A5090401100- Block Copolymer Self-Assembly
- Advanced Polymer Synthesis and Characterization
- Polymer Surface Interaction Studies
- Cancer, Hypoxia, and Metabolism
- Conducting polymers and applications
- Advanced Sensor and Energy Harvesting Materials
- Epigenetics and DNA Methylation
- Polymer crystallization and properties
- Organic Electronics and Photovoltaics
- Rheology and Fluid Dynamics Studies
- Surfactants and Colloidal Systems
- Fluid Dynamics and Thin Films
- Carbon Nanotubes in Composites
- Material Dynamics and Properties
- Machine Learning in Materials Science
- Nanopore and Nanochannel Transport Studies
- Crystallization and Solubility Studies
- Nanofabrication and Lithography Techniques
- biodegradable polymer synthesis and properties
- Polymer Nanocomposites and Properties
- Liquid Crystal Research Advancements
- Cancer Research and Treatments
- Theoretical and Computational Physics
- Advanced Materials and Mechanics
- RNA modifications and cancer
Korea University
2015-2024
Government of the Republic of Korea
2017-2019
Seoul Institute
2017-2018
Yonsei University
1996-2013
Seoul National University
1992-2010
Pohang University of Science and Technology
2008-2009
Pohang Accelerator Laboratory
2009
University of Massachusetts Amherst
2008
Kumoh National Institute of Technology
2007
Dankook University
2006
We investigate the influence of hard nanoparticles on phase behavior diblock copolymers. Using Monte Carlo simulations, we obtain diagrams as a function nanoparticle size and concentration. When becomes comparable to radius gyration minority (A) block, observe formation new superstructures, where particles self-assemble inside copolymer micelles. develop theoretical model, based strong segregation limit approximation, show that these self-assembled structures can be either stable or...
The crystalline structures associated with melting and crystallization behaviors of monodisperse linear polyethylene confined in cylindrical nanopores were investigated by X-ray diffraction differential scanning calorimetry. structures, melting, PE under the imposed confinement noticeably different from those bulk state. isothermal experiments showed that overall was dominated nucleation rather than growth crystallites. c- a-axes orthorhombic crystals developed nanoporous alumina...
The crystallization of monodisperse linear polyethylene confined in nanoporous alumina is investigated with the calorimetric measurements. We observe a drastic change behavior, specifically nucleation, decrease pore diameter. Crystallization relatively larger pores diameters 62 and 110 nm occurs at lower temperatures within very narrow range, whereas smaller 15-48 higher broad range temperatures. Nucleation kinetics nanopores discussed based on classical nucleation theory as well Avrami theory.
Self-assembled structures of brush block copolymers (BrBCPs) with polylactide (PLA) and polystyrene (PS) side chains were studied. The polynorbornene-backbone-based BrBCPs containing approximately equal volume fractions each self-assembled into highly ordered lamellae domain spacing ranging from 20 to 240 nm by varying molecular weight the backbone in bulk state, as revealed small-angle X-ray scattering (SAXS). size increased linearly length, which indicated an extended conformation state....
We demonstrate significantly improved performance of a nonvolatile polymeric ferroelectric field effect transistor (FeFET) memory using nanoscopic confinement poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) within self-assembled organosilicate (OS) lamellae. Periodic OS lamellae with 30 nm in width and 50 periodicity were templated block copolymer self-assembly. Confined crystallization PVDF-TrFE not only reduces gate leakage current but also facilitates polarization switching....
The directed assembly of block copolymer nanostructures with large periods exceeding 100 nm remains challenging because the translational ordering long-chained is hindered by its very low chain mobility. Using a solvent-vapor annealing process neutral solvent, which was sequentially combined thermal process, we demonstrate rapid evolution perpendicularly oriented lamellar morphology in high molecular weight films on substrate. synergy topographically patterned substrate facilitated...
Structural colors (SCs) of photonic crystals (PCs) arise from selective constructive interference incident light. Here, an ink-jet printable and rewritable block copolymer (BCP) SC display is demonstrated, which can be quickly written erased over 50 times with resolution nearly equivalent to that obtained a commercial office printer. Moreover, the writing process employs easily modified printer for position- concentration-controlled deposition single, colorless, water-based ink containing...
The development of electrically responsive sensors based on the capacitance, voltage, and resistance that can detect simultaneou sly visualize large strain involved with human motion is in great demand. Here, we demonstrate a highly stretchable, capacitive sensor strain-responsive structural color (SC). Our device contains an elastomeric sensing film produces capacitance change under strain, which self-assembled block copolymer (BCP) photonic crystal (PC) 1D periodic in-plane lamellae...
