Jinseok Lee

Zeolites are crystalline nanoporous aluminosilicates widely used in industry. In order for zeolites to find applications as innovative materials, they need to be organized into large two- and three-dimensional (2D and 3D) arrays. We report that uniformly aligned polyurethane films can serve as templates for the synthesis of uniformly aligned 2D and possibly 3D arrays of silicalite-1 crystals, in which the orientations of the crystals are controlled by the nature of the polymers. We propose that

Atoms, molecules, enzymes, proteins, DNAs, RNAs, nanoparticles, microparticles, tiles, and bricks are some of the most commonly encountered building blocks in chemistry and architecture. These building blocks can be grouped into subnanometer (atoms), nanometer (molecules, enzymes, proteins, DNAs, RNAs, and nanoparticles), micrometer (microparticles), and millimeter-to-centimeter (tiles and bricks) building blocks based on their sizes. One of the important applications of building blocks is to or

Which way to turn: The tendency of microcrystals to attach to surfaces through their largest faces has resulted in two orientations of zeolite L monolayers on glass. Fluorophore-containing cylindrical and hexagonal columnar zeolite L crystals assemble into vertically and horizontally oriented monolayers, respectively, on glass plates (see pictures). The photoluminescences of the monolayers are highly anisotropic.

Investigation of molecular interactions in polymeric films is crucial for understanding and engineering multiscale physical phenomena correlated to device function and performance, but this often involves a compromise between theoretical and experimental data, because of poor film uniformity. Here, we report the intramolecular and intermolecular interactions inside the ultrathin and conformal hybrid organic-inorganic alucone films grown by molecular layer deposition, based on sequential and self

Graphene domains with different sizes and densities were successfully grown on Cu foils with use of a chemical vapor deposition method. We investigated the effects of volume ratios of argon to hydrogen during the annealing process on graphene growth, especially as a function of hydrogen partial pressure. The mean size and density of graphene domains increased with an increase in hydrogen partial pressure during the annealing time. In addition, we found that annealing with use of only hydrogen ga

In this work, we report that high-density, vertically grown silicon nanowires (vg-SiNWs) direct a new in vitro developmental pathway of primary hippocampal neurons. Neurons on vg-SiNWs formed a single, extremely elongated major neurite earlier than minor neurites, which led to accelerated polarization. Additionally, the development of lamellipodia, which generally occurs on 2D culture coverslips, was absent on vg-SiNWs. The results indicate that surface topography is an important factor that inf

Development of methods enabling the preparation of uniformly aligned polymer thin films at the molecular level is a prerequisite for realizing their optoelectronic characteristics as innovative materials; however, these methods often involve a compromise between scalability and accuracy. In this study, we have grown uniformly aligned polyurea thin films on a SiO2 substrate using molecular layer deposition (MLD) based on sequential and self-limiting surface reactions. By integrating plane-polariz

Do-it-yourself: Monoschichten von Molekülen und Nanopartikeln sollten auf den Substraten nur durch Selbstorganisation erzeugt werden. Für Monoschichten von Mikropartikeln kommt als Alternative das direkte Aufbringen von Hand hinzu, bei dem sich die Partikel wie Fliesen einpassen (siehe Bild). Die Qualität der händisch erzeugten Monoschichten übertrifft diejenige der Produkte aus Selbstorganisationsverfahren. Supporting information for this article is available on the WWW under http://www.wiley-v

Cellular adhesion and growth on substrates with differing surface topography are known to induce unusual cell behaviors. Here, we investigated the adhesion and growth of human embryonic kidney 293T cells on vertically aligned silicon nanowires. Varying the diameter of nanowires affected their elasticity, which in turn caused variations in cell morphology and adhesion. Calculation of their elastic modulus revealed that long and thin nanowires are easier to deflect and thus provide more focal adhe

Here, we investigated the translocation of biomolecules, such as DNA and protein, through a sequentially polymerized polyurea nanopore, with a thin (<10 nm) polymer membrane of uniform thickness. The polyurea membrane was synthesized by molecular layer deposition using p-phenylenediisocyanate (PDI) and p-phenylenediamine (PDA) as sequential precursors. The membrane exhibited a hydrophobic surface with a highly negative surface charge density (-51 mC m-2 at pH 8). It was particularly noted that t

Anisotropic graphene domains are of significant interest since the electronic properties of pristine graphene strongly depend on its size, shape, and edge structures. In this work, considering that the growth of graphene domains is governable by the dynamics of the graphene-substrate interface during growth, we investigated the shape and defects of graphene domains grown on copper lattices with different indices by chemical vapor deposition of methane at either low pressure or atmospheric pressu