The potential of replacing crosslinked polyethylene (XLPE) with an eco-friendly alternative, polypropylene (PP), as insulating material is investigated for overhead power distribution lines. Although XLPE exhibits excellent electrical and mechanical properties, the byproducts generated during crosslinking pose environmental challenges. PP is a viable alternative because of recyclability and absence of byproducts during crosslinking. This study evaluated alternating current (AC) breakdown strength, contact angle, and tracking resistance of two commercially available XLPE samples and three types of PP (PP1, PP2, PP3) with varying additive content. AC breakdown strength, analyzed using the Weibull distribution, facilitated relative comparison of insulation performance. PP2 exhibited scale parameters comparable to or exceeding those of XLPE. Contact angles exceeding 90° displayed hydrophobicity across all samples. To address pass/fail evaluation limitations, arcing images from tracking tests were analyzed using the box-counting method for fractal dimension analysis. Fractal dimensions increased with arcing extent, and complexity increased with test duration. Tracking resistance performance order was PP3, PP1, CC, PP2, OC which was attributed to enhanced heat dissipation properties of filler additives. The proposed quantitative method for comparing tracking resistance through fractal dimension analysis, explored the feasibility of using PP insulating materials in overhead power distribution lines.

Currently, the most developed new energy source is solar energy. Because solar power is installed outside, it is exposed to many pollutants. Pollutants are causing the characteristics of solar energy to deteriorate. Therefore, this study aims to develop a water-repellent coating to prevent contamination of solar modules. Silica and Titania materials are mainly used as water-repellent coating materials. In this study, it was based on silica and the contact angle characteristics were measured according to the change in the amount of silica and ammonia water added and the number of coatings. As a result of the measurement, it was confirmed that the contact angle was more than 60 degrees when 0.5 mol of TEOS was added to 50 mL and 0.15 M when 1 mL of ammonia water was added to 296.47 ml of distilled water. And it was confirmed that the contact angle improved when the number of coatings was applied twice. A water-repellent coating material was applied to low iron tempered glass used to protect dye-sensitized solar cell modules. The characteristics of the module were measured after spraying DI-Water on low-emission tempered glass with a water-repellent coating. As a result of the measurement, the efficiency of the module without application, the efficiency of the module coated once, and the module coated twice were 4.87%, 4.90%, and 4.91%, respectively. It was confirmed that the efficiency of the module increased by applying water-repellent coating. As a result of this study, it is determined that the water-repellent coating material will help improve solar power generation efficiency and lifespan by being self-cleaning and non-reflective.

This paper introduces an optimized oxygen (O₂) plasma surface treatment technique to enhance sphere lithography on hydrophobic photoresist surfaces. The focus is on semiconductor manufacturing, particularly the creation of finer structures beyond the capabilities of traditional photolithography. The key breakthrough is a method that makes substrate surfaces hydrophilic without altering photoresist patterns. This is achieved by meticulously controlling the O₂ plasma treatment duration. The result is the consistent formation of nano and microscale patterns across large areas. From an academic perspective, the study deepens our understanding of surface treatments in pattern formation. Industrially, it heralds significant progress in semiconductor and precision manufacturing sectors, promising enhanced capabilities and efficiency.

We investigated the properties of vanadium oxide (VOx) buffer layers deposited by a dual RF magnetron sputtering method under various target powers for inverted organic solar cells (IOSCs). Sputter fabricatged VOx thin films exhibited higher crystallinity with the increase of target power, resulting in a uniform and large grain size. The electrical properties of VOx films are improved with the increase of target power because of the increase of V content. In the results, the performance of IOSCs critically depended on the target power during the film growth because the crystalllinity of the VOx film affects the carrier mobility of the VOx film.

Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

In this study, we tried finding new materials to improve the stain resistance properties of polymer insulating materials. Using the filtered vacuum arc source (FVAS) with a graphite target source, DLC thin films were deposited on silicon and polymer insulator substrates depending on their thickness to confirm the surface properties, physical properties, and structural properties of the thin films. Subsequently, the possibility of using a DLC thin film as a protective coating material for polymer insulators was confirmed. DLC thin films manufactured in accordance with the thickness of various thin films exhibited a very smooth and uniform surface. As the thin film thickness increased, the surface roughness value decreased and the contact angle value increased. In addition, the elastic modulus and hardness of the DLC thin film slightly increased, and the maximum values of elastic modulus and hardness were 214.5 GPa and 19.8 GPa, respectively. In addition, the DLC thin film showed a very low leakage current value, thereby exhibiting electrical insulation properties.

