• Journal of Fashion Business
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• v.7 no.2
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• pp.69-81
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• 2003

Among the various properties of textile fabrics, the moisture-related properties are important for the textile processes or the apparel comfort characteristics. Alkaline hydrolysis results in pitting on the surface of fibers and increases the amount of hydroxyl and carboxyl end groups of the PET molecules on the fiber surface. The purpose of this study is to investigate the moisture-related properties of PET fabrics treated with quaternary ammonium compound/alkaline solution. The wetting and wicking properties of the PET fabrics were measured using the following experiments: contact angle, surface free energy, work of adhesion, vertical wicking height, moisture regain, and frictional static voltage. It was concluded that by the alkaline hydrolysis process, surface hydrophilicity and reactivity were considerably improved especially at lower levels of weight loss% and that the pitting of the fiber surface resulted in at higher levels of weight loss% was disadvantageous in moisture-related properties of PET.

• Advances in aircraft and spacecraft science
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• v.1 no.1
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• pp.1-14
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• 2014

Physico-chemical changes of the plasma modified titanium alloy [Ti-6Al-4V] surface were studied with respect to their crystallographic changes by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM).The plasma-treatment of surface was carried out to enhance adhesion of high performance nano reinforced epoxy adhesive, a phenomenon that was manifested in subsequent experimental results. The enhancement of adhesion as a consequence of improved spreading and wetting on metal surface was studied by contact angle (sessile drop method) and surface energy determination, which shows a distinct increase in polar component of surface energy. The synergism in bond strength was established by analyzing the lap-shear strength of titanium laminate. The extent of enhancement in thermal stability of the dispersed nanosilica particles reinforced epoxy adhesive was studied by Thermo Gravimetric Analysis (TGA), which shows an increase in onset of degradation and high amount of residuals at the high temperature range under study. The fractured surfaces of the joint were examined by Scanning electron microscope (SEM).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.7
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• pp.283-287
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• 2016

One of the most important factors for determining the thermal performance of an evaporative cooling system is the wettability of the evaporative heat exchanger surface. Evaporation of a widely spread water film on the heat exchanger surface promotes heat transfer between the "dry" air and "wet" air passages. Hydrophilic coating is generally applied on the heat exchanger surfaces to increase the wettability of the heat exchanger surface and the COP of the evaporative cooling system. In this paper, a simple lamellar patterned structure is suggested to maximize the spreading of a water film on the vertically oriented walls. The capillary height of the lamellar structured grooves is analyzed through a theoretical model, and the results are compared with the numerical analysis through a finite element analysis tool, SE-FIT. A good agreement between the theoretical model and the numerical analysis can be observed as long as the channel depth is comparable to or larger than the channel width of the lamellar structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.197-200
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• 2006

The ingress of chloride ions plays a crucial role for service life design of reinforced concrete structures. In view of durability design of concrete structures under marine environment, one of the most essential parameters is the surface chloride content of concrete. However, on the basis of the results of in-situ investigation, this value has been determining in the numerous studies on the durability design of concrete structures. Hence, it is necessary to confirm the range of the surface chloride content in order to establish a unified durability design system of concrete. This study suggests a rational and practical way to calculate the maximum surface chloride content of submerged concrete under marine environment. This approach starts with the calculation of the amount of chloride ingredients in normal sea water. The capillary pore structure is modeled by numerical simulation model HYMOSTRUC and it is assumed to be completely saturated by the salt ingredients of sea water. In order to validate this approach, the total chloride content of the mortar and concrete slim disc specimen was measured after the immersion into the artificial sea water solution. Additionally, the theoretical, the experimental and in-situ investigation results of other researchers are compiled and analyzed. Based on this approach, it will follow to calculate the maximum surface chloride content of concrete at tidal zone, where the environment can be considered as a condition of dry-wetting cycles.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.95-99
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• 1995

keV ion beam irradiatin for surface modification and thin film growth have been discussed. keV ion beam irradiation in reactive gas environment has been developed for improving wettability of polymer, and for enhancing adhesion to metal film, and adventages of the method have been reviewed. An epitaxial Cu film on Si(100) substrate has been grown by ionized cluster beam and changes of crystallinity and surface roughness have been discussed. Stoichiometric $SnO_2$ films on Si(100) and glass have been grown by a hybrid ion beam Deposition(2 metal ion sources+1 gas ion source), and nonstoichiometric $SnO_2$ films are controlled by various deposition conditions in the HIB. Surface modification for polymer by kev ion irradiation have been developed. Wetting angle of water to PC has been changed from 68 degree to 49 degree with $Ar^+$ irradiation and to 8 degree with $Ar^+$ irradiation and the oxygen environment. Change of surface phenomena in a keV ion beam and characteristics of the grown films are suggested.

