Fe-N@Graphene Single-Atom Catalyst-Based Nanozyme against Influenza A Virus.

Recent COVID-19 pandemic has raised an urgent need for effective strategies to combat viruses that can pose serious health threats to the entire human race. Incorporating antipathogenic functions into everyday objects and personal protective equipment has become increasingly important, motivating the development of general-purpose antiviral materials. Single-atom catalysts, known for superior catalytic performance and maximized atomic utilization, have been explored in various research fields, including artificial nanozymes for bioapplications.

Bioinspired Deformable Antireflective Materials by Block Copolymer Self-Assembly.

Antireflective surface is a crucial component for high-performance photonic systems but has been principally focused on hard, flat device geometry. We present an antireflective strategy for deformable device geometry that combines superior optical performance with mechanical robustness. Bioinspired nanohole arrays are embedded into a transparent polymer layer by exploiting block copolymer self-assembly.

Surface Energy Tailored Reduced Graphene Oxide Top-Coat for Vertical Alignment of High-χ Block Copolymers for Sub-10-nm Nanopatterning.

Vertically aligned nanopatterns of high Flory-Huggins parameter (χ) block copolymers (BCPs) are desirable for effective pattern transfer of sub-10-nm scale self-assembled morphologies. To this end, BCP thin film is required to interface with neutralized surface energy at both substrate and free-surface, among which neutralization of top free-surface is generally more difficult without well-defined substrate geometry. Therefore, various types of top-coat layers have been developed, many of which, however, require complex synthetic processes or specifically designed equipment.

Monodisperse Pt nanoparticle arrays block copolymer nanopatterning and their reaction kinetics on CO oxidation.

Advances in nanotechnology are able to open up new prospects for catalysis, particularly through the development of catalytic systems featuring precisely controlled size and distribution of metal nanoparticles. In this study, we prepared a model catalytic system, where monodisperse Pt nanoparticles, approximately 8 nm in size, were uniformly distributed onto CeO and SiO/Si substrates block copolymer (BCP) nanopatterning. To address the validity of these catalysts, we conducted a case study on CO oxidation in a continuous flow reactor, investigated the reaction kinetics, and compared our observations with those reported in the literature.

Sunlight-Driven Self-Cleaning Ultrafine Particulate Matter Filter with Antibacterial Activity.

Air pollution by particulate matter (PM) and airborne pathogens causes severe health problems in the human body. Presently, popular disposable air filters yield huge waste and have a fatal impact on the environment. Postuse cleaning of air filters also leads to secondary air and water pollution.

Polymer-Based Thermally Stable Chemiresistive Sensor for Real-Time Monitoring of NO Gas Emission.

We present a thermally stable, mechanically compliant, and sensitive polymer-based NO gas sensor design. Interconnected nanoscale morphology driven from spinodal decomposition between conjugated polymers tethered with polar side chains and thermally stable matrix polymers offers judicious design of NO-sensitive and thermally tolerant thin films. The resulting chemiresitive sensors exhibit stable NO sensing even at 170 °C over 6 h.

Molecularly Hybridized Conduction in DPP-Based Donor-Acceptor Copolymers toward High-Performance Iono-Electronics.

Iono-electronics, that is, transducing devices able to translate ionic injection into electrical output, continue to demand a variety of mixed ionic-electronic conductors (MIECs). Though polar sidechains are widely used in designing novel polymer MIECs, it remains unclear to chemists how much balance is needed between the two antagonistic modes of transport (ion permeability and electronic charge transport) to yield high-performance materials. Here, the impact of molecularly hybridizing ion permeability and charge mobility in semiconducting polymers on their performance in electrochemical and synaptic transistors is investigated.

Multilevel Self-Assembly of Block Copolymers and Polymer Colloids for a Transparent and Sensitive Gas Sensor Platform.

The recent emerging significance of the Internet of Things (IoT) demands sensor devices to be integrated with many different functional structures and devices while conserving their original functionalities. To this end, optical transparency and mechanical flexibility of sensor devices are critical requirements for optimal integration as well as high sensitivity. In this work, a transparent, flexible, and sensitive gas sensor building platform is introduced by using multilevel self-assembly of block copolymers (BCPs) and polystyrene (PS) colloids.

Atomically Flat, 2D Edge-Directed Self-Assembly of Block Copolymers.

Nanoscale shape engineering is an essential requirement for the practical use of 2D materials, aiming at precisely customizing optimal structures and properties. In this work, sub-10-nm-scale block copolymer (BCP) self-assembled nanopatterns finely aligned along the atomic edge of 2D flakes, including graphene, MoS , and h-BN, are exploited for reliable nanopatterning of 2D materials. The underlying mechanism for the alignment of the self-assembled nanodomains is elucidated based on the wetting layer alternation of the BCP film in the presence of intermediate 2D flakes.

A 2D Ultrathin Nanopatterned Interlayer to Suppress Lithium Dendrite Growth in High-Energy Lithium-Metal Anodes.

A novel strategy for robust and ultrathin (<1 µm) multilayered protective structures to address uncontrolled Lithium (Li) dendrite growth at Li-metal battery anodes is reported. Synergetic interaction among Ag nanoparticles (Ag NPs), reduced graphene oxide (rGO) films, and self-assembled block-copolymer (BCP) layers enables effective suppression of dendritic Li growth. While Ag NP layer confines the growth of Li metal underneath the rGO layer, BCP layer facilitates the fast and uniformly distributed flux of Li-ion transport and mechanically supports the rGO layer.

Wide-Range Size Fractionation of Graphene Oxide by Flow Field-Flow Fractionation.

