TiO_2-x 산화물 박막공정을 이용한 유해자외선차단 투명유연소재개발

김극태,Kim, Geug Tae 한국결정성장학회 2019 한국결정성장학회지 Vol.29 No.3

본 연구에서는 $TiO_{2-x}$ 산화물 박막공정을 이용한 유해 자외선차단 투명 유연 소재를 개발하고자한다. 자외선 차단 특성: 자외선 파장대의 315 nm 차단율이 95 % 이상이면서, 자외선차단특성을 갖으면서 투명성을 높인 가시광선 투과율 78 % 이상(550 nm에서 전광투과율)의 시료를 만드는 공정기술을 개발하고자 하였다. 본 연구 결과로 고성능 자외선차단 박막의 유연 소자 공정조건을 확립하고, 이질성 특성의 투명 유연 소자의 혼합형 설계와 시장 요구에 다양하게 대응이 가능한 복합 증착 기술 정립, 롤투롤(roll-to-roll) 연속 공정의 실현 및 장비, 공정 국산화 기술 확립으로써 관련 산업으로의 기술 파급 효과가 클 것으로 사료된다. In this study, the development of transparent UV blocking material using $TiO_{2-x}$ oxide thin film process was developed. A process technology is related to a process technology for making a sample with ultraviolet-shielding property of visible light transmittance of 78 % or more (total light transmittance at 550 nm) and of a UV cut-off characteristic of more than 95 % at 315 nm in ultraviolet wavelength band. In this study, it is possible to establish a flexible device process condition of high performance ultraviolet (UV) shielding thin film, to design mixed type of transparent flexible device with heterogeneous characteristics and to formulate composite deposition technology, according to various market demands. Establishment of actual roll-to-roll continuous process and equipment and process technology will affect related industries greatly.

Effects of Aspect Ratio on Diffusive-Convection During Physical Vapor Transport of Hg₂Cl₂ with Impurity of NO

김극태,Kim, Geug-Tae The Korean Society of Industrial and Engineering C 2015 공업화학 Vol.26 No.6

본 연구에서는 $Hg_2Cl_2-NO$의 물리적 승화법 공정에서의 확산-대류에 미치는 에스펙트 비율(길이/폭)의 영향에 대한 것이다. 원료물질 영역과 결정영역에서의 온도 차 20 K, 벽에서의 선형 온도분포를 가진 계에서, 대류의 영향 때문에, 총몰플럭스와 상호계면에서의 비균일성에 관하여서는, 에스펙트 비율이 2인 경우가 비율이 5인 경우보다 상당히 크다. 지상중력 하에서의 최고 총몰플럭스는 지상중력의 0.1 상태에 비하여 대략 2배 정도 크다. 에스펙트 비율을 2에서 5로 증가시켰을 때, 확산-대류형이 대류형으로 전이되며, 또한 확산의 강도도 확산-대류형의 강도를 지배하게 된다. This study investigates the effects of aspect ratio (transport length-to-width) on diffusive-convection for physical vapor transport processes of $Hg_2Cl_2-NO$ system. For a system with the temperature difference of 20 K between an interface at the source material region and growing crystal interface, the linear temperature profiles at walls, the total molar fluxes at Ar = 2 are much greater than Ar = 5 as well as the corresponding nonuniformities in interfacial distributions due to the effect of convection. The maximum total molar flux at the gravitational acceleration of 1 $g_0$ is greater twice than at the level of 0.1 $g_0$, where g0 denotes the gravitational acceleration on earth. With increasing aspect ratio from 2 to 5, a diffusive-convection mode is transited into the diffusion mode, and then the strength of diffusion is predominant over the strength of diffusive-convection.

