용매저항성 폴리벤즈이미다졸 분리막의 제조 및 특성평가

정문기 ( Moon Ki Jeong ),남상용 ( Sang Yong Nam ) 한국공업화학회 2017 공업화학 Vol.28 No.4

최근 특정 용매에 대한 저항성이 있고 특정 분획분자량을 가지는 고분자 분리막을 통해 용매 또는 용질의 분리가 이루어지는 용매저항성 나노여과막에 대한 연구가 많이 이루어지고 있다. 이러한 분리막의 필수조건은 우수한 물성과 용매저항성을 가지는 것인데 현존하는 상업용 고분자 중 가장 내열성이 좋다고 알려진 폴리벤즈이미다졸은 고유의 용매저항성 역시 뛰어나지만 가교되었을 때 강한 유기용매에도 녹지 않는 특성을 가진다. 따라서 본 연구에서는 이러한 폴리벤즈이미다졸의 용매저항성을 이용한 나노여과막의 적용 가능성에 대하여 논의하고자 하였다. 분리막의 제조는 비용매유도상전이법을 통해 실시하였고 전계방출형 주사전자현미경을 통해 나노여과막으로서 적절한 복합막을 형성하는 것을 확인하였다. 또한, 가교유무에 따른 용매의 투과성능을 확인하였고 장시간 운전을 통하여 용매에 대한 내구성에 따른 안정성 또한 확인하였다. 투과도 실험은 물, 에탄올, 벤젠, N, N-dimethylacetamide (DMAc), n-methyl-2-pyrrolidone (NMP) 다섯 가지 용매에 의해 실시되었으며 각각의 초기 플럭스는 6500 L/m²h (Water, 2 bar), 720L/m²h (DMAc, 5 bar), 185 L/m²h (Benzene, 5 bar), 132 L/m²h (NMP, 5 bar), 65 L/m²h (Ethanol, 5 bar)를 나타내었고 분리막의 종류에 따라 2-5 bar의 압력을 적용하였다. Recently, solvent-resistant nanofiltration membranes have been studied for the separation of solvents or solutes using a molecular weight cut-off system of the polymer which is resistant to a specific solvent. Required conditions for these membranes must have are excellent physical properties and solvent resistance. Polybenzimidazole, which is known to be one of the most heat-resistant commercially available polymers, has an excellent inherent solvent resistance and it is even insoluble in stronger organic solvents when cross-linked. Therefore, in this study, the applicability of polybenzimidazole as a solvent resistant nanofiltration membrane was discussed. The membrane was fabricated using the non-solvent induced phase separation method and showed a suitable morphology as a nanofiltration membrane confirmed by field emission scanning electron microscopy. In addition, the permeance of the solvent in the presence or absence of cross-linking was investigated and the stability was also confirmed through long operation. The permeance test was carried out with five different solvents: water, ethanol, benzene, N, N-dimethylacetamide (DMAc) and n-methyl-2-pyrrolidone (NMP); each of the initial flux was 6500 L/m²h (water, 2 bar), 720 L/m²h (DMAc, 5 bar), 185 L/m²h (benzene, 5 bar), 132 L/m²h (NMP, 5 bar), 65 L/m²h (ethanol, 5 bar) and the pressure between 2 and 5 bar was applied depending on the type of membrane.

3D IC 제작에서의 다층적층 공정 개선을 위한 방법

정문기(Moon Ki Jeong),신운기(Woon Ki Shin),이현섭(Hyun Seop Lee),최성하(Sungha Choi),정해도(Hea Do Jeong) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.4

고선택성 폴리이미드 소재의 합성 및 분자동력학 연구를 통한 기체투과도의 비교

이정무,김득주,정문기,이명건,박치훈,남상용,Lee, Jung Moo,Kim, Deuk Ju,Jeong, Moon Ki,Lee, Myung Gun,Park, Chi Hoon,Nam, Sang Yong 한국막학회 2015 멤브레인 Vol.25 No.2

