Ki-Sub Kim

Molecular dynamics simulation study on capacitive nano-accelerometers based on telescoping carbon nanotubes

We investigated the characteristics of a capacitive nano-accelerometer based on a telescoping carbon nanotube by means of classical molecular dynamics simulations. The position of the telescoping nanotube was controlled by an externally applied force, and feedback sensing was based on the capacitance change. The capacitance variations, which were almost linearly proportional to the applied acceleration, were monitored within an error tolerance.

Unusual synergy effect on methane hydrate inhibition when ionic liquid meets polymer

We report the concept of combining ionic liquids (ILs) with polymer inhibitors to more effectively inhibit methane hydrate formation. The new inhibitors extended the induction time and decreased the growth rate of the hydrate. It was found that the presence of a hydroxyl group on IL provided the most powerful inhibition effect by forming hydrogen bonds between IL and water molecules.

Intertube spacing effect of cantilevered double-walled carbon nanotube resonators with short outer tubes

The vibrational properties of various double-walled carbon nanotube resonators were investigated via a classical molecular dynamics approach. The fundamental frequencies of double-walled carbon nanotube resonators with short outer tubes were closely related to the intertube spacing and the chirality of the outer tubes. Even though the length of the outer tube was 1 nm, the vibration of the outer tube affected that of the inner tube. For nanotubes with similar intertube spacing, both maximum frequencies were similar. For their corresponding maximum frequencies, the lengths of the outer tubes of the zigzag nanotubes were slightly less than those of the armchair ones.

Molecular dynamics simulation study of a carbon-nanotube oscillator in a graphene-nanoribbon trench

A graphene/carbon-nanotube (CNT) hybrid material can be useful in energy storage and nanoelectronic technologies. Here, we address a CNT oscillator encapsulated in a graphene-nanoribbon (GNR) trench as a novel design, and investigate its properties via classical molecular dynamics simulations. Because the energy barrier was very low while the CNT was encapsulated in the GNR trench, the CNT absorbed on the GNR surface could easily be encapsulated in the GNR trench. MD simulations showed that the CNT oscillator encapsulated in a GNR trench was compatible with simple CNT oscillators, so we anticipate that the CNT in the GNR trench could work as an oscillator. Thus, we can anticipate that the CNT encapsulated in a GNR trench can be applied to ultra-sensitive nanoelectromechanical oscillators and that this system has the possibility to be applied to relay-switching devices and to shuttle memories.

Size-selective Electrochemical Preparation of Alcohol Ionic-liquid-stabilized Palladium NPs

We have successfully synthesized morpholinium ionic-liquid-stabilized palladium nanoparticles by electrochemical reduction. The palladium nanoparticles (NPs) were characterized by using transmission electron microscopy and X-ray diffraction. The sizes of the particles produced could be controlled by adjusting the current density and the duration of the electrolysis. The particle sizes increased with decreasing current density and increasing electrolysis duration. X-ray diffraction of the resulting NPs indicated that the particles had a crystalline structure.