염화제일수은과 일산화질소의 물리적 승화법 공정에서의 확산-대류에 미치는에스펙트 비율의 영향

김극태 ( Geug Tae Kim ) 한국공업화학회 2015 공업화학 Vol.26 No.6

본 연구에서는 Hg2Cl2-NO의 물리적 승화법 공정에서의 확산-대류에 미치는 에스펙트 비율(길이/폭)의 영향에 대한 것이다. 원료물질 영역과 결정영역에서의 온도 차 20 K, 벽에서의 선형 온도분포를 가진 계에서, 대류의 영향 때문에, 총몰플럭스와 상호계면에서의 비균일성에 관하여서는, 에스펙트 비율이 2인 경우가 비율이 5인 경우보다 상당히 크다. 지상중력 하에서의 최고 총몰플럭스는 지상중력의 0.1 상태에 비하여 대략 2배 정도 크다. 에스펙트 비율을 2에서5로 증가시켰을 때, 확산-대류형이 대류형으로 전이되며, 또한 확산의 강도도 확산-대류형의 강도를 지배하게 된다. This study investigates the effects of aspect ratio (transport length-to-width) on diffusive-convection for physical vapor transport processes of Hg2Cl2-NO system. For a system with the temperature difference of 20 K between an interface at the source material region and growing crystal interface, the linear temperature profiles at walls, the total molar fluxes at Ar = 2 are much greater than Ar = 5 as well as the corresponding nonuniformities in interfacial distributions due to the effect of convection. The maximum total molar flux at the gravitational acceleration of 1 g0 is greater twice than at the level of 0.1 g0, where g0 denotes the gravitational acceleration on earth. With increasing aspect ratio from 2 to 5, a diffusive-convection mode is transited into the diffusion mode, and then the strength of diffusion is predominant over the strength of diffusive-convection.

지상 및 미소중력 환경에서 물리적 승화법 공정에 미치는 불순물의 영향 분석: 염화제일수은에 대한 응용성

김극태 ( Geug Tae Kim ),권무현 ( Moo Hyun Kwon ) 한국공업화학회 2016 공업화학 Vol.27 No.3

본 연구에서는 지상 및 미소중력환경하에서 물리적 승화법 공정에서의 확산-대류유동에 미치는 불순물의 영향을 이론적으로 Hg2Cl2-I2 시스템에 적용하여 규명하는 것이다. 이론적 해석은 증기상에서 확산-대류 흐름, 열 및 물질전달을 속도 벡터 흐름, 유선, 온도, 농도 분포를 통하여 제시된다. 결정 영역에서의 전체 몰플럭스는 중력가속도와 성분 I2, 불순물에 상당히 민감하게 반응한다. 성분 I2을 증가시켰을 때, 농도 대류효과는 확산-대류 유동흐름을 안정화시키는 경향이 있다. 지상중력가속도의 0.001환경에서는 유동흐름은 1차원포물선의 흐름 구조를 나타내며, 확산지배형태를 보여주고 있다. 10(-3)지상중력가속도 이하에서는 대류 영향은 무시할 수 있다. In this study, impurity effects on diffusive-convection flow fields by physical vapor transport under terrestrial and microgravity conditions were numerically analyzed for the mixture of Hg2Cl2-I2 system. The numerical analysis provides the essence of diffusive-convection flow as well as heat and mass transfer in the vapor phase during the physical vapor transport through velocity vector flow fields, streamlines, temperature, and concentration profiles. The total molar fluxes at the crystal regions were found to be much more sensitive to both the gravitational acceleration and the partial pressure of component I2 as an impurity. Our results showed that the solutal effect tended to stabilize the diffusive-convection flow with increasing the partial pressure of component I2. Under microgravity conditions below 10-3g0, the flow fields showed a one-dimensional parabolic flow structure indicating a diffusion-dominant mode. In other words, at the gravitational levels less than 10(-3)g0, the effects of convection would be negligible.