The development of a lightweight, low-power, user-interactive three-dimensional (3D) touchless display in which human stimulus can be detected and simultaneously visualized noncontact mode is great interest. Here, we present 3D sensing based on multiorder reflection structural colors (SCs) thin, solid-state block copolymer (BCP) photonic crystal (PC). Full-visible-range SCs are developed BCP PC consisting alternating lamellae, one contains chemically cross-linked, interpenetrated hydrogel...
For the development of wearable electronics, replacement rigid, metallic components with fully elastomeric materials is crucial. However, current electrodes suffer from low electrical conductivity and poor stability. Herein, a metal-like conductive elastomer exceptional performance stability presented, which used to fabricate electronics. The key feature this material its wrinkled structure, induced by in situ cooperation solvent swelling densely packed nanoparticle assembly. Specifically,...
Hydrogels have diverse chemical properties and can exhibit reversibly large mechanical deformations in response to external stimuli; these characteristics suggest that hydrogels are promising materials for soft robots. However, reported actuators based on generally suffer from slow speed and/or poor controllability due intrinsic material limitations electrode fabrication technologies. Here, we report a hydrogel actuator operates at low voltages (<3 volts) with high performance (strain...
We introduce silk textile-based water-splitting electrodes that can significantly increase the electrocatalytic performance for both HER and OER by a carbonization/interfacial assembly-driven electroplating approach.
Palmitic acid (PA) is the most common fatty in humans and mediates palmitoylation through its conversion into palmitoyl coenzyme A. Although affects many proteins, pathophysiological functions are only partially understood. Here we demonstrate that PA acts as a molecular checkpoint of lipid reprogramming HepG2 Hep3B cells. The zinc finger DHHC-type palmitoyltransferase 23 (ZDHHC23) plant homeodomain protein 2 (PHF2), subsequently enhancing ubiquitin-dependent degradation PHF2. This study...
Abstract Diabetes might be associated with increased cancer risk, several studies reporting hyperglycemia as a primary oncogenic stimulant. Since glucose metabolism is linked to numerous metabolic pathways, it difficult specify the mechanisms underlying hyperglycemia-induced progression. Here, we focused on polyol pathway, which dramatically activated under and causes diabetic complications. We investigated whether pathway-derived fructose facilitates gastric metastasis. performed...
A polymer ferroelectric array embedded in an insulating paraelectric medium, with potential uses nonvolatile memories, is fabricated by microimprinting poly(vinylidene fluoride) (PVDF) a patterned poly(dimethylsiloxane) mold. The localized pressure induces polymorphic transition into γ-type PVDF, whereas the unpressed raised areas (see figure) remain of α type (paraelectric).
We describe a simple route to fabricate two dimensionally well-ordered, periodic nanopatterns using the self-assembly of brush block copolymers (brush BCPs). Well-developed lamellar microdomains oriented perpendicular substrate are achieved, without modification underlying substrates, and structures with feature sizes greater than 200 nm generated due reduced degree chain entanglements BCPs. A near-perfect linear scaling law was found for period, L, as function backbone polymerization (DP)...
A simple, versatile approach to the directed self-assembly of block copolymers into a macroscopic array unidirectionally aligned cylindrical microdomains on reconstructed faceted single crystal surfaces or flexible, inexpensive polymeric replicas was discovered. High fidelity transfer line pattern generated from master mold is also shown. single-grained patterns over arbitrarily large surface areas without use top-down techniques demonstrated, which has an order parameter typically in excess...
One-dimensional photonic crystals based on the periodic stacking of two different dielectric layers have been widely studied, but fabrication mechanically flexible polymer structural color (SC) films, with electro-active switching, remains challenging. Here, we demonstrate free-standing electric field tunable ionic liquid (IL) swollen block copolymer (BCP) films. Placement a polymer/ionic film-reservoir adjacent to self-assembled poly(styrene-block-quaternized 2-vinylpyridine) (PS-b-QP2VP)...
Abstract Harmful effects of high fructose intake on health have been widely reported. Although is known to promote cancer, little about the underlying mechanisms. Here, we found that triggers breast cancer metastasis through ketohexokinase-A signaling pathway. Molecular experiments showed ketohexokinase-A, rather than ketohexokinase-C, necessary and sufficient for fructose-induced cell invasion. Ketohexokinase-A-overexpressing was be highly metastatic in fructose-fed mice. Mechanistically,...