• 통합자연과학논문집
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• 제6권4호
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• pp.215-219
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• 2013

In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that a well prepared APS-SAM on a glass surface treated with water vapor/Ar plasma is very useful for uniform coating of FeCl3 and DUDO mixed oxidant solution, regardless of HF treatment. On the other hand, a bare glass surface without APS-SAM but treated with HF and water vapor/Ar plasma generally led to a very poor oxidant film. As a result, PEDOT films vapor phase-polymerized on APS-SAM surfaces are far superior to those on bare glass surfaces in the quality and electrical characteristics aspects.

• 한국정밀공학회지
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• 제27권7호
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• pp.87-93
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• 2010

This paper presents an evaluation of efficiency on glass precision machining by using abrasive water-jet machine. In this study, problems of conventional water-jet machining are examined experimentally and are analysized numerically. Especially, the reason of whitening on the machined surface of biochip glass is determined. It is found that the mass flow rate of abrasive input and transverse speed of water-jet are key parameters to control the direct machining of micro hole and channel on a glass substrate. Based on results of experimental analysis, possibility of direct fabrication of micro holes and channels on a glass substrate is successfully confirmed.

• 마이크로전자및패키징학회지
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• 제9권2호
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• pp.19-25
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• 2002

저온소결기판을 위하여 green sheet를 제조하기 위한 조성으로 $Li_2$O.MgO. $MgF_2$.$SiO_2$.$B_2O_3$를 기초 조성으로 선정하였다. 조합 후 용융하여 만들어진 모유리는 열분석을 통하여 최적 핵형성 온도와 최고 결정성장 온도를 도출하였으며 핵형성 온도는 전이온도와 같은 $490^{\circ}C$로 선정하였다. 결정화 유리를 제조하기 위하여 두 단계의 열처리를 실시하였으며 , 생성된 결정상은 Lithium fluorhectorite와 Lithium boron fluorphlogopite결정상 이었다. 계속적으로 제조된 결정화 유리는 water swelling 현상을 이용하여 분말화를 실시하였으며 평균 입도크기는 2.574 $\mu\textrm{m}$이었다. glass ceramics 분말은 물에 넣으면 반응하여 팽창하는 것과 함께 끈적끈적한 sol이 생성되는 현상을 이용하여 green sheet 제조를 위한 slurry를 제조하였다. Tape casting을 위한 slurry의 결정화 유리 분말 대비 용매의 최적 비율은 100:18이었고, 슬러리의 점도는 11,000~14,000cps 이었다. KCl 1 M용액 10min담지 시편에 대해서는 $900^{\circ}C$에서, 20 min담지 시편에 대해서는 $800^{\circ}C$에서 각각 치밀한 소결성을 나타내었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1424-1429
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• 2004

Distillation is one of many processes that can be used for the purification of water. It requires an energy input such as heat and solar radiation is a possible source of energy. In this process, water is evaporated, thus separating water vapor from the solute. The vapor is then condensed to pure water. The temperature of the water, the cavity of the enclosure and the surface of the glass was measured everyday. Fifteen points were chosen for the temperature measure using a thermocouple. The inner wall and the bottom of each still was painted black for good absorption of heat. The enforced glass was used for the cover for the entering of solar energy. The size of all of the water baths was the same, but the glass of the rectangular form had a tilted angle. In the case of fine or general weather, the volume of condensed water produced by $45^{\circ}$ and $60^{\circ}$ is very irregular compared to that of $15^{\circ}$ and $30^{\circ}$, In case of a rainy day, the occurrence of the volume of condensed water was similar to that of $15^{\circ}$ and $30^{\circ}$, but the volume of condensed water produced by $30^{\circ}$ was the highest.

• 마이크로전자및패키징학회지
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• 제24권3호
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• pp.13-18
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• 2017

물유리는 기존의 silicon alkoxide보다 훨씬 단가가 저렴하여 상업화에 유리하다는 장점을 나타낸다. 물유리 기반 실리카 에어로겔의 제조에서 산 촉매에 의한 중합 과정이 최종 미세 기공구조 특성에 상당한 영향을 끼치는데, 본 연구에서는 이러한 산 촉매의 종류와 양에 대한 물유리 기반 실리카 에어로겔의 비표면적, 기공 크기 분포 등 각 경우에 해당하는 물성 및 그에 따른 차이를 연구하였다. 최종 생성물의 물성을 통해 물유리 기반 실리카 에어로겔은 중합 반응에 관여하는 산 촉매의 종류와 농도, 몰수에 의해 영향을 받고, 특히 산 촉매의 몰수에 의한 영향이 몰 농도에 의한 영향보다 크게 작용함을 확인하였다. 기존 방식으로 4M 염산 촉매를 첨가할 경우 비표면적이 $394m^2/g$, 기공의 부피가 2.20 cc/g, 평균 기공 지름이 22.3 nm이며 기공률이 92.53%인 실리카 에어로겔을 합성할 수 있었다. 반면 4M의 황산 촉매를 적정량의 몰수인 73 mmol로 투입하여 최종 물유리 기반 실리카 에어로겔을 제조할 경우 비표면적은 $516m^2/g$, 기공의 부피는 3.10 cc/g, 평균 기공 지름은 24.1 nm, 기공률은 96.1%로, 기존의 산 촉매를 투입하여 만든 물유리 기반 실리카 에어로겔보다 전반적으로 기공구조의 특성이 향상됨을 확인하였다.

