• 대한가정학회지
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• 제23권1호
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• pp.11-17
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• 1985

This paper aims to examine the variety of the absorption of cotton, T/C and hemp fabrics seperately seperaterly sized by rice, wheat, potato, corn flour and pp.V.A.. Experimental variables occurring in the concentration of sizing agents, the water content of unsized fabrics and an iron temperature show the following results, 1. When fabrics sized, the rate of absorption increases according to the order of rice, corn, pp.V.A., potato, wheat flour for cotton fabrics, of rice, corn, pp.V.A., wheat, potato flour for hemp fabrics and of the rice, pp.V.A., potato, corn, wheat flour for T/C fabrics : rice flour shows an absorption rate highest among all the others mentioned above. 2. To a certain extent, the stronger the concentration of sizing agents, the higher the rate of absorption. 3. The higher fabrics density, the higher absorption rate. 4. The structure and hydrophilic property of the sized fabrics affect the rate of absorption. 5. The fabrics with water content of 20% before sizing it shows the rate of absorption highest. 6. An iron temperature after sizing fabrics shows the rate of absorption highest at the properest at the properest one : $180^{\circ}C$ for cotton, $150^{\circ}C$ for T/C and $200^{\circ}C$ for hemp fabrics.

• 한국수소및신에너지학회논문집
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• 제23권1호
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• pp.19-25
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• 2012

The efficiency and life time of the Proton Exchange Membrane fuel cell (PEMFC) system is critically affected by incoming gas with humidity which should be maintained properly at normal operating conditions. Typically, incoming gas of automotive fuel cell is humidified by external humidifier but the characteristics of device is rarely reported. In this study, characteristics of water transfer in the membrane humidifiers have been experimentally investigated for flow rates of gas and for different flow arrangement under steady state condition. At first, capability of mass transfer through the membrane is examined at constant temperature. Then, the temperature distribution effect on the capability of mass transfer is tested over various inlet conditions. In summary, this research presents the mass transfer capability of hydrophilic membrane over various operating conditions.

• Carbon letters
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• 제14권4호
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• pp.247-250
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• 2013

In this study, we present a facile method of fabricating graphene oxide (GO) films on the surface of polyimide (PI) via layer-by-layer (LBL) assembly of charged GO. The positively charged amino-phenyl functionalized GO (APGO) is alternatively complexed with the negatively charged GO through an electrostatic LBL assembly process. Furthermore, we investigated the water vapor transmission rate and oxygen transmission rate of the prepared (reduced GO $[rGO]/rAPGO)_{10}$ deposited PI film (rGO/rAPGO/PI) and pure PI film. The water vapor transmission rate of the GO and APGO-coated PI composite film was increased due to the intrinsically hydrophilic property of the charged composite films. However, the oxygen transmission rate was decreased from 220 to 78 $cm^3/m^2{\cdot}day{\cdot}atm$, due to the barrier effect of the graphene films on the PI surface. Since the proposed method allows for large-scale production of graphene films, it is considered to have potential for utilization in various applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.874-877
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• 2004

We carried out this subject to observe electrochemical properties of 1,2-dioleoyl-sn- glycero-3-phosphocholine(DOPC) mixed with fatty acid containing azobenzene group by using cyclic voltammetry with a three-electrode system, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode in $NaClO_4$ solution. We investigated the photoisomerization and electrochemical property of the organic ultra thin film of fatty acid containing azobenzene was prepared on the hydrophilic ITO(idium tin oxide) glass plate by LB method. As a result, the absorption spectra of BASH and DOPC of mixture LB films was induced to photoisomerization by alternating irradiation of ultraviolet and visible light. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150 and 200 mV/s. As a results, LB films of BASH-DMPC appeared reversible process caused by the reduction-oxidation current from the cyclic voltammogram.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.36-38
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• 2005

