Jo May 15, 2026
Recently, PbO2 electrodes with high oxygen overpotential, good electrical conductivity and electrocatalytic property have been widely used as anode in electrochemical industries such as electrowinning of metals, lead acid batteries, analytical sensors, electrochemical synthesis of peroxides and electrochemical treatment of wastewater, etc.
PbO2 is divided into two types, namely, α-PbO2 in the orthorhombic form and β-PbO2 in the tetragonal form. The anode material PbO2 is prepared by electrodeposition. α-PbO2, which is mainly electrodeposited in alkaline electrolyte, is used as an intermediate layer to enhance the performance of β-PbO2 on the substrate. β-PbO2 electrodeposited in acid solutions has good electrochemical properties such as electrical conductivity and active surface area, and it is considered as an alternative anode material for platinum or RuO2 electrodes. Pure β-PbO2 electrodes have not been durable when used at high voltages because they have low electrocatalytic activity. Therefore, many studies have been carried out to improve the stability, service life and adhesion of PbO2 electrodes. However, few papers have reported the changes in the stability, service life, electrochemical activity, etc. of electrodes depending on dispersants. Dispersants are often used in electrodeposition because they improve the surface property and adhesion of PbO2 layers.
Paek Yong Sok, a researcher at the Faculty of Chemical Engineering, prepared stainless steel (SS)/α-PbO2/β-PbO2 electrodes with improved surface states and electrocatalytic activity using cerium and dispersants sodium dodecyl sulfate (SDS) and polyvinyl alcohol (PVA), and evaluated the electrochemical properties of electrodes depending on the dispersants. He determined the service life of electrodes by accelerated life tests and electrooxidized Ce3+ in rare earth sulfate solution, using the prepared SS/α-PbO2/β-PbO2 electrodes.
The electrode prepared by the addition of SDS and PVA together had the longest life time 525h. Using the SS/α-PbO2/β-PbO2 electrode, 95% of cerium was oxidized at a current density of 20mA/cm2 for 37h. The current efficiency was more than 87% and the power consumption was the lowest, 1.8kW･h/kg.
For more information, please refer to his paper “Preparation of Stainless Steel/α-PbO2/β-PbO2 Electrode and its Application for Electrooxidation of Cerium” in “Proceedings of KUTIC-2025”.
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Jo May 14, 2026
Graphene is a very promising material for real applications due to its unique properties and special structure. The methods of graphene preparation include mechanical exfoliation, silicon carbide epitaxy, chemical vapor deposition, redox and laser-induced graphene (LIG). Among them, LIG is a very promising graphene preparation method due to its advantages such as low fabrication cost, simple fabrication and low environmental pollution.
Some researchers have conducted basic studies of LIG applications including hydrogen-generating electrodes, supercapacitors and various sensors. To date, however, no research has been published on the optimal parameter selection and the influence of these parameters on the properties of LIG.
Jang Il San, a researcher at the Institute of Nano Science and Technology, has investigated the effect of laser power and scanning speed on LIG formation when CO2 laser is irradiated on polyimide films.
First, he developed a theoretical model to get temperature field distribution on the film when CO2 laser is irradiated on a polyimide film. Then, he calculated the temperature distribution inside the laser beam focus spot at different laser powers and scanning rates using COMSOL Multiphysics. After that, he determined the laser power and scanning speed range for LIG formation, and prepared graphene samples accordingly.
The simulation of the temperature field on the polyimide film during LIG fabrication showed that the temperature at which graphene is formed is above 2 800K at the depth of about 0.025mm.
If further information is needed, you can refer to his paper “Effect of Laser Power and Scanning Speed on Properties of Laser-Induced Graphene” in “Proceedings of KUTIC-2025”.
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Jo May 13, 2026
As a kind of fibre, regular textile fabric is considered a porous medium composed of a lot of thread. Thread itself is also a porous medium. In other words, regular textile fabric corresponds to a large-pore porous medium composed of small-pore matrix (thread).
Heat and mass transfer problems in porous media have been studied in two categories: equilibrium and non-equilibrium. Some studies focused on the numerical simulation of the problems involving non-equilibrium heat and mass transfer.
Choe Song Gun, a section head at the Faculty of Thermal Engineering, has developed a mathematical model of fluid flow and non-equilibrium heat and mass transfer in porous media.
First, he presented governing equations for fluid, solid and porous regions and he paid special attention to moisture transfer from porous media to the surrounding moist air flow. Then, he described a CFD solution approach for spatially distributed temperature and moisture content in regular textile fabric during drying. User-Defined Scalar (UDS) and User-Defined Function (UDF) were used.
Finally, he conducted an unsteady simulation of drying of porous media placed in the 2D channel by using FLUENT, and analysed the effects of temperature and velocity at the inlet and the porosity and diffusion coefficient of porous media on drying.