• The Korean Journal of Ceramics
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• 제6권1호
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• pp.37-42
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• 2000

To reduce shrinkage and the possibility of fracture during ambient pressure drying, it is of great importance to increase the strength and stiffness of the wet gels. In this paper is presented the strengthening and stiffening of wet silica gels prepared from sodium silicate (water glass) as well as properties of the corresponding xerogels. By washing gels containing different initial silica contents in water solutions at elevated pH, a maximum in shear modulus of ~4 MPa was obtained. The maximum stiffness enabled xerogels with bulk density of 0.28g/$\textrm{cm}^3$ to be made regardless of silica content and washing conditions. However, by aging the wet gels in a solution providing fresh monomers to the gel network, a shear modulus of 20 MPa was obtained after 27h. By this method monolithic xerogels with a density down to ~0.2g/$\textrm{cm}^3$ was prepared. The results are compared to alkoxide based gels.

• 한국재료학회지
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• 제2권2호
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• pp.133-142
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• 1992

E-glass/Polyester 적층복합재료의 인공해수중에서의 인장특성을 알아보기 위해 PH를 각각 6.0, 8.2, 10.0으로 조절한 가운데 저 변형율 인장시험($1{\times}10^{-4}~1{\times}10^{-7}sec^{-1}$)을 행하였다. 대기와 인공해수중에서 인장하중을 받은 시험된 복합재료는 strain rate가 감소할수록 인장특성이 저하되며 $1{\times}10^{-7}sec^{-1}$의 strain rate에서 약간의 강성저하가 관찰되었다. 한편 인공해수중의 인장특성은 PH값에 따라 약간의 변화를 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.18-21
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• 1995

In this study, crystallization, water swelling and dielectric properties of Li$_2$O-MgO-MgF$_2$-SiO$_2$System glass ceramics were investigated. Base glass melted at 1450$^{\circ}C$ and crystallized through heat treatment. The optimum heat treatment schedule was 460$^{\circ}C$ for nucleation and 640$^{\circ}C$, 1100$^{\circ}C$ for crystallization. The Principle crystalline phase was lithium fluorhectorite. Lithium fluorhectorite was the crystal phase which it was influenced water swelling. Samples progressed 2 minutes later they have rapid hydration at forced water swelling condition. Also value of dielectric constants have approximately 10 at 100kHz.

• 한국진공학회지
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• 제9권3호
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• pp.279-284
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• 2000

본 연구는 옥외용 epoxy/glass fiber의 열화과정을 분석하기 위하여 FRP 적층판을 고온과 수에 노출시켰다. 열화과정은 접촉각, 표면전위감쇠, 표면저항률의 비교에 의해 평가하였다. 젖음성의 변화는 열처리 시료에서 $200^{\circ}C$까지 접촉각이 증가하였지만 수분처리 시료는 감소하였다. 표면전위감쇠 특성은 수분처리 시료에서는 감소하지만, 열처리 시료는 미 처리와 비교해서 증가하였다. 또한, 표면저항률은 접촉각의 변화와 같은 경향을 보이고 있다.

• Computers and Concrete
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• 제24권2호
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• pp.151-158
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• 2019

The sustainable development principle of replacing natural resources with renewable material is an important research topic. In this study, waste LCD (liquid crystal display) glass powder was used to replace cement (0%, 10%, 20% and 30%) through a volumetric method using three water-binder ratios (0.47, 0.59, and 0.71) to make cement mortar. The compressive strength was tested at the ages of 7, 28, 56 and 91 days. The test results show that the compressive strength increases with age but decreases as the water-binder ratio increases. The compressive strength slightly decreases with an increase in the replacement of LCD glass powder at a curing age of 7 days. However, at a curing age of 91 days, the compressive strength is slightly greater than that for the control group (glass powder is 0%). When the water-binder ratios are 0.47, 0.59 and 0.71, the compressive strength of the various replacements increases by 1.38-1.61 times, 1.56-1.80 times and 1.45-2.20 times, respectively, during the aging process from day 7 to day 91. Furthermore, a prediction model of the compressive strength of a cement mortar with waste LCD glass powder was deduced in this study. According to the comparison between the prediction analysis values and test results, the MAPE (mean absolute percentage error) values of the compressive strength are between 2.79% and 5.29%, and less than 10%. Thus, the analytical model established in this study has a good forecasting accuracy. Therefore, the proposed model can be used as a reliable tool for assessing the design strength of cement mortar from early age test results.