바텀애쉬를 이용한 흡음 내장재 개발에 관한 연구

전현철,김극태,Jun, Hyun Chul,Kim, Geug Tae 한국결정성장학회 2017 韓國結晶成長學會誌 Vol.27 No.3

본 연구에서는 국내 화력발전소에서 발생되는 바텀애쉬를 이용하여 질석 성형물을 제작하였으며, 이를 이용하여 흡음 건자재 제조를 위한 흡음성, 최고 휨파괴하중에 대하여 고찰하였다. 이러한 바텀애쉬와 질석의 성형물 제조를 위하여, 마이크로웨이브 건조방식의 공정를 사용하였다. 또한, 바텀애쉬의 볼밀링작업을 통하여 얻어진 $65{\mu}m$ 정도의 크기의 균일한 분말이 사용되었다. 5, 10 wt%의 바텀애쉬와 질석의 성형물을 제조하여, 최고 휨파괴하중 특성이 분석 되었다. 이러한 실험 결과들은 바텀애쉬의 재활용 기술에 필요한 기초적인 데이터를 제공한다. In this study, we prepared the board of vermiculite materials utilizing coal bottom ash from the Western thermal power stations in Korea and obtained experimental data in applications for building interior materials with the characteristics of sound absorption. To produce the mixture materials of vermiculite and coal bottom ash, we used a microwave drying process. In addition, a ball milling process was used to produce particles of coal bottom ash with a uniform size of $65{\mu}m$. When the board made from mixture materials of vermiculite and coal bottom ash were produced with bottom ash sulfur concentrations of 5, 10 wt%, maximum bending loads were analyzed. These experimental results would contribute much to fundamental data essential to the recycling technology of coal bottom ash.

0.5 mm 이내의 두께를 갖는 4층 구조의 스마트 윈도우에 적용되는 전기변색 ECD(electro-chromic device) 필름 제조 및 특성

김남일,김극태,Nam Il Kim,Geug Tae Kim 한국결정성장학회 2024 한국결정성장학회지 Vol.34 No.1

Using electrochromic devices (ECD), smart window films that can change the colors from tinted state into transparent state by applying an external voltage were manufactured. Polyethylene terephthalate (PET) film was used as a substrate instead of conventional glass, and ECD modules having a total thickness of about 50 ㎛ were manufactured by sequentially introducing an ITO/Ag/ITO electrode layer, a WO3/TIC2 organic discoloration layer, and a Nafion fluorine electrolyte layer. Through a series of sputtering, bar coating, and thermal compression processes, a large scale smart window with a horizontal and vertical length of more than 80 mm was manufactured. When DC 3.5 V was applied, the transmittance decreased from 54 % to 24 % and moreover the color change could be confirmed even with the naked eye. Reversible color change capability at low external voltage implies that external sunlight can be selectively blocked which is effective in terms of energy saving.

비전통자원개발에 따른 수처리 최신 기술

박정규 ( Jung Kyu Park ),김극태 ( Geug Tae Kim ),정건용 ( Kun Yong Chung ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.2

최근 수평시추, 수압파쇄 등의 기술발전에 따라 셰일가스, 셰일오일, 석탄층 메탄가스 등 비전통자원개발이 활성화되었다. 이러한 기술발전으로 생산성이 향상되었지만, 화학약품이 포함된 수압파쇄 유체와 오일, 가스와 고농도의 염과 방사성 물질을 함유하는 생산수가 가스 생산중 발생하게 된다. 이같이 생성된 대량의 폐수에 따른 부정적인 환경적 요인은 비전통자원개발에 주요 장애요소로 급격히 대두되고 있다. 본 연구에서는 비전통자원개발에 따른 회수수와 생산수의 처리방법에 대한 융합적인 토대를 제시하고, 새롭게 떠오르는 다양한 수처리 기술을 총설하고자 한다. 비전통자원개발 현장에 적용 가능한 기본적인 분리공정인 막분리, 증발, 결정화, 탈염공정 기술을 소개하고 또한 대량의 수자원을 사용하는 비전통자원개발의 특성상 물의 재이용 및 재활용이 가능한 기술을 소개하고자 한다. Development of unconventional natural resources such as shale gas, shale oil and coal bed methane, has been activated and improved the productivity due to the recent technology advance in horizontal drilling and hydraulic fracturing. However, the flow back water mixed with chemical additives, and the brine water containing oil, gas, high levels of salts and radioactive metals is produced during the gas production. Potential negative environmental impact due to large volumes of the produced wastewater is increasingly seen as the major obstacles to the unconventional natural resource development. In this study an integrated framework for the flow back and brine water treatment is proposed, and we reviewed the upcoming state of the art technology in water treatment. Basic separation processes which include not only membrane, evaporation, crystallization and desalination processes, but the potential water reuse and recycling techniques can be applied for the unconventional natural resource industry.