For more information, please refer to his paper “CFD Simulation of Convective Drying of Regular Dual Porosity Media Under Local Non-Equilibrium” in “Proceedings of KUTIC-2025”.
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Jo May 12, 2026
Dissimilar joints between steel and copper alloys are widely used in aerospace, mechanical, electrical, metallurgical and refrigeration industries because of their high strength and thermal conductivity, good mechanical properties and electrical conductivity, high corrosion resistance and low cost.
It is difficult to weld steel and copper alloys because the physical properties such as their melting points, coefficients of heat conductivity and coefficients of thermal expansion are different. It is particularly difficult to weld brass to other metal because evaporation of zinc during welding makes the weld porous.
To get a sound weld of brass, it is necessary to keep the heat input as low as possible. Then, it helps formation of a small heat affected zone (HAZ) in the weld and helps protect the welding zone against the surrounding medium. Another method used to limit the heat input into the welding pool in the welding of brass materials is to use filler materials. When these are used, the arc is concentrated on the filler material, which reduces Zn loss from the brass to be welded.
Taking it into consideration, Kim Tae Hong, a section head at the Faculty of Material Science and Technology, performed butt braze welding of brass tube to steel plate using TIG welding by selecting appropriate welding currents and arc positions, and evaluated the characteristics of the joints.
No pore was found in the joint at the welding current of 70A and different arc offset, and no crack was found in the joint after 300 times of thermal cycle. In addition, a sound joint was formed without evaporation of zinc when the arc position was inclined towards the side of steel.
You can find more information in his paper “Study on the TIG Welding of Brass to Steel” in “Proceedings of KUTIC-2025”.
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Jo May 11, 2026
The key of dimethyl ether to olefins (DTO) technology is to synthesize catalysts with high selectivity of light olefins and long lifetime. Crystalline silicoaluminophosphates (SAPO) are microporous material with many applications. SAPO-18 (with AEI framework topology) is a solid acid catalyst with microporous structure that is extensively used in the processes of methanol to olefins (MTO), DTO, CO2/CH4 separation and selective catalyst reduction (SCR) of NOx, and it is structurally similar to SAPO-34 (with CHA framework). However, the drawback of these catalysts in MTO or DTO is rapid deactivation.
Many attempts have been made to enhance the catalytic performance and lifetime of SAPO-18, but the effect of post-acid treatment on DTO performance of SAPO-18 has been barely addressed.
Ho Yu Gyong, a researcher at the Institute of Nano Science and Technology, proposed post-HCl treatment as a method for improving DTO performance of SAPO-18 in DTO reactions and compared the catalytic performances such as crystalline structure, morphology, textural properties, acidity and DTO performance.
She investigated the effect of post-treatment with hydrochloric acid (1-5h with 0.01-0.2M HCl) to improve the catalytic performance of hydrothermally synthesized SAPO-18 (S-0). The microporous surface area of S-0.1-3 (S-0 treated with 0.1M HCl for 3h) was 642m2/g, and the pore channel entrance of crystal surface was extended. The single-run lifetime in DTO was prolonged by 1.5-1.7 times that of S-0 while the light olefins selectivity was increased by about 11%.
For more information, please refer to her paper “Improved DTO Performance after HCl Treatment of SAPO-18” in “Proceedings of KUTIC-2025”.
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Jo May 10, 2026
Graphene, which has been studied since 2004, has been widely used in metal-based composites as a very hard reinforcing phase due to its excellent properties. In addition to high strength and high conductivity, graphene reinforced aluminum matrix composites (AMCs) have proved to be lighter, cheaper and better than Cu matrix composites and various aluminum alloys in automotive and aerospace fields.
However, there are still some problems for practical application. Low wettability and dispersibility that have been a challenge for graphene-reinforced metal-matrix composites are also present in aluminum/graphene composites. It means poor interfacial adhesion between graphene and aluminum. Therefore, higher adhesion of the Al/graphene (Al/G) interface is essential to improve the properties of Al-based composites.
Since the surface lattice parameters of copper or nickel are less different from those of graphene than those of aluminum, pre-coating of these metals improves the bonding properties.
Taking it into consideration, Jon Sin Hyok, a researcher at the Faculty of Material Science and Technology, conducted a first-principles study of the interfacial bonding, mechanical strength and electronic properties of copper-doped graphene-Al (Al/Cu/G) composites using several superlattice models with different graphene contents.
The calculation results show that weak chemical bonding due to orbital hybridization between the coated copper and graphene layers is formed, and that the bonding is relatively strong compared to the bonding between Al and graphene layers without Cu, and the bond strength decreases gradually with increasing graphene content.
You can find the details in his paper “First Principle Study on Mechanical and Electronic Properties of Cu Doped Graphene Reinforced Al Composite” in “Proceedings of KUTIC-2025”.
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