• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.19-20
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• 1994

막(Membrane)을 이용한 기체분리는 막층 네에서의 기체분자의 투과성의 차이를 이용하여 기체분리를 행하는 것으로 공기중 산소의 분리 (산소부화막 이라고도 한다), 수성가스중의 수소의 농축분리, 탄화수소가스중 이산화탄소의 분리, 그 외에 산업폐가스 (황화수소, 일산화탄소, 아황산가스 등)의 분리등이 있다. 이 중 산소부화막은 의료용 산소공급장치나 산업용 용광로의 연소효율 증진에 효과적으로 이용될 수 있으며 산업폐가스이 분리공정은 환경공학적 측면에서 활용이 가능하다.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.425-434
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• 2006

The operability and productivity of continuous processes, especially in petrochemical industries have made remarkable improvement during the past twenty years through advanced process control (APC) typified by model-based predictive control. On the other hand, APC have not been actively practiced in industrial batch processes typified by batch polymerization reactors. Perhaps the main cause for this has been the lack of reliable batch process APC techniques that can overcome the unique problems in industrial batch processes. Recently, some noteworthy progress is being made in this area. New high-performance batch process control techniques that can accommodate and also overcome the unique problems of industrial batch processes have been proposed on the basis of iterative learning control (ILC). In this review paper, recent advancement in the batch process APC techniques are presented, with a particular focus on the variations of the so called Q-ILC method, with the hope that they are widely practiced in different industrial batch processes and enhance their operations.

• Journal of the Korean Ceramic Society
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• v.36 no.3
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• pp.266-273
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• 1999

본 연구에서는 겔캐스팅법의 제조공정 확립을 위하여 분산제의 분자구조가 질화규소 슬립의 점성특성 및 성형체의 상대밀도와 기계적 특성에 미치는 영향을 조사하였다. 슬립과 겔캐스팅 성형체의 제조방법은 기보고된 방법과 동일하게 하였다. 그 결과, 겔캐스팅 슬립의 점성은 분산제의 분자구조와 모노머와 분산제의 구성비율에 크게 의존하였다. PMAA 분산제를 사용한 슬립의 점성은 PAA 및 PAAm 분산제 보다 높은 점도를 나타내었다. 성형체의 상대밀도는 슬립의 농도에 크게 의존하였으며, 분산제양과 모노머의 양변화에는 그다지 변화가 없었다. 그리고, 겔캐스팅 성형체의 기계적 특성은 크게 모노머의 농도에 의존하였으며, 분산제양과 슬립의 농도에는 큰 변화가 없었다.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.120-122
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• 1998

현재 상업화되어있는 RO membrane으로는 크게 asymmetric membrane과 composite membrane으로 구분될 수 있다. Asymmetric membrane의 소재로는 Cellulose acetate나 Cellulose triacetate와 같은 것들이 사용되며 현재에도 많이 사용되고 있으나, 보다 더 우수한 성능을 갖는 분리막을 제조하기 위해 현재에는 주로 composite membrane 형태로 제조된다. 대부분의 composite membrane은 계면중합에 의해 제조되는데 대표적인 membranem으로는 FT-30이 있다. 이 밖에도 support의 표면을 직접 플라즈마 처리하여 복합막을 제조하는 공정이 있으며 polyactrylonitrile과 같은 membrane이 이에 속한다. 플라즈마 처리된 복합막은 처리 대상에 크게 영향을 받지 않고 support 표면에 crosslinking의 형태로 형성되기 때문에 active layer가 매우 안정하며 따라서 우수한 물리화학적 성질을 기대할 수 있다. 이밖에도 분리막 표면을 친수성 단량체로 플라즈마 처리함으로써 분리막 표면에 친수성을 부여하거나 관능기를 도입함으로써 불활성 표면을 활성화 시킬 수도 있는 등의 여러가지 장점을 가지고 있다.

• Korean Journal of Materials Research
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• v.6 no.11
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• pp.1082-1089
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• 1996

본 연구에서는 resorcinol과 formaldehyde를 이요하여 수상에서 축중합시켜 겔을 만든 후 저온 초임계 건조 공정을 이용하여 겔 구조의 변형없이 용매를 제거하여 내무 표면적과 같은 에어로겔의 최종 물성에 미치는 영향을 알아보기 위하여 고형분의 농도(2-5%)를 변화시켜 실험한 결과 초기 반응조건이 반응시간 및 최종물성에 변수가 됨을 알 수 있었다. 또한 제조된 에어로겔에 100-30$0^{\circ}C$까지 온도를 가하며 표면 특성을 분석한 결과 열을 가함에 따라 기공의 크기가 커지고 표면적이 감소됨을 관찰할 수 있었다.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.4
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• pp.265-270
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• 2016

