Creating two self-assembly micro-environments to achieve supercrystals with dual structures using polyhedral nanoparticles

Abstract

Organizing nanoparticles into supercrystals comprising multiple structures remains challenging. Here, we achieve one assembly with dual structures for Ag polyhedral building blocks, comprising truncated cubes, cuboctahedra, truncated octahedra, and octahedra. We create two micro-environments in a solvent evaporation-driven assembly system: one at the drying front and one at the air/water interface. Dynamic solvent flow concentrates the polyhedra at the drying front, generating hard particle behaviors and leading to morphology-dependent densest-packed bulk supercrystals. In addition, monolayers of nanoparticles adsorb at the air/liquid interface to minimize the air/liquid interfacial energy. Subsequent solvent evaporation gives rise to various structurally diverse dual-structure supercrystals. The topmost monolayers feature distinct open crystal structures with significantly lower packing densities than their densest-packed supercrystals. We further highlight a 3.3-fold synergistic enhancement of surface-enhanced Raman scattering efficiency arising from these dual-structure supercrystals as compared to a uniform one.

Re-Potentiation of β-Lactam Antibiotic by Synergistic Combination with Biogenic Copper Oxide Nanocubes against Biofilm Forming Multidrug-Resistant Bacteria

“…The asymmetric peak of CuO NPs was confirmed by the presence of a peak at 590 cm –1 [58]. The high packing efficiency of self-assembled nanocubes was supported in earlier studies [59]. Nanocubes with high packing density are preferable for drug delivery and interaction with cells and biomolecules [60].…”

Patchy Nanoparticle Synthesis and Self-Assembly

“…Consequently, although core nanoparticles still matter, "patchiness" can completely alter the interaction dynamics and govern the final superlattice structures. The decades of extensive studies on conventional nanoparticles without patches have revealed the factors determining interaction between nanoparticles and their packing behavior, including shape anisotropy [23,24], crystal facets [25], and entropy of the system [26,27]. In recent years, both in experiment and theory, researchers have been trying to identify the design parameters for the patches to direct assembly behaviors of patchy nanoparticles.…”

Morphologically Diverse Micro- and Macrostructures Created via Solvent Evaporation-Induced Assembly of Fluorescent Spherical Particles in the Presence of Polyethylene Glycol Derivatives

“…Their importance lies in the fact that artificially designed architectures with the desired morphologies and sizes may provide a variety of unexpected electronic, optical, sensing, and catalytic functions that differ from those of their small building blocks [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. To produce inorganic NP-based nano- and microstructures with desired dimensions [ 18 , 19 , 20 , 21 , 22 ], top-down and bottom-up strategies have been widely developed, for example, lithographic and patterning techniques [ 23 , 24 , 25 , 26 ], electrospinning [ 27 , 28 ], the Langmuir–Blodgett technique [ 29 , 30 ], solvent evaporation-driven self-assembly [ 31 , 32 , 33 ], and the polymer-mediated self-assembly of NP building blocks [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Most of the bottom-up polymer-mediated NP assembly strategies require the laborious introduction of specific functional groups on NP surfaces, the addition of certain salts, pH adjustment, etc.…”