Sang Ouk Kim 교수

Crystal clear: The liquid crystallinity of graphene oxide platelets in aqueous dispersion is demonstrated. Graphene oxide sheets are arranged around liquid-crystal disclinations (see picture). The orientation of the liquid crystals can be manipulated by a magnetic field or mechanical deformation. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by th

Stable dispersion of reduced graphene in various organic solvents was achieved via noncovalent functionalization with amine-terminated polymers. An aqueous dispersion of reduced graphene was prepared by chemical reduction of graphene oxide in aqueous media and was vacuum filtered to generate reduced graphene sheets. Good solvents and nonsolvents for the dried reduced graphene were evaluated using a solubility test. To achieve stable dispersion in the evaluated nonsolvents, amine-terminated polys

Outstanding pristine properties of carbon nanotubes and graphene have limited the scope for real-life applications without precise controllability of the material structures and properties. This invited article to celebrate the 25th anniversary of Advanced Materials reviews the current research status in the chemical modification/doping of carbon nanotubes and graphene and their relevant applications with optimized structures and properties. A broad aspect of specific correlations between chemic

Site specific electroless gelation enables straightforward solution processing of graphene gel films with ultimate scalability and three-dimensional shape engineering. Due to the synergistic combination of open porous structure and highly electro-conductivity graphene gel framework, shape engineered gel films could be exploited for high performance supercapacitor electrode and achieved large energy capacity and high power density, simultaneously. As a service to our authors and readers, this jou

Two-dimensional (2D) MXene has shown enormous potential in scientific fields, including energy storage and electromagnetic interference (EMI) shielding. Unfortunately, MXene-based material structures generally suffer from mechanical fragility and vulnerability to oxidation. Herein, mussel-inspired dopamine successfully addresses those weaknesses by improving interflake interaction and ordering in MXene assembled films. Dopamine undergoes <i>in situ</i> polymerization and binding at MXene flake s

A hybrid system with vertical carbon nanotubes (CNTs) grown on reduced graphene films composed of overlapping and reduced graphene oxide platelets is reported. Such carbon hybrid films have excellent flexibility and stretchability (see image), can be readily transferred to any substrate including nonplanar surfaces, and were found to have Ohmic electrical contacts throughout all junctions in the CNT/metal-catalyst/graphene-film system. Detailed facts of importance to specialist readers are publi

Directed self-assembly of block copolymers has received a great deal of research attention as a promising nanolithography to complement the intrinsic limitations of conventional photolithography. In this review, we highlight the recent progress in the development of the directed self-assembly process for practical utilization in semiconductor applications. Various advanced directed self-assembly approaches are examined, in which block copolymer self-assembly is synergistically integrated with co

The discovery and relevant research progress in graphene oxide liquid crystals (GOLCs), the latest class of 2D nanomaterials exhibiting colloidal liquid crystallinity arising from the intrinsic disc-like shape anisotropy, is highlighted. GOLC has conferred a versatile platform for the development of novel properties and applications based on the facile controllability of molecular scale alignment. The first part of this review offers a brief introduction to LCs, including the theoretical backgro

Substitutional N‐doping of carbon nanomaterials refers to the chemical functionalization method that replaces a part of the carbon atoms in fullerene, carbon nanotubes, or graphene by nitrogen. N‐doping has attracted a tremendous amount of research attention for their unique possibilities, spanning from its ability to engineer various physiochemical properties of carbon nanomaterials in a stable manner with different dopant configurations. Many viable configurations of N‐dopants are accompanied

Bifunctional catalysts can facilitate two different electrochemical reactions with conflicting characteristics. Here, a highly reversible bifunctional electrocatalyst for rechargeable zinc-air batteries (ZABs) is reported featuring a "core-shell structure" in which N-doped graphene sheets wrap around vanadium molybdenum oxynitride nanoparticles. Single Mo atoms are released from the particle core during synthesis and anchored to electronegative N-dopant species in the graphitic shell. The result

We present a transparent and flexible optoelectronic material composed of vertically aligned ZnO NWs grown on reduced graphene/PDMS substrates. Large-area reduced graphene films were prepared on PDMS substrates by chemical exfoliation from natural graphitevia oxidative aqueous dispersion and subsequent thermal reduction. ZnO NWs were hydrothermally grown on the reduced graphene film substrate and maintained their structural uniformity even in highly deformed states. The electrical contact betwee

Artificial muscles are indispensable components for next-generation robotics capable of mimicking sophisticated movements of living systems. However, an optimal combination of actuation parameters, including strain, stress, energy density and high mechanical strength, is required for their practical applications. Here we report mammalian-skeletal-muscle-inspired single fibres and bundles with large and strong contractive actuation. The use of exfoliated graphene fillers within a uniaxial liquid

Novel Pt-Co alloyed nanocatalysts are generated via chemical vapor deposition-assisted facile one-pot synthesis. The method guarantees highly monodisperse Pt-Co alloy nanoparticles with precise control of metallic compositions within 1 at%. A significant features is that a perfectly alloyed single-crystal structure is obtained at temperatures as low as 500 °C, which is much lower than conventional alloying temperatures.

Rational design of 2D materials is crucial for the realization of their profound implications in energy and environmental fields. The past decade has witnessed significant developments in 2D material research, yet a number of critical challenges remain for real-world applications. Nanoscale assembly, precise control over the orientational and positional ordering, and complex interfaces among 2D layers are essential for the continued progress of 2D materials, especially for energy storage and con