• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.256-261
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• 2018

Recently, the number of cardiovascular disease-related deaths worldwide has increased. Therefore, the importance of percutaneous cardiovascular intervention and drug-eluting stents (DES) has been highlighted. Despite the great clinical success of DES, the re-endothelialization at the site of stent implantation is retarded owing to the anti-proliferative effect from the coated drug, resulting in late thrombosis or very late restenosis. In order to solve this problem, studies have been actively carried out to excavate new drugs that promote rapid re-endothelialization. In this study, we introduced hydrophilic drug, tauroursodeoxycholate (TUDCA), that improves the proliferation of endothelial progenitor cells and promotes apoptosis of vascular smooth muscle cells. In addition, we utilized shellac, which is a natural resin from lac bug to coat TUDCA on the surface of the metal. When using conventional coating method including biodegradable polymers and organic solvents, phase separation between polymer and drug occurred in the coating layer that caused incomplete incorporation of drug into the polymer layer. However, when using shellac as a coating polymer, no phase separation was observed and drug was fully covered with the polymer matrix. In addition, by adjusting the composition of coating solution and modifying the hydrophilicity of the metal surface using oxygen plasma, the surface roughness decreased due to the increased affinity between coating solution and metal surface. This result provides a method of depositing a hydrophilic drug layer on the stent.

• Fashion & Textile Research Journal
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• v.2 no.3
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• pp.220-226
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• 2000

This study was to determine the characteristics of vapor-permeable waterproof finished fabric by the coating method. 4 different kinds of coating fabrics (A : wet, porous, polyurethane, B : dry, no porous, polyurethane, C : shape memory polyurethane and D : dry, porous polyurethane) were used, which were developed recently With this sample, moisture transport rate ($40^{\circ}C$, 45%RH & $40^{\circ}C$, 95%RH), changes of coating side's shape by washing times, water repellency rate, contracted length, qmax, heat conductivity, heat keeping rate, heat keeping rate with cotton, heat keeping rate on humidity temperature and humidity within clothing etc. were checked. And it was done in a climate chamber under $20{\pm}2^{\circ}C$, $65{\pm}5%RH$. The results of this study were as follow; In the moisture vapor transmission of sample B and C increased on high temperature and high humidity while sample A and D decreased, on this condition. Qmax rate had high relation with ground fabric's surface properties and the order was A>C>D>B. Heat conductivity had high relation with thickness and surface properties. Heat keeping rates on sweat condition showed around half percents of heat keeping rates on normal condition, but had no relation with moisture vapor transport rate. Changes of the fabric's properties by washing times were different in accordance with the construction of fabrics and the coating resin. Sample C had tow heat keeping rate on the high temperature and humidity and high heat keeping rate on the low temperature and humidity Moisture transport rate of vapor-permeable waterproof finished fabrics had high relation with the properties of ground fabrics on low humidity condition, but on the high humidity condition, it was highly related with the properties of coating resin.

• Journal of Adhesion and Interface
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• v.10 no.4
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• pp.155-161
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• 2009

The most upcoming technical issue of automotive coating is the compact coating process. Pre-primed coating is the outstanding technology eliminating electro-deposition and primer coating process. The main properties of pre-primed coating for automotive are flexibility, corrosion resistance, and weldability. Therefore, we synthesized the conventional polyester, elastomeric polyester and polyvinylidene fluoride resins and evaluated their properties to use as weldable pre-primed automotive coatings. As the results of flexibility and curing behavior, the elastomeric polyester coating was most appropriate to use for the pre-primed automotive coatings.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.105-111
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• 2024

The SLA (Stereolithography Apparatus) method is a type of 3D printing technique predicated on the transformation of liquid photocurable resin into a solid form through UV laser exposure, and its application is increasing in various fields. In this study, we conducted research to enhance the hydrophobicity and transparency of SLA 3D printing surfaces for microfluidic system production. The enhancement of surface hydrophobicity in SLA outputs was attainable through the application of hydrophobic coating methods, but the coating durability under different conditions varied depending on the type of hydrophobic coating. Additionally, to simultaneously achieve the required transparency and hydrophobic properties for the fabrication of microfluidic systems, we applied hydrophobic coatings to the proposed transparency enhancement method from prior research and compared the changes in contact angles. Teflon coating was proposed as a suitable hydrophobic coating method for the fabrication of microfluidic systems, given its excellent transparency and high coating durability in various environmental conditions, in comparison to titanium dioxide coating. Finally, we produced an Electrophoresis of Charged Droplet (ECD) chip, one of the digital microfluidics systems, using SLA 3D printing with the proposed Teflon coating method (Fluoropel 800). Droplet manipulation was successfully demonstrated with the fabricated chip, confirming the potential application of SLA 3D printing technology in the production of microfluidic systems.

