Jae-Min Oh

Synaptic functions of ionic liquid-gated P3HT surface-capped perovskite transistors with optimized NiO _x nanoparticle additives is investigated. Various characteristic synaptic behaviors are effectively mimicked in ionic liquid-gated devices.

The inner lumen of the polyurethane tube is modified with titanium dioxide particles and polyethylene glycol chains to create an anti-biofouling tracheostomy tube with integrated physical, chemical, and mechanical functionalities. The surface of tube is initially midified with titanium dioxide particles utilizing polyurethane binder via dip-coating, followed by further functionalization with polyethylene glycol chains. The infrared spectrum confirms that all coating components are securely attached to the inner lumen of medical tube. Scanning electron microscopy and surface hardness tests validate that the coated layer is highly homogeneous, containing various coating agents, and remains stable under mechanical stimulation. The extraction test, conducted according to International Standards Organization guideline, indicates no significant release of the coated agents under physiological conditions; additionally, the extract shows neither cytotoxicity against bronchial cells nor sensitization on animal skin. By achieving a physically roughened surface, chemically modifying with titanium dioxide, and adding a mechanical repellent in the form of polyethylene glycol chains, the surface of tube acquires comprehensive antifouling properties. Consequently, the coated tube exhibits up to an 85.54 % reduction in biofouling compared with a bare polyurethane tube.

Flexible and high-performance sodium-ion storage systems are essential for next-generation energy technologies. Here, orthorhombic K(VO₂)₂(PO₄) nanostructures were synthesized on carbon cloth through a controlled phosphorization process for 4 h (4KVOP-C). The 4KVOP-C electrode exhibited a fibrous network morphology, providing abundant active sites, short Na⁺ diffusion pathways, and strong contact with the conductive substrate. Moreover, its robust P–O bonds and open ion-diffusion channels enhanced its structural stability and charge transport. The 4KVOP-C electrode delivered outstanding electrochemical performance, with a high areal capacitance and excellent rate capability in a three-electrode configuration. The phosphate-stabilized vanadyl framework of KVOP enables delocalized charge redistribution across the V–O–P networks during Na adsorption, resulting in a higher quantum capacitance and density of states at the Fermi level. This electronic preconditioning underlies its superior areal capacitance, fast charge–discharge, and enhanced Na-ion accommodation compared with those of potassium-intercalated vanadium oxide. Moreover, a symmetric 4KVOP-C//4KVOP-C supercapacitor was assembled, which operated over a wide voltage window of 2.0 V, achieving an energy density of 50 µW h cm⁻² at a power density of 1980 µW cm⁻², along with excellent cycling stability. These results demonstrate that the fibrous K(VO₂)₂(PO₄) nanostructures synthesized via optimized phosphorization exhibit excellent intrinsic electrochemical properties, making them potential electrode materials for flexible, high-energy-density and durable sodium-ion supercapacitors.

Au-decorated NiCoLDH synthesized via the sol–gel method (Au@NiCoLDH-EG) showed rapid 4-NP reduction to 4-AP in 3.5 min and improved HER performance due to accelerated electron and charge transfer.

The molecular weight of PEI governs Ti–N bonding, stability, and biocompatibility of MXene hybrids, achieving strong oxidation resistance and high cellular uptake.

This study develops a new type of fluorinated covalent organic nanosheets (CONs) as anode materials for sodium‐ion batteries by incorporating an electron‐withdrawing benzothiadiazole (BT) unit and F atom into the framework. These modifications lead to a reduced bandgap and electron density, generating strong permanent dipoles that increased Na ⁺ accessible sites within the self‐assembled solid‐state structure. To elucidate the effect of these electronic changes, the Na ⁺ storage performance of fluorinated D/A‐CON‐10‐F is compared to that of nonfluorinated D/A‐CON‐10. The reduced electron density in D/A‐CON‐10‐F weakens its interaction with Na ⁺ , yet enhances ion and charge carrier conductivities, leading to improved electrochemical performance. Notably, D/A‐CON‐10‐F exhibits a reversible discharge capacity of ≈637 mA h g ⁻¹ at 100 mA g ⁻¹ , maintaining structural stability over 5000 cycles with excellent rate capability. These results demonstrate that dipole engineering in CONs effectively enhances charge transport and long‐term stability, offering a promising strategy for next‐generation sodium‐ion battery anodes.