A5022178744- Liquid Crystal Research Advancements
- Advanced Materials and Mechanics
- Supramolecular Self-Assembly in Materials
- Photochromic and Fluorescence Chemistry
- Polydiacetylene-based materials and applications
- Luminescence and Fluorescent Materials
- Synthesis and Properties of Aromatic Compounds
- Advanced Sensor and Energy Harvesting Materials
- Carbon Nanotubes in Composites
- Photonic Crystals and Applications
- Organic Electronics and Photovoltaics
- Molecular spectroscopy and chirality
- Fiber-reinforced polymer composites
- Silicone and Siloxane Chemistry
- Conducting polymers and applications
- Graphene research and applications
- Dendrimers and Hyperbranched Polymers
- Radiation Shielding Materials Analysis
- Polymer Nanocomposite Synthesis and Irradiation
- Organic and Molecular Conductors Research
- Surfactants and Colloidal Systems
- Polymer composites and self-healing
- Electrospun Nanofibers in Biomedical Applications
- Electrowetting and Microfluidic Technologies
- Lipid Membrane Structure and Behavior
Korea Institute of Science and Technology
2020-2025
Massachusetts Institute of Technology
2018-2021
Government of the Republic of Korea
2017-2021
Jeonbuk Development Institute
2021
Jeonbuk National University
2011-2020
Chonnam National University
2020
Chonbuk National University Hospital
2014-2018
Jeonju University
2014-2018
University of Ulsan
2013
Asan Medical Center
2013
Theoretical considerations suggest that the strength of carbon nanotube (CNT) fibers be exceptional; however, their mechanical performance values are much lower than theoretical values. To achieve macroscopic with ultrahigh performance, we developed a method to form multidimensional nanostructures by coalescence individual nanotubes. The highly aligned wet-spun single- or double-walled bundles were graphitized induce collapse and multi-inner walled structures. These advanced formed network...
Many strategies for manufacturing high-performance carbon nanotube (CNT) fibers have been reported in the past decade. Although spinning is an essential process regardless of CNT pre-treatment method or fiber post-treatment route, little research has carried out into itself. During formation such through spinning, intra- and inter-bundle voids inevitably arise. The size amount these determines macroscopic properties fibers. Therefore, controlling internal key enhancing their properties. We...
A promising way to induce shape transformation in soft materials is via spatial variation the orientation of alignment liquid crystalline elastomers (LCEs). Here, we improve nascent thermomechanial main-chain LCEs prepared aza-Michael addition reactions. Specifically, increasing alkyl length n-alkylamine chain extender effectively reduces actuation temperature by destabilizing nematic phase as well glass transition (Tg) free volume. In addition, incorporating a hydroxyl end-group amine...
For liquid crystal (LC) alignment, polyhedral oligomeric silsesquioxanes (POSS) can be considered as one of the promising candidates for formation vertical alignment (VA) LC. However, because their poor compatibility and weak interaction with LC hosts, pristine POSS are highly aggregate themselves in media create macroscopic particles, resulting severe light scatterings. To overcome this barrier, we proposed successfully synthesized cyanobiphenyl monosubstituted giant molecule (abbreviated...
Utilizing sequential layer-by-layer (LBL) coating and subsequent photopolymerization, we developed circular-polarizing free-standing mirrors with a broad reflection bandwidth. Photopolymerizable cholesteric liquid crystal (CLC) paints were first prepared by considering the intrinsic chirality viscoelasticity. The polymer-stabilized nanostructures had finely tuned helical pitches that selectively reflected light over entire visible wavelength range. CLC films exhibited excellent...
By considering intramolecular conformations and intermolecular interactions, an azobenzene-based photochromic liquid crystalline amphiphile is synthesized for demonstrating a remote-controllable light shutter by the photo-induced isothermal phase transition between highly ordered crystal isotropic phase.
For the demonstration of remote‐controllable actuators, a dendronized polymer (denpol) is newly designed and successfully synthesized by ring‐opening metathesis polymerization azobenzene‐based macromonomers. The incorporation azobenzene mesogens into denpols helps to construct finely tuned hierarchical superstructures with anisotropic physical properties reversible photoisomerization. polynorbornene backbones side chains in uniaxially oriented films are aligned perpendicularly parallel layer...
Abstract Individual carbon nanotubes (CNT) and graphene have unique mechanical electrical properties; however, the properties of their macroscopic assemblies not met expectations because limited physical dimensions, degree dispersion components, various structural defects. Here, a state‐of‐the‐art assembly for novel type hybrid fiber possessing required wide variety multifunctional applications is presented. A simple effective multidimensional nanostructure CNT oxide (GO) assembled by...