혼합폐플라스틱 열분해 왁스오일의 고급화 연구

이경환(Lee, Kyong-Hwan),남기윤(Nam, Ki-Yun),송광섭(Song, Kwang-Sup),김극태(Kim, Geug-Tae),최정길(Choi, Jeong-Gil) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.11

Upgrading of pyrolysis wax oil has been conducted in a continuous fixed bed reactor at 450?C, 1hour, LHSV 3.5/h. The catalytic degradation using HZSM-5 catalyst are compared with the thermal degradation and also was studied with a function of experimental variables. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around 300?C to 550?C, which has considerably higher boiling point distribution than that of commercial diesel. The product characteristic from thermal degradation shows a similar trend with that of raw pyrolysis wax oil. This means the thermal degradation of pyrolysis wax oil at high degradation temperature is not sufficiently occurred. On the other hand, the catalytic degradation using HZSM-5 catalyst relative to the thermal degradation shows the high conversion of pyrolysis wax oil to light hydrocarbons. This liquid product shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Also, in the catalytic degradation the experimental variable such as catalyst amount and reaction temperature was studied.

산화알루미늄 증착 필름의 XPS 특성

김정식,권무현,최정길,양장수,김극태 한국공업화학회 2000 응용화학 Vol.4 No.1

The aluminum oxide thin films have been deposited on PET substrate film using r.f. magnetron sputtering from an aluminum oxide magnetron target and argon plasma. The electronic structures of aluminum oxides have been examined using XPS. The XPS spectrum for the aluminum oxide showed the presence of a well resolved Al 2p spectral line at 74.3±0.2 eV (FWHM=∼2.1). Depending on synthetic conditions, the binding energies of A1 2p and O 1s for samples used in the current study are same, or very similar. The average ratio of Oo/Al for all the aluminum oxides was 2.8, indicating that the deviation from the stoichiometric atomic ratio of 1.5 in Al₂O₃ is accounted for by the incomplete oxidation. Given the reference energies of 531.0 eV for O 1s and 72.7 eV for Al 2p, the Al 2p peak tended to shift to higher energies while the O 1s peak shifted to lower energies. During the synthesis of aluminum oxide thin films, there was a correlation between the preparative conditions and the relative intensity for the Al 2p and O 1s peak. The peak intensities of Al 2p and O 1s were increased with increasing the sputtering power as well as the sputtering time. These results indicate that there was a linear relationship between the peak intensities of Al 2p and O 1s and the sputtering power.

옻칠액의 유변학에 관한 연구

김정식,권무현,최정길,양장수,김극태,서덕종 한국공업화학회 2000 응용화학 Vol.4 No.1

Rheology of three natural lacquers, Korea, China and Japan has been studied for the storage(G' ) and loss(G") Young's modulus shear velocity of viscosity. The storage(G' ) and loss(G") Young's modulus of all lacquers are increased with increasing a frequency. The slope of storage(G') and loss(G") Young's modulus for the Japan were greater than the Korea and the Chinaby by a factor of 3. The viscosity is non-linearly decreased with increasing the shear velocity in the range of 0.01∼30, which indicates non-Nowton fluid with the shear thinning. The behaviors of shear thinning for the Korea and the China appear clearly in comparison with the Japan. This might be intimately related to the degree of purity of the laquer. The Japan has a higher purity than the Korea and the China.