Phase separation in mixed polymer brushes on nanoparticle surfaces enables the generation of anisotropic nanoarchitectures

Abstract

The preparation of nanoparticles and their targeted connection with other functional units is one key challenge in developing nanoscale devices. Herein, we report an experimental strategy toward the development of anisotropic nanoparticle architectures. Our approach is based on phase separation of binary mixed polymer brushes on gold nanoparticle surfaces leading to Janus-type structures, as revealed by scanning transmission electron microscopy and electron energy-loss spectroscopy and, additionally, corroborated by computer simulation. We show that such structures can be used for the site-selective functionalization with additional nanosized entities.

Mechanical cleaning of graphene using in situ electron microscopy

“…3g, inset). While the former value fits well to the plasmon signature of PMMA 25 , the latter is more indicative of pristine monolayer graphene 26 . Even though the cleaned sample was exposed to ambient conditions and is therefore repopulated with contamination originating from air, the carbon K-edge fine structure is much better resolved due to the reduced thickness of the contamination layer.…”

Helicoidal Patterning of Nanorods with Polymer Ligands

“…[11,19,20] Notably, chiral packing of ligands on the NP surface can occur with achiral molecules, as shown for achiral thiolates attached to the surface of gold clusters. [2] Alternatively, an asymmetric ligand shell formed due to a microphase separation on the NP surface [21,22] can also lead to induced chirality. [1] Recently, we have proposed a new approach to the surface patterning of spherical NPs tethered with end-grafted polymer molecules.…”

Nanostructuring Single-Molecule Polymeric Nanoparticles via Macromolecular Architecture

“…To this end, grafting chemically distinct polymer chains to the surface of a solid or an organic nanoparticle, thus forming mixed brushgrafted nanoparticles, has attracted considerable attention as a practical route to construct multicompartment nanostructured particles. 8,9,22 In this case, when two immiscible polymers are grafted onto the nanoparticle, they can phase separate into different domains at the nanoparticle surface due to the balance between maximizing chain entropy and minimizing unfavorable contacts between the immiscible polymer chains. Depending on the polymer chain lengths, the Flory interaction strength, the grafting density, and the size of the solid particle, the self-consistent mean field theory and the fluctuating dynamic mean field theory have predicted the creation of a variety of surface patterns from Janus to multi-patchy ones.…”

“…Among the diverse family of polymer nanoparticles, nanostructured ones, composed of two or more chemically distinct components, have attracted considerable attention because they can be employed as the building blocks for the synthesis of multiphase nanostructured materials. To this end, grafting chemically distinct polymer chains to the surface of a solid or an organic nanoparticle, thus forming mixed brush-grafted nanoparticles, has attracted considerable attention as a practical route to construct multicompartment nanostructured particles. ,, In this case, when two immiscible polymers are grafted onto the nanoparticle, they can phase separate into different domains at the nanoparticle surface due to the balance between maximizing chain entropy and minimizing unfavorable contacts between the immiscible polymer chains. Depending on the polymer chain lengths, the Flory interaction strength, the grafting density, and the size of the solid particle, the self-consistent mean field theory and the fluctuating dynamic mean field theory have predicted the creation of a variety of surface patterns from Janus to multi-patchy ones. − Such surface morphologies may be used as a direct way to empower specific interactions between nanoparticles and, consequently, direct their self-assembly behavior as well as the mesoscopic morphology of the resulting material.…”