Abstract A ribbon‐shaped chiral liquid crystalline (LC) dendrimer with photochromic azobenzene mesogens and an isosorbide center (abbreviated as AZ 3 DLC) was successfully synthesized its major phase transitions were studied by using differential scanning calorimetry (DSC) linear polarized optical microscopy (POM). Its ordered structures at different temperatures further identified through structure‐sensitive diffraction techniques. Based on the experimental results, it found that DLC...
The preparation of materials exhibiting structural colors has been intensively studied in biomimetic science and technology. Utilizing a newly synthesized cholesteric liquid-crystal (CLC) monomer (abbreviated as BP1CRM), we have prepared CLC films. Photoinitiated copolymerization this with common achiral liquid-crystalline produced free-standing films homogeneous nanoscale pitch distributions. Employing the thermal sensitivity monomer, chirophotonic crystal reflectors were range colors....
Abstract Solid‐state luminescence is an important strategy for color generation via molecular self‐assembly. Here, a new luminogen (AT 3 EMIS) containing both rigid chromophore and flexible dendron designed synthesized multicolor emission. The emission energy of the target material precisely controlled by adjusting three different columnar arrays through thermal mechanical stimulation. With well‐defined supramolecular organizations in length scales, luminescent properties light switch can be tuned.
The well-defined hierarchical superstructures constructed by the self-assembly of programmed supramolecules can be organized for fabrication remote-controllable actuating and rewritable films. To realize this concept, we newly designed synthesized a benzene-1,3,5-tricarboxamide (BTA) derivative (abbreviated as BTA-3AZO) containing photoresponsive azobenzene (AZO) mesogens on periphery BTA core. BTA-3AZO was first self-assembled to nanocolumns mainly driven intermolecular hydrogen-bonds...
Light manipulation strategies of nature have fascinated humans for centuries. In particular, structural colors are considerable interest due to their ability control the interaction between light and matter. Here, wrinkled photonic crystal papers (PCPs) fabricated demonstrate consistent reflection regardless viewing angles. The nanoscale molecular self-assembly a cholesteric liquid (CLC) with microscale corrugated surface is combined. Fully polymerizable CLC paints uniaxially coated onto...
Individual carbon nanotubes (CNTs) have gained popularity as lightweight wire materials due to their high electrical conductivity and low density than that of copper wires. Despite intensive research on light-weight highly conductive CNT fibers, the bulk properties assemblies are inferior those metal wires in terms conductivity. Herein, we propose a method increase specific fibers with polyaniline (PANI). The structure physical precisely controlled by optimizing PANI content through simple...
Abstract By varying counter ions of ion‐conductive mesogens (ICMs) from bromide (Br), to tetrafluoroborate (BF 4 ), and bis(trifluoromethanesulfonyl)imide (TFSI), the ionic conductivity ICM is systematically investigated based on their self‐assembled nanostructure activation energy. Thermal phase transition behaviors ICM‐Br, ‐BF , ‐TFSI exhibit significant variation anion type. These differences are further reflected in nanostructures ICMs, which characterized through X‐ray electron...
Abstract The development of high-performance fibers using carbon nanotubes (CNTs) has gained significant attention due to their extraordinary mechanical, electrical, and thermal properties. In this study, we focus on the selective sorting wet spinning high aspect ratio CNTs enhance physical properties resulting fibers. By utilizing a lyotropic liquid crystal (LLC) mesophase, effectively separated long short CNTs. At isotropic cloud point (ICP), form nematic domains while remain in phase,...
Photoresponsive carbohydrate-based giant surfactants (abbreviated as CELAnD-OH) were specifically designed and synthesized for the automatic vertical alignment (VA) layer of nematic (N) liquid crystal (LC), which can be applied fabrication remote-controllable optical devices. Without conventional polymer-based LC process, a perfect VA was automatically constructed by directly adding 0.1 wt % CELA1D-OH in N-LC media. The programmed media gradually diffused onto substrates cell self-assembled...
A programed light‐responsive chiral liquid crystal (LC) containing four photochromic azobenzene moieties covalently connected to a central bicyclic core (abbreviated as AZ 4 ICD) is newly designed, precisely synthesized, and efficiently applied remote‐controllable molecular knob for the optically tunable thin film. First of all, phase evolutions ordered structures ICD are systematically investigated by combination thermal, microscopic, scattering, simulation techniques. Wide‐angle X‐ray...