This study is about how to lower the driving voltage that enables to move the micro droplet by the EWOD (Electro Wetting On Dielectric) mechanism. EWOD is well known that it is used ${\mu}-TAS$ digital micro fluidics system. As the device which is fabricated with dielectric layer between electrode and micro droplet is applied voltage, the hydrophobic surface is changed into the hydrophilic surface by electrical property. Therefore, EWOD induces the movement of micro droplet with reducing contact angle of micro droplet. The driving voltage was depended on the dielectric constant of dielectric layer, thus it can be reduced by increase of dielectric constant. Typically, very high voltage ($100V{\sim}$) is used to move the micro droplet. In previous study, we used $Ta_{2}O_{5}$ as the dielectric layer and driving voltage was 23V that reduced 24 percent compared with $SiO_2$. In this study, we used $BZN(Bi_{2}O_{3}ZnO-Nb_{2}O_{5})$ layer which had high dielectric constant. It was operated the just 12V. And micro droplet was moved within Is on 15V. It was reduced the voltage until 35 percents compare with $Ta_{2}O_{5}$ and 50 percents compare with $SiO_2$. The movement of micro droplet within 1s was achieved with BZN (ferroelectrics)just on 15V.

• 한국전기전자재료학회논문지
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• 제29권4호
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• pp.215-217
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• 2016

For the improvement of the anti-pollution properties of porcelain electrical insulators, in this study, we have applied the functional film to the surface of insulator. The functional films were coated on the ceramic substrates which components were like the porcelain electrical insulator. The coating material was applied to ceramic substrate by spray coating method and then the film was cured at around $300^{\circ}C$ for 10 minutes with different gas ambient, such as $O_2$, $N_2$, and only vacuum. We have measured the contact angle of the coated surface, and obtained the lowest angle ($8.9^{\circ}$) and a strong hydrophilic property at vacuum condition. The anti-pollution properties were measured, revealing that as the contact angle decreased, the anti-pollution properties improved. The mechanical hardness and adhesion were both excellent regardless of the annealing ambient.

• 한국의류산업학회지
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• 제22권1호
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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%.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.121-121
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• 2011

Graphene formed by chemical vapor deposition was exposed to the various plasmas of Ar, O2, N2, and H2 to examine its effects on the bonding properties of graphene to metal. Upon the Ar plasma exposure of patterned graphene, the subsequently deposited metal electrodes remained intact, enabling successful fabrication of field effect transistor (FET) arrays. The effects of enhancing adhesion between graphene and metals were more evident from O2 plasmas than Ar, N2, and H2 plasmas, suggesting that chemical reaction of O radicals induces hydrophilic property of graphene more effectively than chemical reaction of H and N radicals and physical bombardment of Ar ions. From the electrical measurements (drain current vs. gate voltage) of field effect transistors before and after Ar plasma exposure, it was confirmed that the plasma treatment is very effective in controlling bonding properties of graphene to metals accurately without requiring buffer layers.

• 대한화학회지
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• 제62권2호
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• pp.113-117
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• 2018

The basic hydrogel lens with addition of N,N-dimethylacrylamide (DMA) and N-methyl-N-vinylacetamide (NMV) were manufactured. The optical and physical characteristics of ophthalmic lens were evaluated by measuring water content, oxygen permeability (Dk), refractive index and optical transmittance. The water content & oxygen permeability (Dk) of sample containing Ref., DMA group and NMV group was in the average of 34.48%, 35.54~49.19% & $13.003{\sim}18.468{\times}10^{-11}(cm^2/sec)$($mlO_2/ml{\times}mmHg$) and 36.28~44.95% & $12.270{\sim}16.883{\times}10^{-11}(cm^2/sec)$ ($mlO_2/ml{\times}mmHg$), respectively. And also, refractive index of the sample containing Ref., DMA group and NMV group was in the average of 1.4350, 1.4330~1.4131 and 1.4335~1.4195, respectively. Standard hydrogel monomer containing DMA and NMV was expected to be used usefully as a material for fabricating hydrophilic functional ophthalmic lens.

• 한국재료학회지
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• 제18권8호
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• pp.417-421
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• 2008

$Al_2O_3$ sol with long-term stability was prepared by mechanical milling. Thin films were evaluated and created for use as coating materials. The particle size of the manufactured sol was 98 nm when 2 wt% of nitric acid was added. This indicates that the viscosity of the sol is 12 cps and that it has long-term stability. The thickness of the thin films, which varied from 100 nm to 500 nm, could be managed by adjusting the draw rate and the amount of an organic additive. A thin film heated to $500^{\circ}C$ indicated a hydrophilic property against water and excellent permeability against a visible ray.