Recently, many studies have been conducted on the nano-scale fabrication technology using twophoton- absorbed polymerization induced by a femtosecond laser. The nano-stereolithography process has many advantages as a technique for direct fabrication of true three-dimensional shapes in the range over several microns with sub-100 nm resolution, which might be difficult to obtain by using general nano/microscale fabrication technologies. Therefore, two-photon induced nano-stereolithography has been recently recognized as a promising candidate technology to fabricate arbitrary 3D structures with sub-100 nm resolution. Many research works for fabricating novel 3D nano/micro devices using the two-photon nano-stereolithography process, which can be utilized in the NT/BT/IT fields, are rapidly advancing.

• Journal of Adhesion and Interface
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• v.8 no.1
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• pp.8-14
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• 2007

Poly(urethane-methyl methacrylate) hybrid emulsions can be controlled with their thermal, mechanical and anti-chemical properties as plastic coating materials. In this study, water dispersed poly(urethane-methyl methacrylate) hybrid emulsions were prepared by prepolymer synthesis and soap free emulsion polymerization. For imparting hydrophilicity on polyurethane prepolymer, 2,2-bis (hydroxymethyl) propionic acid was added to the polyurethane prepolymer with methyl methacrylate monomer and was neutralizated by triethylamine (TEA). After neutralization, the prepolymer mixture was dispersed in the water phase with stable droplets. The synthesis was carried out with chain extension from the ethylene diamine and initiation of methyl methacrylate by soap free emulsion polymerization. Stable poly(urethane-methyl methacrylate) hybrid emulsion was successfully obtained with different synthetic conditions and acrylic monomer contents. Poly(urethane-methyl methacrylate) hybrid emulsion were characterized and compared with tensile strength, viscosity, and adhesion properties.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.159-173
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• 2012

UV-Curing technology can be classified into two categories for radical curing and cation curing. It also has mainly focused on surface finishing technology to improve functionality of various substrates such as plastics and metals. On the other hand, EB technology has dealt with cross-linking reactions as well as polymerization process to create novel functional materials. Both technologies have advantages in energy utilizing efficiency and environmental friendly when compared to conventional thermoset coatings. Consequently, UV cured coatings also permits a reduction in the $CO_2$ and VOCs emitted in the drying and curing process. This review mainly shows radical curing technology which is commonly used in UV curing coatings and also describes the technology trends of cation curing which has been attracted attention recently.

• Clean Technology
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• v.18 no.2
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• pp.123-143
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• 2012

Supercritical fluid technology (SFT) is recently one of the most new techniques, which has been interested various fields of related chemical industries. SFT is the most effective and practical technology with eco-friendly, energy-savings, and high efficiency as the technique using the advantages of supercritical fluid such as high solvation power, solubility, mass transfer rate, and diffusion rate. Especially, it is necessary to analyze, evaluate, and develop the potential of application techniques using SFT with these characterizations. Therefore in this review, the phase behavior in supercritical fluid at high temperature and pressure of monomers/polymers for the optimization of polymerization process are briefly described, and the preparation of molecularly imprinted polymers (MIPs) in supercritical fluid using supercritical polymerization and the performance evaluation of MIPs are introduced.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.330-335
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• 2018

A new approach for the fabrication of organic-organic conducting composite thin films using simultaneous co-vaporization vapor phase polymerization (SC-VPP) of two or more monomers that have different polymerization mechanisms (i.e., oxidation-coupling polymerization and radical polymerization) was reported for the first time. In this study, a PEDOT-PSMA composite thin film consisting of poly(3,4-ethylenedioxythiophene)(PEDOT) and poly(styrene-co-maleic anhydride)(PSMA) was prepared by SC-VPP process. The preparation of organic-organic conductive composite thin films was confirmed through FT-IR and $^1H-NMR$ analyses. The surface morphology analysis showed that the surface of PEDOT-PSMA thin film was rougher than that of PEDOT thin film. Therefore, PEDOT-PSMA exhibited lower electrical conductivity than that of PEDOT. But the conductivity can be improved by adding 2-ethyl-4-methyl imidazole as a weak base. The contact angle of PEDOT-PSMA was about $50^{\circ}$, as compared to $62^{\circ}$ for PEDOT. The demonstrated methodology for preparing an organic-organic conductive hybrid thin film is expected to be useful for adjusting intrinsic conductive polymer (ICP)'s surface properties such as mechanical, optical, and roughness properties.