• Textile Coloration and Finishing
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• v.16 no.5
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• pp.28-34
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• 2004

The polarizing film application exploits the unique physicochemical properties between PVA(Poly vinyl alcohol) film and CTA(Cellulose triacetate) film. However, hardly any research was aimed at improving the adhesion characteristics of the CTA film by radio frequency(RF) plasma treatment at argon(Ar) gaseous state. In this report, we deal with surface treatment technology for protective CTA film developed specifically for high adhesion applications. After Ar plasma, surface of the films is analyzed by atomic force microscopy(AFM), roughness parameter and peel strength. Furthermore, the wetting properties of the CTA film were studied by contact angle analysis. Results obtained for CTA films treated with a glow discharge showed that this technique is sensitive to newly created physical functions. The roughness and peel strength value increased with an increase in treatment time for initial treatment, but showed decreasing trend for continuous treatment time. The result of contact angle measurement refer that the hydrophilicity of surface was increased. AFM studies indicated that no considerable change of surface morphology occurred up to 3 minutes of treatment time, but a considerable uneven of surface structure resulted from treating time after 5 minutes.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.31-32
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• 2006

We describe the preparation of nanostructured molecularly-imprinted surfaces using nanomolding on porous alumina. In molecular imprinting functional and cross-linking monomers are copolymerized in the presence of a molecular template, resulting in synthetic receptor materials. The drug propranolol and the dye fluorescein were used as the molecular imprinting templates. Binding studies with imprinted and non-imprinted surfaces revealed specific recognition of the templates and thus the existence of selective binding sites. In addition, the surface properties of the films were studied by water contact angle measurements. It was found that, depending on the monomers used, certain nanostructures induced great changes in the wetting properties of the surface.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.791-797
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• 2002

This paper introduces the partial melting process for solder application and characterization of its feasibility using Sn-Ag, and Sn-Cu solder alloys. ill order to show that the liquid phase in the semi-liquid state maintains the similar wettability as single-phase liquid, the wetting balance tests are conducted with varying temperatures and compositions. Also, as a new soldering technology, the microstructural and mechanical test were investigated. The results from this research indicate that the partial melting can yield satisfactory sider joints as long as the liquid phase acquires sufficient chemical activity. At a condition where the partial melting is effective, a direct correlation between the wettability and the surface tension is found to exist.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1286-1289
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• 2008

We report on a wide-viewing liquid crystal (LC) display with bi-level microstructures spontaneously formed by selective wetting on a chemically heterogeneous surface. The bi-level microstructures serve as spacers for maintaining uniform cell gap, as well as protrusions for wide-viewing properties. Our LC cell having the bi-level microstructures shows good electro-optic properties.

• Progress in Superconductivity and Cryogenics
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• v.19 no.2
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• pp.9-13
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• 2017

This study presents a simple method to control the seed orientation which leads to the various growth characteristics of a single grain REBCO (RE: rare-earth elements) bulk superconductors. Seed orientation was varied systematically from c-axis to a-axis with every 30 degree rotation around b-axis. Orientations of a REBCO single grain was successfully controlled by placing the seed with various angles on the prismatic indent prepared on the surface of REBCO powder compacts. Growth pattern was changed from cubic to rectangular when the seed orientation normal to compact surface was varied from c-axis to a-axis. Macroscopic shape change has been explained by the variation of the wetting angle of un-reacted melt depending on the interface energy between $YBa_2Cu_3O_{7-y}$ (Y123) grain and melt. Higher magnetic levitation force was obtained for the specimen prepared using tilted seed with an angle of 30 degree rotation around b-axis.