selection of ligands may be closely bound up with the controlled structures and stability of gold nanoclusters.…”

Periodic Arrays of Diamond‐Shaped Silver Nanoparticles: From Scalable Fabrication by Template‐Assisted Solid‐State Dewetting to Tunable Optical Properties

“…Yet, in order to use such synthetized nanoparticles, an additional transfer step of the nanoparticles from the jar to the final arrangement on a substrate or within a volume without agglomeration is required, which is not at all straightforward. This step is paramount in the fabrication process to achieve the tailored optical properties of the structure . The direct deposition of nanoparticles on surfaces by oblique angle deposition or pulsed laser deposition fails to fully control the arrangement of the grown nano‐objects.…”

Tailored Colloidal Stability and Rheological Properties of Graphene Oxide Liquid Crystals with Polymer-Induced Depletion Attractions

“…Moreover, the discussions on colloidal interactions of GOs in the preparation step of GO LC are often missing; thus, how polymer induced interactions can change the GO-GO interactions has not been answered. In colloidal science, polymers are frequently employed, as they can change the interparticle interactions driving depletion attractions or steric repulsions. − While addition of nonadsorbing polymers brings purely entropic depletion attractions, addition of adsorbing polymers often accompanies complicated depletion attractions and steric repulsions. − Likewise, the addition of polymer in the GO suspension can also have an equivalent effect on GO–GO interaction as in conventional colloidal solutions. In this study, the microstructure and rheological property of GO aqueous suspensions were investigated in the presence of polymers with varying polymer molecular weights and concentrations.…”