The wettability of silicon carbide (SiC) crystal, which has 6H-SiC and 4H-SiC regions prepared using the physical vapor transport (PVT) method, is quantitatively analyzed using dispensed deionized (DI) water droplets. Regardless of the polytypes in SiC, the average of five contact angle measurements showed a difference of about 6° between the Si-face and C-face. The contact angle on the Si-face (C-face) is measured after the removal of the native oxide using BOE (6:1), and revealed a significant decrease of the contact angle from 74.9° (68.4°) to 47.7° (49.3°) and from 75.8° (70.2°) to 51.6° (49.5°) for the 4H-SiC and 6H-SiC regions, respectively. The contact angle of the Si-face recovered over time during room temperature oxidation in air; in contrast, that of the C-face did not recover to the initial value. This study shows that the contact angle is very sensitive to SiC surface polarity, specific surface conditions, and process time. Contact angle measurements are expected to be a rapid way of determining the surface polarity and wettability of SiC crystals.

Inductively coupled plasma (ICP) treatment with argon and a mixture of argon and oxygen gases has been used to modify the surface of polycarbonate (PC) substrates. The results showed that the surface contact angle was inversely proportional to the plasma discharge power and that the mixed-gas plasma (gas flow 10:10 sccm, discharge power 60 W) decreased the surface contact angle as low as 18.3°, indicating a large increase in the surface hydrophilicity. In addition, SnO₂ thin films deposited on the PC substrate effectively enhanced the ICP plasma treatment, and could also enhance the usefulness of PC in the inner parts of automobiles.

Titanium oxide (TiO2) thin films were synthesized on polymer insulator and Si substrates by atomic layer deposition (ALD) method. The surface and electrical properties of TiO2 films synthesized at various ALD cycle numbers were investigated. The synthesized TiO2 films exhibited higher contact angle and smooth surface. The contact angle of TiO2 films was increased with the increase of ALD-cycle number. Also, the rms surface roughness of films was slightly rough with the increase of ALD-cycle number. The leakage current on TiO2 film surface synthesized at various conditions were uniformed, and the values were decreased with the increase of ALD-cycle number. In the results, the performance of TiO2 films for self-cleaning critically depended on a number of ALD-cycle.

Titanium oxide (TiO2) thin films were fabricated by unbalanced magnetron (UBM) sputtering. The fabricated TiO2 films were treated by oxygen plasma under various RF powers. We investigated the characteristics of oxygen plasma treatment on the surface, structural, and physical properties of TiO2 films prepared at various plasma treatment RF powers. UBM sputtered TiO2 films exhibited higher contact angle value, smooth surface, and amorphous structure. However, the rms surface roughness TiO2 films were rough, and the contact angle value was decreased with the increase of the plasma treatment RF power Also, the hardness value of TiO2 film as physical properties was slightly increased with the increase of the plasma treatment RF power. In the results, the performance of TiO2 films for self cleaning critically depended on the with the plasma treatment RF power.

WO3, SiO2, and TiO2 films with hydrophilic property are deposited by rf-magnetron sputtering. Their wettability is strongly depends on the presence or absence of the oxygen plasma etching on the glass substrates. The TiO2 film of 50 nm-thick on the plasma etched glass shows a water contact angle (WCA) below 5o which means a super-hydrophilic surface. However, WCA values are gradually degraded when the films are exposed under atmosphere, especially WO3. In order to improve hydrophilic property, the degraded films can be again recovered by UV illumination for 10 sec using UV-light and the TiO2 film shows a super-hydrophilic surface about 3o.