In this study, gas permeability of polyimide materials having a various amine group was measured and molecular dynamics was used to analyze the dynamic characteristics of the gas molecules in the polyimide by calculating the position and velocity of the gas molecules with change of the time. The gas permeability of polyimide membrane having substitution site which increase free volume in the polymer was increased. However, polyimide with rigid structure showed decreased gas permeability. As a result of analyzing the change in the gas permeation behavior using molecular dynamics simulations, we confirmed that the results show the same tendency with actual measurements of the gas permeability. 본 연구에서는 다양한 아민기를 가지는 폴리이미드 소재 및 분리막을 제조하여 그들의 구조의 변화에 따른 기체 투과도를 측정하였으며 동력학(Molecular dynamics; MD) 기술을 이용하여 해당 기체의 시간의 변화에 따른 위치와 속도를 계산하여, 기체분자의 동적 특성을 분석하는데 활용하였다. 투과도 측정결과 합성된 고분자 소재의 경우 고분자 내의 free volume을 증가시키는 치환기를 도입시켰을 경우 기체투과도가 증가되었으나 rigid한 구조가 도입된 폴리이미드는 투과도가 감소되는 경향을 확인하였다. 또한 분자동력학 시뮬레이션을 이용하여 기체투과거동 변화를 분석한 결과 실제 기체투과도 측정결과와 유사한 결과를 나타냄을 확인할 수 있었다.

로드셀을 이용한 요류검사기의 구현 및 평가

정도운 ( Do Un Jeong ),조성택 ( Seong Taek Cho ),남기곤 ( Ki Gon Nam ),정문기 ( Moon Kee Chung ),전계록 ( Gye Rok Jeon ) 한국센서학회 2004 센서학회지 Vol.13 No.6

N/A In this study, a uroflowmetry system was developed to detect a voiding symptom conveniently at home or hospital A implemented hardware was composed of mechanism and system circuit part, the software was developed to process uroflow data, graph display, extraction of parameter, and evaluation of congregate rate so as to analysis obtaining uroflow data. The following experiment was performed to evaluate an ability of classification and fitness. The curve pattern of uroflow was classified into each symptom. Various parameters were calculated in the curve pattern of each uroflow as follows. The parameters are MFR, AFR, VOL, VT, and FT. A significant difference among parameters was examined by a statistical analysis for extracted parameters between normal and abnormal experimental group. The uroflow data with the various symptom was divided into normal and abnormal group using fuzzy classifier. The result of the fuzzy classification using MFR and AFRwas superior by 91.23 % than grouping evaluation including VOL.

피동적 유체기구의 유동 조절 특성에 관한 실험

서정식,송철화,조석,정문기,최영돈,Seo, Jeong-Sik,Song, Chul-Hwa,Cho, Seok,Chung, Moon-Ki,Choi, Young-Don 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.3

A model testing has been performed to investigate the flow characteristics of a vortex chamber, which plays a role of a flow switch and passively controls the discharge flow rate. This method of passive flow control is a matter of concern in the design of advanced nuclear reactor systems as an alternative to the active flow control to provide emergency water to the reactor core in case of postulated accidents like LOCA (Loss-Of-Coolant Accident). By changing the inflow direction in the vortex chamber and varying the flow resistance inside the chamber, the vortex chamber can control passively the injection flowrate. Fundamental characteristics such as discharge flow rate and pressure drop of the vortex chamber are measured, and its parametric effects on the performance of the vortex chamber are also systematically investigated.

구리 CMP 후 버핑 공정을 이용한 연마 입자 제거

신운기,박선준,이현섭,정문기,이영균,이호준,김영민,조한철,주석배,정해도,Shin, Woon-Ki,Park, Sun-Joon,Lee, Hyun-Seop,Jeong, Moon-Ki,Lee, Young-Kyun,Lee, Ho-Jun,Kim, Young-Min,Cho, Han-Chul,Joo, Suk-Bae,Jeong, Hae-Do 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.1

Copper (Cu) had been attractive material due to its superior properties comparing to other metals such as aluminum or tungsten and considered as the best metal which can replace them as an interconnect metal in integrated circuits. CMP (Chemical Mechanical Polishing) technology enabled the production of excellent local and global planarization of microelectronic materials, which allow high resolution of photolithography process. Cu CMP is a complex removal process performed by chemical reaction and mechanical abrasion, which can make defects of its own such as a scratch, particle and dishing. The abrasive particles remain on the Cu surface, and become contaminations to make device yield and performance deteriorate. To remove the particle, buffing cleaning method used in post-CMP cleaning and buffing is the one of the most effective physical cleaning process. AE(Acoustic Emission) sensor was used to detect dynamic friction during the buffing process. When polishing is started, the sensor starts to be loaded and produces an electrical charge that is directly proportional to the applied force. Cleaning efficiency of Cu surface were measured by FE-SEM and AFM during the buffing process. The experimental result showed that particles removed with buffing process, it is possible to detect the particle removal efficiency through obtained signal by the AE sensor.

