• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.112-113
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• 2014

This study was done to resolve the air reduction in mortar when mixed with ERCO. Effects of the water repellent ALC powder due to its particle size and substitution ratio on the cement mortar with ERCO was analyzed. Results showed more water repellent ALC powder ensured more air but did not affect the size of particles. It was determined the compression was caused by more air and water added to achieve the flow. Therefore, substituting with water repellent ALC powder may compensate for the air reduction in mortar with ERCO. Other measures and approaches are needed in order to resolve the reduced strength.

• Proceedings of the Korean Fiber Society Conference
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.434-435
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• 2003

Physicochemical properties of a polymer surface significantly affect adhesion, wetting, and dyeing properties. In recent years, low temperature plasma technology has been widely used for surface modification of polymers. Surface fluorination by low temperature plasma treatment has been employed to improve the water and oily repellency of textile fabrics. However, very few results have been reported on soil release properties of the oxygen plasma treated textile fabrics. (omitted)

• Textile Coloration and Finishing
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• 제5권1호
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• pp.10-18
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• 1993

Epoxy compound was synthesized from bisphellol-A with epichlorophydrine. Epoxy compound and siloxane were emulsified conjugative one or another. The water repellency of silk fabrics was also highly improved by the treatment of epoxy-siloxane mixed emulsions containing stannic chloride and zirconium oxychloride. The maximum wrinkle recovery was obtained from the fabrics treated under the condition 2.5%-epoxy-siloxane emulsion at 16$0^{\circ}C$. The breaking elongation, the reflectance, the tensile strength and the bending properties of silk fabrics were not degraded severely by the treatment of epoxy-siloxane emulsion.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.63-64
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• 2023

In order to reduce the high absorption ratio of spent coffee grounds, this study examined the compressive strength and absorption ratio of mortar replacing coated spent coffee grounds according to the type of water repellent. In order to examine this, as the water repellent used, a silane-based water repellent (fluorine-based water repellent) and an acrylic-based water repellent, which are film-type water repellents, and a silane/siloxane-based water repellent, which are penetration-type water repellents, were used. The spent coffee grounds were coated with each of three water repellents, and mortar was prepared by mixing cement and fine aggregate. As a result of the experiment, the compressive strength and absorption ratio of the mortar replaced with coated spent coffee grounds coated with the film-type water repellent were superior to the penetration-type water repellent. Therefore, in order to reduce the high absorption ratio of spent coffee grounds, a suitable water repellent is a film-type water repellent. Among them, it is judged that the acrylic type has excellent water repellency and is suitable.

• Journal of the Korean Home Economics Association
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• 제20권3호
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• pp.19-24
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• 1982

This study was carried out to investigate the relationship between the water resistance and the air permeability. The results are as follows; 1. In case of the water proofing fabrics, We cannot find that there is any relationship between the water resistance and the air permeability according to the kinds of finishing, while in case of the water repellent finished fabries, we can find that there is a correlationship between them, especially the hydrostatic pressure and the air permeability are found to have negative correlation. 2. In case of the water proofing fabrics, the relationship between the water resistance and the air permeability is not affected by the thickness of the fabrics. On the other hand, in case of the water repellent finished fabrics, the relationship between them is affected by the thickness of the fabrics. Especially, the relationship between the hydrostatic pressure and the air permeability as well as the relationship between the water repellency and the air permeability is effect much by the thickness of the fabrics, too. 3. In case of the water proofing fabrics, the relationship between the water resistance and the air permeability is not affected by fabric count. On the otherhand, in case of the water repellent finished fabrics, the relationship between them is affected by the fabric count. Especially, the relationship between hydrostatic pressure and the air permeability, and the relationship between the water proof and the air permeability are affected much by fabric count.

• Journal of Sericultural and Entomological Science
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• 제27권2호
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• pp.28-39
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• 1985

The structural and useful characteristics of silk habutae treated with silicone resin by emulsion finishing method were studied. The results were obtained through crease recovery test, water repellency test, scanning micrograph observation, amino acid analysis, X-Ray diffraction analysis, and Fourier Transform Infrared Spectroscopy. The results are summarized as follows; 1) The improvement in crease recovery of silk habutae finished with silicone resin, was observed b soaping treatment and curing conditions. 2) The higher water repellency and stiffness in silk fabrics finished with silicone resin was found by the fabric inspection and the scanning electron microscopic observation. It is suggested that silicone resin impregnated into the void of silk fibroin. 3) The polar side chains of amino acid composition were decreased, when the silicone resin was treated on silk fibroin. 4) Through Amino acid analysis of silicone resin finished fibroin, the different amounts of amino acid composition was indicated due to silk fibroin silicone polymer reaction and the structural difference of its fibroin were also proved by X-ray diffractograms. 5) The functionality of the siloxane compound may be deduced from the silicone finished silk habutae by Fourier Transform Spectroscopy. It was concluded from the above results that the useful characteristics of silk fabric can be improved by silicone resin finishing.

