• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.51-58
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• 1995

To prepare a durable softening water repellent, quaternized octadecyl methacrylate-2-diethyl-aminoethyl methacrylate as a mother resin and quaternized 1, 3-dioctadecyl-2, 7-dioxy-6, 8-di(2-hydroxyethyl)-1, 3, 6, 8-tetraazacyclodecane which increase the softening effect and the hydrostatic pressure blended with waxes and their emulsifier in various proportions to give water repellent PADWC. As the results of the measurement of water repellency, washable, tear strength and crease recovery to polyestercotton(P/C) blended fabrics treated with PADWC only or addition of textile finishing resin, the physical properties were increased. There was no significant lowering effect in water repellency when PADWC was treated the antistatic agent by the one-bath method, and the effect of water repellency by the adding the catalyst was studied. PADWC was confirmed as durable water repellent with the results of making little difference of water repellency as ${\pm}5$ point after and before washing.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.2
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• pp.13-20
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• 2013

In this study, two biodegradable polymer(PLA, PBS) emulsions were treated on agricultural packaging paper such as fruit bagging paper. Water-repellency, mechanical properties, and SEM image with thermal aging were measured on the emulsion treated fruit bagging paper. Biodegradable polymers(such as poly lactic acid, poly butylene succinate) emulsion treated fruit bagging paper had higher water-repellency and strength than other water-repellent(such as acrylic repellent, linseed oil and paraffin wax) treated fruit bagging paper. According to FE-SEM results of polymer emulsion coated fruit bagging paper, the colloidal particles of emulsion after thermal treatment (looks like being) were adhered to the fibers. Thus, using biodegradable polymer emulsion is expected to protect a fruit for a long time.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.494-504
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• 2016

Eucalyptus oils are widely used as spices, perfume industrial materials, food flavorings, and medicines. Several types of Eucalyptus oils also have insecticidal activity and as carminative. This study investigated the chemical composition, insecticidal (larvicidal and repellent) activity of E. urophylla oil against filarial mosquito Culex quinquefasciatus. E. urophylla oil was obtained from fresh leaves by water-steam distillation with oil yield 1.08%. E. urophylla oil in this study had no color (clear), has odor (typical eucalyptus), with specific gravity 0.941; refractive index 1.465; miscibility in 70% ethanol 1 : 3; and optical rotation (-) $5.83^{\circ}$. The major compounds of the oil were ${\alpha}$-pinene (11.73%), 1,8-cineole (49.86%), ${\beta}$-ocimene (6.25%), ${\gamma}$-terpinene (9.11%), and ${\alpha}$-terpinyl acetate (7.63%). The result showed the excellent insecticide activity against C. quinquefasciatus. The oil provided larvicidal activity with $LC_{50}$: 80.21 ppm and $LC_{90}$: 210.18 ppm, and repellent activity with $IC_{50}$: 0.82% and $IC_{90}$: 4.88%. The present study showed the effectiveness of E. urophylla as natural insecticide against C. quinquefasciatus, the mosquito vector of filariasis.

• Fashion & Textile Research Journal
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• v.22 no.1
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• pp.112-118
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• 2020

This paper examined the water repellency, water proofing and water vapor permeability of twelve types of woven fabrics for sports wear clothing. Their physical properties were compared and discussed with the fabric structural parameters and surface finishing effect. A water repellent property of 100% was obtained in the coated or laminated water repellent finished fabrics; in addition, cotton/nylon breathable composite fabrics treated with a laminated finishing and with low fabric density showed a 90% water repellency. Water proofing fabric above 6,000 mm H₂O hydraulic pressure was achieved by coated or laminated finishing; however, high density fabric or medium-level coated fabrics exhibited 100% water repellent and low water proofing characteristics. Superior water vapor permeability characteristics with good water repellency and proofing properties were achieved at the 2.5 layered low density and with 0.7 - 0.9 cover factor nylon fabrics treated with hydrophilic laminated finishing. The regression analysis for examining the effects of fabric structural parameters and surface finishing such as coating and laminating to the water vapor permeability exhibited a high determination coefficient of fabric structural parameters of 63.5%; in addition,, main factors among fabric structural parameters appeared to be cover factor and fabric thickness per weight. Coating and Laminating factors exhibited determination coefficient of water vapor permeability parameters of 36.5%.

• Macromolecular Research
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• v.17 no.9
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• pp.666-671
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• 2009

Water repellent elastomeric surfaces were fabricated successfully on SBS/MWNT nanocomposites films using the breath figure method and subsequent thermal treatment. The uniformly dispersed CNTs were found to play significant roles in tuning the size and ordering of the macroporous morphology at the nanocomposite surface as well as enhancing the mechanical properties of nanocomposites. In particular, the CNTs dispersed in a nanocomposite solution retarded the coarsening process of aqueous droplets during the breath figure process and decreased the pore size in the finally fabricated film. The water contact angle measurement showed that the double-scale structure comprised of self-organized macropores and surface the roughness induced by a thermal treatment produced a highly water-repellent nanocomposite surface.