• The Journal of Advanced Prosthodontics
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• v.1 no.2
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• pp.68-74
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• 2009

STATEMENT OF PROBLEM. When veneering composite resin-metal restoration is prepared, the fact that bond strength between Ti and composite resin is relatively weak should be considered. PURPOSE. The purpose of this study is to evaluate the shear bond strength between the veneering composite resin and commercial pure (CP) Ti / Ti-6Al-4V alloy according to the method of surface treatment. MATERIAL AND METHODS. The disks were cast by two types of metal. Their surfaces were treated by sandblasting, metal conditioner, TiN coating and silicoating respectively. After surface treatment, the disks were veneered by composite resin (Tescera$^{TM}$, Bisco, USA) which is 5 mm in diameter and 3 mm in thickness. The specimens were stored in water at $25^{\circ}C$ for 24 hours, and then evaluated for their shear bond strength by universal testing machine (STM-$5^{(R)}$, United Calibration, USA). These values were statistically analyzed. RESULTS. 1. All methods of surface treatment were used in this study satisfied the requirements of ISO 10477 which is the standard of polymer-based crown and bridge materials. 2. The metal conditioner treated group showed the highest value in shear bond strength of CP Ti, silicoated group, TiN coated group, sandblasted group, in following order. 3. The silicoated group showed the highest value in shear bond strength of Ti-6Al-4V alloy, metal conditioner treated group, sandblasted group, TiN coated group, in following order. CONCLUSION. Within the limitations of this study, all methods of surface treatment used in this study are clinically available.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.608-613
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• 2010

This study is on development of UV-cured water soluble coating composition which have more improved anti-cigar burning to prevent a surface of PVC tile from damage of heat. To make an anti-cigar burning coating solution, thermostable agent that synthesize main materials phosphorus compound, guanidine and ammonium phosphate dibasic used temporary flame retardants, changing their contents from 10 to 30wt% against quantities of resin and compounded. After coating PVC tiles using bar-coating method that can adjust a thickness, we estimated surface properties of coated layer such as anti-cigar burning, adhesive power, chemical resistance, thickness of coating, and so on. Results showed that a coating composition added 30 wt% of phosphorus compound and coated with No.12 bar-coater had the best optimized surface property in anti-cigar burning effect, adhesive power and chemical resistance. Also, we could find anti-cigar burning effect was improved as thermostable agents content and coating thickness increased.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.226-232
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• 2019

The purpose of this study was to investigate the effect of adding a protective coating on the microhardness and wear resistance of glass ionomer cements (GICs). Specimens were prepared from GIC and resin-modified GIC (RMGI), and divided into 3 groups based on surface protection: (1) no coating (NC), (2) Equia coat coating (EC), and (3) un-filled adhesive coating (AD). All specimens were then placed in distilled water for 24 h. Surface hardness (n = 10) was evaluated on a Vickers hardness testing machine. Wear resistance (n = 10) was evaluated after subjecting the specimen to thermocycling for 10,000 cycles using a chewing simulator. Data were analyzed using a one-way ANOVA and the Kruskal-Wallis test. Surface hardness was highest in the NC groups, followed by the EC and AD groups. The wear depth of GI + NC was significantly higher than that of all RMGI groups. EC did not significantly lower the wear depth compared to AD. Based on these results, it was concluded that although EC does not increase the surface microhardness of GIC, it can increase the wear resistance.

• Tribology and Lubricants
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• v.35 no.2
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• pp.87-93
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• 2019

This work aims to develop a dry lubricant for oilless bush, especially a solid lubricant, thereby creating a coating method with improved properties of anti-friction and load-carrying capacity without oil lubrication. In this work, spherical-shaped powders of thermosetting resin such as polyimide (PI) are mixed with a binder matrix obtained by mixing a fluorocarbon compound resin such as Polytetrafluoroethylene (PTFE) or Ethylene tetra fluoro ethylene (ETFE) with itself or with a non-fluorocarbon thermoplastic resin such as Polyether ether ketone (PEEK). And these dry lubricant mixtures are thickly coated (200-300 mm in the thickness) on the inner surface of the bush by using a wet-typed air-spray deposition method. It was found that the load-carrying capacity of the solid lubricant for excavator bush (60 mm in diameter) that operates under a high load condition (at 40 MPa) is greatly improved owing to the spherical-shaped powders of thermosetting resin. In addition, the coefficient of friction at the sliding surface is also reduced less than 0.1. Thick coating also lowers the contact stress at the edge of a bush that results in better tribological performances. The result suggests that the lubrication performance and durability life of the bush can be remarkably improved even without lubrication (oil or grease).

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.513-518
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• 2003

Recently, advanced systems for water treatment are introduced for water quality improvement. One of those systems is water treatment method using ozone($O_3$). For it has strong oxidizing energy, it is necessary to have materisl stability against $O_3$. In this paper, epoxy resin specimens using as anticorrosive material of concrete structure for drink water are used to serve as a material of deterioration evaluation. It is to be studied weight loss, surface corrosion of specimens, ingredient analysis of floating particle, a solute of chemical ingredient by way of accelerated ozone testing. As the results of experiment, specimen weight is decreased. The surface of specimen is eroded heavily and showed a loss of gloss and floating particle, and in the stability for drinking water, harmful ingredient is not detected in the water.

• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.553-559
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• 2008

The purpose of this research was to compare the microtensile bond strength of resin coated surface and resin inlay according temporary filling materials prior to applying self-adhesive resin cement. Caviton(GC, Japan), Provifil(Promedica, Neumunster, Germany), Provifil(Promedica, Neumunster, Germany) & petrolatum, and Eugenol-based cement, Tembond(Kerr, Orange CA, USA) were used as temporary filling materials. After fabrication of Tescera(Bisco, Schamburg IL, USA), it was bonded with a self-adhesive resin cement, Rely X unicem(3M, St. Paul. Minn, USA). After this procedure, the microtensile bond strength was measured and it was analyzed through one-way ANOVA and Duncan test(p<0.05). Caviton(GC, Tokyo, Japan) showed statistical difference except for the control(group I) and the saliva(group II)(p<0.05). Provifil(group IV), Provifil & petroneum(group V), Tembond(group VI) had lower microtensile bond strength.