이온교환막 공정 및 응용 연구동향

김득주 ( Deuk Ju Kim ),정문기 ( Moon Ki Jeong ),남상용 ( Sang Yong Nam ) 한국공업화학회 2015 공업화학 Vol.26 No.1

본 리뷰에서는 에너지분야 응용을 위해 사용된 이온교환막을 이용한 분리막 공정에 대하여 정리하였다. 이온교환막은 기능, 균일상, 불균일상과 같은 형태, 사용된 고분자의 종류에 따라 구분되었으며, 양이온 및 음이온 교환막을 제조하 기 위한 다양한 방법에 대하여 논문을 참조하여 정리하였다. 이온교환막을 제조하기 위한 최신 연구결과 동향이 보고 되었으며, 본 리뷰에서는 분리막의 제조 및 발전되어온 내용과, 분리막을 미래지향적 기술에 사용하기 위한 잠재적 응용분야에 대하여 논의하였다. In this review, we summarized some of membrane processes using the ion exchange membrane typically used in energy applications. Ion exchange membranes are classified according to their functions, formations (e.g. heterogeneous, homogeneous), and polymer type. Furthermore, various methods to prepare cation exchange membranes and anion exchange membranes were discussed in detail and also illustrated through a thorough review of the literature works. There are numerous reports highlighting recent research trends in the ion exchange membrane fabrication, however, in this review we will focus more on discussing the development made in ion exchange membranes and their potential usages in future technologies.

TOC 와 6 시그마의 협력 방안

정남기(Nam Kee Chung),정문기(Moon Ki Jeong) 한국품질경영학회 2001 품질혁신 Vol.2 No.1

6시그마 품질경영 활동은 고객관점에서 품질의 결함을 찾고 이를 향상시킴으로써 고객만족과 수익향상에 큰 기여를 한 것이 사실이다. 그렇지만 품질개선 활동을 확장하여 경영전략으로 발전시키는 데에는 몇가지 문제점들이 지적되고 있다. 경영성과 척도로서 시그마 수준을 일률적으로 적용하는 것이 그 예이다. TOC(Theory of Constraints)는 시스템 사고에 의한 경영전략을 제시하는 이론이다. 이 논문은 TOC의 관점에서 6시그마의 한계를 조명하고, TOC와 6시그마의 상호협력방안을 모색해 본다.

마이크로 구조를 가진 패드를 이용한 MEMS CMP 적용에 관한 연구

박성민(Sungmin Park),정석훈(Sukhoon Jeong),정문기(Moon ki Jeong),박범영(Boumyoung Park),정해도(Heado Jeong) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월

Chemical-mechanical polishing, the dominant technology for LSI planarization, is trending to play an important function in micro-electro mechanical systems (MEMS). However, MEMS CMP process has a couple of different characteristics in comparison to LSI device CMP since the feature size of MEMS is bigger than that of LSI devices. Preliminary CMP tests are performed to understand material removal rate (MRR) with blanket wafer under a couple of polishing pressure and velocity. Based on the blanket CMP data, this paper focuses on the consumable approach to enhance MEMS CMP by the adjustment of slurry and pad. As a mechanical tool, newly developed microstructured (MS) pad is applied to compare with conventional pad (IC1400-k, Nitta-Haas), which is fabricated by micro molding method of polyurethane. To understand the CMP characteristics in real time, in-situ friction force monitoring system was used. Finally, the topography change of poly-si MEMS structures is compared according to the pattern density, size and shape as polishing time goes on.

산화막 CMP에서 리테이너 링 압력이 연마 형상과 응력분포에 미치는 영향

배재현(Jae Hyun Bae),이현섭(Hyun Seop Lee),정문기(Moon Ki Jeong),이영균(Young Kyun Lee),신운기(Woon Ki Shin),정해도(Hae Do Jeong) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.4