An excellent hydrophobic surface has a high contact angle over 147 degree and the contact anglehysteresis below 50 was produced by using roughness combined with hydrophobic PTFE coatings, which were alsoconfirmed to exhibit an extreme adhesion to glass substrate. To form the rough surface, the glass was etched byAr-plasma. A very thin PTFE film was coated on the plasma etched glass surface. Roughness factors before orafter PTFE coating on the plasma etched glass surface, based on Wensel``s model were calculated, which agreeswell with the dependence of the contact angle on the roughness factor is predicted by Wensel``s model. The PTFEfilms deposited on glass by using a conventional rf-magnetron sputtering. The glass substrates were etchedAr-plasma prior to the deposition of PTFE. Their hydrophobicities are investigated for application as a anti-foulingcoating layer on the screen of displays. It is found that the hydrophobicity of PTFE films mainly depends on thesputtering conditions, such as rf-power, Ar gas content introduced during deposition. These conditions are closelyrelated to the deposition rate or thickness of PTFE film. Thus, it is also found that the deposition rate or the filmthickness affects sensitively the geometrical morphology formed on surface of the rf-sputtered PTFE films. Inparticular, 1,950-nm-thick PTFE films deposited for 30 minute by rf-power 50 watt under Ar gas content of 20sccm shows a very excellent optical transmittance and a good anti-fouling property and a good durability.

In this paper, we present a novel hydrophilic coating material (Wellture Finetech, Korea) which can be utilized as a coating layer for anti-contamination for electrical and electronic system. The coating material was deposited on 4 inch silicon wafer with several different film thickness. The film thickness was controlled by spin coating speed. After curing of the film, we have scratched by permanent marker to check self-cleaning property of the film. Also we have executed several mechanical tests of the films. As the spin coating speed is increased, the film thickness was thickness was thinned from 230 nm to 125nm. Contact angle of the film lowered from 30° to 12° as the spin coating speed is increased from 700 to 2,500rpm. On permanent marker scratched film surface coated at 1,000 rpm. We have poured regular city water to investigate self cleaning property of the film. The scratches were gradually separated from the film surface due to super-hydrophilicity of the film. Hardness of coated film was 9H measured by ASTM D3363 method. And adhesion of all film was 5B tested by D3359 method. Also, to get exact hardness value of the film, we have utilized a nano-indenter. As spin speed is increased, the hardness of film was increased from 3 Gpa to 5 Gpa.

In this study, we have coated the inner surface of YSZ channel using LSM powder ink through depressurization process for making the cathode of a stacked planar-type SOFC module. To coat the surface of YSZ channel uniformly, we tried to find the optimum manufacturing condition for LSM ink. We used four different dispersants (BYK series) and two different solvents (ethanol and DMF) to make the LSM ink. It was revealed that the ink made with the ethanol solvent and the BYK-111 dispersant has the lowest viscosity, relatively low contact angle and most excellent dispersibility. After depressurizing a chamber filled with LSM ink and sintered YSZ channel, we have found that the YSZ channel was uniformly coated with LSM cathode. The LSM ink with 25 vol% BYK-111 showed the most uniform coating.

In this study, the surface modification for a silicon(Si) mold using CHF3 inductively coupled plasma(ICP). The conditions under that plasma was treated a input ICP power 600 W, an operating gas pressure of 10 mTorr and plasma exposure time of 30 sec. The Si mold surface became hydrophobic after plasma treatment in order to CF(x)(X= 1,2,3) polymer. However, as the de-molding process repeated, it was investigated that the contact angle of Si surface was decreased. So, we attempted to investigate the degradation mechanism of the accurate pattern transfer with increasing the count of the de-molding process using scanning electron microscope (SEM), contact angle, and x-ray photoelectron spectroscopy (XPS) analysis of Si mold surface.

Super-hydrophobic properties have been achieved on the rf-sputtered polytetrafluoroethylene(PTFE) films deposited on etched aluminum surfaces. The microstructural evolution created after etching has been investigated by FESEM. The water contact angle over 160o can be achieved on the rf-sputtered ultra-tihn PTFE film less than 10 nm coated on aluminum surface etched with 7 wt.%, 12.5 wt.%, and 15 wt.% HCl concentration for 12 min. XPS analysis have revealed the presence of a large quantity of -CF3 and -CF2 groups in the rf-sputtered PTFE films that effectively can reduce the surface energy of etched aluminum. The presence of patterned morphology along with the low surface energy at the rf-sputtered PTFE coating makes the aluminum surface with high super-hydrophobic property.