Hierarchical Superstructures Assembled by Binary Hairy Nanoparticles

Abstract

Hierarchical superstructures assembled by binary mixed homopolymer-grafted nanoparticles are investigated by using a self-consistent field theory (SCFT). Our results demonstrate that grafting mixed homopolymer brushes provides an effective way to program the spatial lattice arrangement of the nanoparticles. For the polymer-grafted nanoparticles with specific interaction parameter and total grafting density, the unusual non-close-packed simple cubic (SC) crystal lattice is obtained at small spherical core/polymer size ratios (R/( N b) < 1). As the size ratio increases to R N b /() > 1, the nanoparticle arrangement transforms into a body-centered cubic (BCC) crystal lattice. Meanwhile, some unconventional microphases are formed in the polymer matrix, such as the tetragonal cylinder and simple cubic sphere phases. Furthermore, the two-dimensional (2D) model calculations reveal that the binary hairy nanoparticles prefer to arrange into the lattice in a way they can maintain the free energy-minimizing morphology as an isolated particle. Our findings suggest a possible strategy to design hierarchical nanomaterials composed of unique inorganic/organic hybrid superstructures.

Characterizing Polymer-Grafted Nanoparticles: From Basic Defining Parameters to Behavior in Solvents and Self-Assembled Structures

“…Multicomponent polymer brush-grafted NPs have received considerable interest in recent years, owing to their abilities to undergo chain reorganization within the brush layer in response to environmental changes, exhibiting distinct nanostructures under different conditions, and to self-assemble into hierarchical structures such as vesicles and tubules. ,− ,− ,− Examples of such HNPs include binary mixed polymer- and diblock copolymer-grafted NPs as well as bicomponent brush Janus NPs. The most important analytical tool for characterizing the self-assembled structures of multicomponent brush NPs is electron microscopy, including scanning electron microscopy (SEM), TEM, and TEM electron tomography (ET) .…”

“…For self-assembled nanostructures, even for one of the simplest multicomponent HNPs−binary mixed brushes on small NPs, the bulk morphologies have not been reported, although interesting nanostructures have been predicted by computer simulations. 102 It is our belief that ET will play a key role in elucidating the complex morphologies exhibited by multicomponent HNPs.…”

Two-Dimensional Plasmonic Nanoparticle as a Nanoscale Sensor to Probe Polymer Brush Formation

“…Despite the significant advancement of preparing polymer brushes for a wide range of applications, a fundamental understanding of the polymer brush formation mechanism has been stagnant over the past decades due to lack of appropriate analytical methods to investigate the brush formation in situ . − Since the first reports by Alexander and de Gennes, polymer brushes have been applied to a multitude of areas including surface patterning, − responsive materials design, − sensing, anticorrosion, antifouling, , polymer/nanoparticle self/directed-assembly, − stabilization, , lubrication, ,− compatibilization of polymer composites, − and modification of biological interfaces. − Polymer brushes are densely tethered polymer chains with one end attached to a surface. , To design polymer brushes effectively, it is crucial to understand the mechanism of polymer brush formation on surfaces. In the “ graft-to ” process, polymer chains first adsorb onto a surface and have a mushroom or pancake-like shape.…”

A comparative study of the self-assembly of achiral and chiral hairy nanoparticles with polystyrene cores and poly(2-hydroxyethylmethacrylate) hairs

“…The inorganic core-shell nanoparticles have been of interest because they can exhibit superior properties arising from the combination of characteristics and properties of the core particles and polymer components. 4,5 They possess unique chemical, physical, or biological properties due to their small size (10 nm to 100 nm), the increasing surface area to volume ratio and the presence of multiple functionalities on the shells, resulting in active materials for various areas of modern technology 6,7 such as resistant coatings, 8,9 pollution control, tire and rubber industry, 10 catalysis, 11 sensing, nanocarriers for drug and gene delivery. 12,13 Nanoparticles with their unique multifunctional and self-assembling properties have been widely used as valuable building blocks with great potential.…”