Jeong Gon Son

Sub-10 nm Graphene Nanoribbon Arrays are fabricated over large areas by etching CVD-grown graphene. A mask is used made by the directed self-assembly of a cylindrical PS-b-PDMS block copolymer under solvent annealing guided by a removable template. The optimized solvent annealing process, surface-modified removable polymeric templates, and high Flory-Huggins interaction parameters of the block copolymer enable a highly aligned array of nanoribbons with low line edge roughness to be formed. This

A perpendicular orientation of high-aspect-ratio polystyrene-<i>block</i>-polydimethylsiloxane (PS-<i>b</i>-PDMS) cylindrical and lamellar PDMS microdomains was achieved by solvent annealing and then slowly drying thick PS-<i>b</i>-PDMS films. Perpendicularly oriented microdomains occurred throughout the film thickness, except at the air interface, where a layer of in-plane microdomains formed due to the surface energy difference between PS and PDMS. In contrast, thermal annealing produced in-pl

Block copolymer self-assembly generates patterns with periodicity in the ∼10-100 nm range and is increasingly recognized as a route to lithographic patterning beyond the resolution of photolithography. Block copolymers naturally produce periodic patterns with a morphology and length-scale determined by the molecular architecture, and considerable research has been carried out to extend the range of patterns that can be produced from a given block copolymer, but the ability to control the period

Poly(styrene-block-dimethylsiloxane) (PS-b-PDMS) block copolymers with a period as low as 13 nm have been self-assembled on a template formed from PS-b-PDMS of a 34–40 nm period, which is itself templated by micron-scale substrate features prepared using conventional lithography. This hierarchical process provides a simple method for directing the self-assembly of sub-10 nm features and registering them on the substrate.

Stretchable energy storage devices are of great interest because of their potential applications in body-friendly, skin-like, wearable devices. However, stretchable batteries are very challenging to fabricate. The electrodes must have a degree of stretchability because the active materials occupy most of the volume, and the separator and packaging should also be stretchable. Here, an all-component stretchable lithium-ion battery was realized by leveraging the structural stretchability of re-entr

We present a control strategy for the facile placement of densely packed nanomaterial arrays (i.e., nanoparticles and nanorods) on surface reconstructed polystyrene-block-poly(methyl methacrylate) thin film patterns. The surface reconstruction of perpendicularly oriented block copolymer thin films, which were produced by a treatment with selective solvent vapors for both blocks, created the topographical nanopatterns with enough height contrast for nanoparticle deposition without the need for ad

Stretchable energy storage systems are essential for the realization of implantable and epidermal electronics. However, high-performance stretchable supercapacitors have received less attention because currently available processing techniques and material structures are too limited to overcome the trade-off relationship among electrical conductivity, ion-accessible surface area, and stretchability of electrodes. Herein, we introduce novel 2D reentrant cellular structures of porous graphene/CNT

From graphene oxide wrapped iron oxide particles with etching/reduction process, high-performance anode and cathode materials of lithium-ion hybrid supercapacitors are obtained in the same process with different etching conditions, which consist of partially etched crumpled graphene (CG) wrapped spiky iron oxide particles (CG@SF) for a battery-type anode, and fully etched CG for a capacitive-type cathode. The CG is formed along the shape of spikily etched particles, resulting in high specific su

Achieving sub‐10 nm high‐aspect‐ratio patterns from diblock copolymer self‐assembly requires both a high interaction parameter ( χ , which is determined by the incompatibility between the two blocks) and a perpendicular orientation of microdomains. However, these two conditions are extremely difficult to achieve simultaneously because the blocks in a high‐ χ copolymer typically have very different surface energies, favoring in‐plane microdomain orientations. A fully perpendicular orientation of

Square-symmetry patterns are of interest in nanolithography but are not easily obtained from self-assembly of a diblock copolymer. Instead, we demonstrate highly ordered 44 nm period square patterns formed in a thin film of polyisoprene-block-polystyrene-block-polyferrocenylsilane (PI-b-PS-b-PFS) triblock terpolymer blended with 15% PS homopolymer by controlling the film thickness, solvent anneal conditions, the surface chemistry and topography of the substrates. The square patterns consist of P

The addition of surfactants, which preferentially interact with the PMMA block domains, modifies the surface energy of the system by making the surface energy difference between the two blocks almost equal, resulting in the perpendicular orientation of microphase separated domains in the film. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2089/2008/adma200800670_s.pdf or from the author. Please note: The publisher is not responsible for

A crumpled configuration of graphene is desirable for preventing irreversible stacking between individual nanosheets, which can be a major hurdle toward its widespread application. Herein a sea‐urchin‐shaped template approach is introduced for fabricating highly crumpled graphene balls in bulk quantities with a simple process. Simultaneous chemical etching and reduction process of graphene oxide (GO)‐encapsulated iron oxide particles results in dissolution of the core template with spiky morphol

Sub-10 nm patterns prepared by directed self-assembly (DSA) of block copolymer (BCP) thin films offer a breakthrough method to overcome the limitations of photolithography. Perpendicular orientation of the BCP nanostructures is essential for lithographic applications, but dissimilar surface/interfacial energies of two blocks generally favour parallel orientations, so that the perpendicular orientation could only be obtained under very limited conditions. Here, we introduce a generalized method f