From Molecular‐Level Organization to Nanoscale Positioning: Synergetic Ligand Effect on the Synthesis of Hybrid Nanostructures

Abstract

A key challenge in advancing the design of hybrid nanostructures (HNs) lies in the difficulty in mastering the principle of selected hybrid formation, which is complicated not only by the size and shape variations of nanoparticles but also by the interfacial phenomena associated with surface ligands. Here this study elaborates the formation mechanism of HNs by a combined experimental and theoretical study employing multiscale simulations and shows how molecular information encoded on particle surface can be transferred into distinct composite patterns. The emergence of different HNs is found to be not only related to ligand binding strengths affecting the reaction kinetics but also the ligand-ligand interactions responsible for phase segregation. Unexpectedly, the sulfidation of Ag nanoparticles co-stabilized by citrate/ gallic acid with different molar ratios constantly produces heterodimers with faster reaction rate than the formation of core-shell structures when they are solely coated by citrate or gallic acid. The surprising result originates from the phase separation of two short surface ligands with large contrast in binding strengths as indicated by photoluminescence spectra and supported by the dissipative particle dynamics simulations. Hierarchical HNs consisting of a heterodimer shell with built-in hot spots can be further synthesized using Au@Ag core-shell particles with mixed surface layers.

Self‐Limiting Assembly of Au Nanoparticles Induced by Localized Dynamic Metal‐Phenolic Interactions

“…In our previous work, we showed that a possible phase separation of SC and TA on the surface of Ag NPs may exist as confirmed by molecular dynamics simulations. [5] Here we postulate that similar phenomena may occur here considering both the metallic nature of Au and Ag NPs and their comparable surface structures. [51] We investigate such possible phase separation by photoluminescence (PL) spectra thanks to the emission properties of TA.…”

“…Such ligand combination ensures the synthesis of uniformly small sized Au NPs, similar with our previous work on the synthesis of Ag NPs. [ 5 ] Raman spectroscopy is used to confirm the presence of TA as a competitive ligand for Au NPs (Figure 1b). Compared with SC‐Au, Au NPs synthesized by using both SC and TA (SC,TA‐Au) show multiple characteristic peaks centered around 1599, 1584, 1529, 470, 432 and 395 cm –1 that can be associated with aromatic stretching, deformation, torsion and bending.…”

“…Directed assembly of metallic nanoparticles (NPs) such as Au NPs has attracted so much attention due to its great potential for modulating localized surface plasmon resonance (LSPR) through interparticle coupling. [1][2][3][4][5][6][7] Various Au NP superstructures such as chains, [8,9] sheets [10,11] and 3D assemblies [12,13] have been established by deliberately controlling the interparticle interactions [14][15][16] or using polymer templates. [17][18][19] Interestingly, the ability to avoid the deep trapping state by adjusting the interaction potential has allowed the reversible assembly of Au NPs attractive for stimuli-responsive applications including sensing [20] and drug delivery.…”

Supraparticles: Functionality from Uniform Structural Motifs

“…A recent, alternative approach to achieve specificity is the incorporation of defined chemical interactions between molecules on the surface of the particles. For example, Xiang et al directed the formation of metal–semiconductor heterodimers by changing the composition of the citric/gallic acid ligand layer . Click chemistry has been used to connect Janus particles into linear assemblies .…”

Sustainable, Naringenin-Based Thermosets Show Reversible Macroscopic Shape Changes and Enable Modular Recycling

“…From the viewpoint of polymer chemistry, transesterification, 3−5 Diels−Alder reactions, 6,7 and condensation 8 are commonly used for the synthesis of the thermosets. Recently, more elaborate chemical reactions have also been explored involving transcarbamoylation, 9,10 transcarbonation, 11 thiol−ene reaction, 12,13 transalkylation, 14,15 trithiocarbonate exchange, 16 boronate exchange, 17−19 and olefin metathesis. 20,21 Such polymers have been mainly introduced as vitrimers, 22 or covalent adaptable networks, 23 and have been applied to the environmental fields.…”