• Textile Coloration and Finishing
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• v.17 no.6 s.85
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• pp.27-35
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• 2005

Conventional pad- dry-cure(thermo-fixation) process usually produces functional performance on both sides of a fabric. UV curing technique was applied to impart water- and oil-repellent finish effective only on the face of a PET knitted fabric. The preferential one-side coating, by virtue of the limited penetration of UV light, was achieved by W curing after padding of a fluorocarbon agent without special coating or printing equipments. The difference in the functional property of face and back sides was examined by measuring water and oil repellency at each side of the treated fabric. The influence of pre/post-irradiation dose and agent concentration on the performance of the finished fabrics were investigated. While increase in both resin concentration and post-irradiation did not have significant effect on the finish, UV pre-irradiation of PET fabrics caused remarkable influence presumably due to appropriate surface modification of PET fabrics required for facile wetting of the resin. The dimensional stability and color change of the UV cured fabrics measured by FAST and reflectance spectrophotometry showed significantly decreased color difference and increased percent extension compared with the samples pre-irradiated without agent application.

• Textile Coloration and Finishing
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• v.30 no.4
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• pp.275-287
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• 2018

In recent years, research on the development of eco-friendly synthetic suede based on water-dispersed polyurethane resin and non-fluorine water repellent has been conducted. Synthetic suede has a problem that the fastness to dyeing is greatly lowered after the water-repellent processing at a high temperature of $160^{\circ}C$ because the polyester is dyed with a disperse dye. Therefore, in this study, silica was added to water-dispersed polyurethane resin to improve dye fastness. To distribute the $PUD-SiO_2$ mixture evenly in the water-dispersed polyurethane resin, sufficient stirring was done for a period of time. When the $PUD-SiO_2$ mixture(PUD 1-5%) is applied to the substrate, it is confirmed through SEM that the mixture is uniformly applied without particle condensation. The results showed that silica with a diameter of 4~12nm and BET of $200{\sim}380g/m^2$ had the ability to improve dispersibility and fastness.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.97-104
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• 2023

In this paper, we propose a harmful bird repellent system using directional speakers. Existing sound systems for the extermination of harmful birds have the disadvantage of reducing effectiveness due to the learning effect of birds due to problems caused by noise pollution and monotonous sounds. In this paper, directional speakers are used to minimize surrounding noise. In addition, the up-down and left-right angles of the speaker driving device were freely adjusted to maximize usability. Additionally, the problem of performance degradation due to learning effects was solved by using various scanning patterns. In the future, we plan to develop a platform capable of central control by applying remote control functions and a deep learning model that can recognize bird species.

• Korean journal of applied entomology
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• v.60 no.3
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• pp.315-322
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• 2021

This study investigated the acaricidal and repellent activities of various plant extracts and Cnidium officinale-derived materials against Haemaphysalis longicornis. Among the 24 methanolic plant extracts, C. officinale showed the highest acaricidal activity (93.3%) against H. longicornis. Platycodon grandiflorus, Phytolacca americana, Magnolia denudata, Houttuynia cordata, C. officinale, and Pueraria montana showed significant differences in their repellent activity. Consequently, the activity of solvent-fractionated materials and the derived material of the C. officinale, was investigated and a 90% acaricidal effect was observed three days after hexane fraction treatment, indicating that the repellent response was statistically significant. Butylidenephthalide, which is a C. officinale-derived compound, showed 90% acaricidal activity seven days after treatment. Additionally, all H. longicornis moved to the untreated area in the t-tube olfactometer experiment, confirming the repellent activity of butylidenephthalide. Therefore, the results of this study suggest the use of C. officinale crude extract and butylidenephthalide as potent acaricidals and repellents against H. longicornis, respectively.

• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.31-39
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• 2021

The aim of this paper is to improve durability of cement paste by imparting hydrophobicity to the surface and sphere of cement-based materials. A cement paste mixed with a silane/siloxane-based water repellent, and the initial hydration performance, flow performance, and age-specific compressive strength were measured. In addition, the water contact angle, SEM, and XRD before and after surface polishing were measured. When 0.5% of the silane/siloxane-based water repellent was mixed into the cement paste, the compressive strength increased, but the compressive strength decreased as the mixing amount increased by 1.5% and 3.0%. When a silane/siloxane water repellent was incorporated into the cement paste, the hydrophilicity was improved and the contact angle was increased due to hydrophobicity. In addition, the contact angle after surface polishing was found to be larger than the contact angle before surface polishing.