Many interesting properties of 2D materials and their assembled structures are strongly dependent on the lateral size and size distribution of 2D materials. Accordingly, effective size separation of polydisperse 2D sheets is critical for desirable applications. Here, we introduce flow field-flow fractionation (FlFFF) for a wide-range size fractionation of graphene oxide (GO) up to 100 μm.

Molecular-Level Lubrication Effect of 0D Nanodiamonds for Highly Bendable Graphene Liquid Crystalline Fibers.

Graphene fiber is emerging as a new class of carbon-based fiber with distinctive material properties particularly useful for electroconductive components for wearable devices. Presently, stretchable and bendable graphene fibers are principally employing soft dielectric additives, such as polymers, which can significantly deteriorate the genuine electrical properties of pristine graphene-based structures. We report molecular-level lubricating nanodiamonds as an effective physical property modifier to improve the mechanical flexibility of graphene fibers by relieving the tight interlayer stacking among graphene sheets.

Block Copolymer Nanopatterning for Nonsemiconductor Device Applications.

Block copolymer (BCP) nanopatterning has emerged as a versatile nanoscale fabrication tool for semiconductor devices and other applications, because of its ability to organize well-defined, periodic nanostructures with a critical dimension of 5-100 nm. While the most promising application field of BCP nanopatterning has been semiconductor devices, the versatility of BCPs has also led to enormous interest from a broad spectrum of other application areas. In particular, the intrinsically low cost and straightforward processing of BCP nanopatterning have been widely recognized for their large-area parallel formation of dense nanoscale features, which clearly contrasts that of sophisticated processing steps of the typical photolithographic process, including EUV lithography.

Wafer-Scale Unidirectional Alignment of Supramolecular Columns on Faceted Surfaces.

The long-range alignment of supramolecular structures must be engineered as a first step toward advanced nanopatterning processes aimed at miniaturizing features to dimensions below 5 nm. This study introduces a facile method of directing the orientation of supramolecular columns over wafer-scale areas using faceted surfaces. Supramolecular columns with features on the sub-5 nm scale were highly aligned in a direction orthogonal to that of the facet patterning on unidirectional and nanoscopic faceted surface patterns.

Multidimensional TiCT MXene Architectures Interfacial Electrochemical Self-Assembly.

An effective pathway to build macroscopic scale functional architectures bearing diverse structural dimensions is one of the critical challenges in the two-dimensional (2D) MXene research area. Unfortunately, assembling MXene without adhesive binder is largely limited due to its innate brittle nature and the relatively weak inter-flake van der Waals contact, in contrast to other mechanically compliant 2D materials such as graphene. Herein, an electrochemical self-assembly of pure TiCT MXenes is presented for functional multidimensional MXene structures, effectively driven by layer-by-layer spontaneous interfacial reduction at metal template surfaces and subsequent defunctionalization.

Highly Aligned Carbon Nanowire Array by E-Field Directed Assembly of PAN-Containing Block Copolymers.

Nanoscale engineering of carbon materials is immensely demanded in various scientific areas. We present highly ordered nitrogen-doped carbon nanowire arrays block copolymer (BCP) self-assembly under an electric field. Large dielectric constant difference between distinct polymer blocks offers rapid alignment of PMMA--PAN self-assembled nanodomains under an electric field.

Conformal 3D Nanopatterning by Block Copolymer Lithography with Vapor-Phase Deposited Neutral Adlayer.

Block copolymer (BCP) lithography is an effective nanopatterning methodology exploiting nanoscale self-assembled periodic patterns in BCP thin films. This approach has a critical limitation for nonplanar substrate geometry arising from the reflow and modification of BCP films upon the thermal or solvent annealing process, which is inevitable to induce the mobility of BCP chains for the self-assembly process. Herein, reflow-free, 3D BCP nanopatterning is demonstrated by introducing a conformally grown adlayer by the initiated chemical vapor deposition (iCVD) process.

Nanopatterns with a Square Symmetry from an Orthogonal Lamellar Assembly of Block Copolymers.

A nanosquare array is an indispensable element for the integrated circuit design of electronic devices. Block copolymer (BCP) lithography, a promising bottom-up approach for sub-10 nm patterning, has revealed a generic difficulty in the production of square symmetry because of the thermodynamically favored hexagonal packing of self-assembled sphere or cylinder arrays in thin-film geometry. Here, we demonstrate a simple route to square arrays via the orthogonal self-assembly of two lamellar layers on topographically patterned substrates.

Ultralarge Area Sub-10 nm Plasmonic Nanogap Array by Block Copolymer Self-Assembly for Reliable High-Sensitivity SERS.

Effective surface enhancement of Raman scattering (SERS) requires strong near-field enhancement as well as effective light collection of plasmonic structures. To this end, plasmonic nanoparticle (NP) arrays with narrow gaps or sharp tips have been suggested as desirable structures. We present a highly dense and uniform Au nanoscale gap array enabled by the customized design of NP shape and arrangement employing block copolymer self-assembly.

Bimodal phase separated block copolymer/homopolymer blends self-assembly for hierarchical porous metal nanomesh electrodes.

Transparent conducting electrodes (TCEs) are essential components in various optoelectronic devices. Nanostructured metallic thin film is one of the promising candidates to complement current metal oxide films, such as ITO, where high cost rare earth elements have been a longstanding issue. Herein, we present that multiscale porous metal nanomesh thin films prepared by bimodal self-assembly of block copolymer (BCP)/homopolymer blends may offer a new opportunity for TCE.