• Korean Journal of Materials Research
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• 제23권1호
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• pp.53-58
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• 2013

Superhydrophobic $SiO_2$ layers with a micro-nano hierarchical surface structure were prepared. $SiO_2$ layers deposited via an electrospray method combined with a sol-gel chemical route were rough on the microscale. Au particles were decorated on the surface of the microscale-rough $SiO_2$ layers by use of the photo-reduction process with different intensities ($0.11-1.9mW/cm^2$) and illumination times (60-240 sec) of ultraviolet light. With the aid of nanoscale Au nanoparticles, this consequently resulted in a micro-nano hierarchical surface structure. Subsequent fluorination treatment with a solution containing trichloro(1H,2H,2H,2H-perfluorooctyl)silane fluorinated the hierarchical $SiO_2$ layers. The change in surface roughness factor was in good agreement with that observed for the water contact angle, where the surface roughness factor developed as a measure needed to evaluate the degree of surface roughness. The resulting $SiO_2$ layers revealed excellent repellency toward various liquid droplets with different surface tensions ranging from 46 to 72.3 mN/m. Especially, the micro-nano hierarchical surface created at an illumination intensity of $0.11mW/cm^2$ and illumination time of 60 sec showed the largest water contact angle of $170^{\circ}$. Based on the Cassie-Baxter and Young-Dupre equations, the surface fraction and work of adhesion for the micronano hierarchical $SiO_2$ layers were evaluated. The work of adhesion was estimated to be less than $3{\times}10^{-3}N/m$ for all the liquid droplets. This exceptionally small work of adhesion is likely to be responsible for the strong repellency of the liquids to the micro-nano hierarchical $SiO_2$ layers.

• Polymer(Korea)
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• 제27권6호
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• pp.528-535
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• 2003

The effects of surfactants, organic solvents, and functional monomers on the emulsion polymerization of perfluoroalkyleoylacryaltes and n-alkylacrylates were investigated. In particular, the dependence of the surface properties, contact angle and water repellency on the crystal melting temperature (T$\_$m/) of the fluorocopolymer and the variation of polymer latex particle sizes was investigated. Using WAXD experiments and synthesizing different types of fluorocopolymers which have fallowing fluoroacrylaytes [CH$_2$=CHCO$_2$CH,$_2$(CF$_2$CF$_2$) nH] (n = 4, 5 or 6), the relationship between the molecular packing structure of pendent side groups of fluorocopolymers and the surface properties was also investigated. We observed that the structure of primary carbon atoms of pendent side groups of fluorocopolymers plays key role in determining the surface properties.s.

• Proceedings of the KIEE Conference
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1651-1653
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• 1999

Room Temperature Vulcanizing (RTV) Silicone Rubber has been widely used to coat porcelain insulator to prevent formation water filming on insulator surface. and RTV silicone rubber has water repellency to suppress leakage current and consequent flashover. RTV silicone rubber's surface has been degradated by outdoor condition such as dust, salt, and water. etc. ESDD(Equivalent Salt Deposit Density) and leakage currents are increased by polymer surface toughness and degradation. In this paper, we investigated relations of surface toughness, ESDD, and leakage currents.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.6-8
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• 2001

This report describes the effect of the blending of poly(trifluoropropylmethylvinylsiloxane) (PTFPMVS) with poly(dimethylsiloxane) (PDMS) on the surface properties such as water repellency using dynamic contact angle (DCA) measurement. We have investigated the surface molecular mobility of the PDMS/PTFPMVS blends via a DCA measurement and an adhesion tension relaxation. It could be shown that a flexible side-chain segment in PTFPMVS having higher surface energy, could be reoriented easily in water to decrease the interfacial tension of the polymer/water interface, which seems to play a major role at the decrease of the receding contact angle and the surface resistivity of PDMS/PTFPMVS blends.