• Korean Chemical Engineering Research
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• 제55권6호
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• pp.830-836
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• 2017

콜로이드 실리카를 실란커플링제인 GPTMS (3-glycidoxypropyl trimethoxysilane)와 반응시킴에 의해 친수성 코팅용액을 제조하였다. 또한 이 친수성 코팅 용액을 폴리카보네이트 기재 위에 스핀코팅 시킨 후 $120^{\circ}C$에서 열경화 시킴에 의해 친수성 코팅 도막이 제조되었다. 이 과정 중 콜로이드 실리카의 평균 크기를 15 nm, 25 nm, 45 nm로 각각 변화시켜 코팅 도막의 물성에 미치는 영향을 살펴보았다. 그 결과 25 nm 크기의 콜로이드 실리카를 사용하여 제조된 코팅 도막은 $20^{\circ}$의 낮은 접촉각과 H의 우수한 연필경도를 나타내었다. 반면에 15 nm와 45 nm 크기의 콜로이드 실리카로 제조된 코팅 도막은 각각 $27^{\circ}$와 $36^{\circ}$의 높은 접촉각과 H와 B의 연필경도를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2637-2643
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• 2010

In order to develop a new line injection system for spin draw yarn (FD SDY) fibers, the effect of various parameters in extrusion and melt line conditions on the dispersion and distribution of $TiO_2$ particles within FD PET fibers was investigated. As a result, the dispersibility of $TiO_2$ particles in a PET matrix is found to depend on the particle size and its surface characteristics. Surface modification of $TiO_2$ by dimethyl polysiloxane resulted in the improved dispersibility and affinity of $TiO_2$ particles in the PET matrix. Especially, residence time, mixing temperature, and mixing shear rate in the new line injection system under the SDY spinning process were very important parameters to minimize the agglomeration of $TiO_2$ particles. The FD SDY prepared by the new line injection system was superior to those using the polymerization process and the conventional masterbatch chip dosing process in the color-L and color-b values of the fibers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.308-311
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• 2003

The mesoporous TiO2 film for the dye-sensitized solar cell was prepared by the spin coating using nano particle $TiO_2$ slurry. In order to obtain the good dispersion of nano size $TiO_2$ particles in slurry, the pH of solvent, the sort and quantity of solvent additive and the quantity of surfactant were adjusted. The experimental range of pH was $2\;{\sim}\;4$. The basic solvent for slurry was dilute $HNO_3$ and the solvent additives were ethylene glycol, propylene glycol and butylene glycol. The degree of particle dispersion was indirectly estimated by the viscosity of slurry and the microstructure after sintering. As results, the lower the pH of solvent was the lower the viscosity of the slurry became. The addition of ethylene glycol and propylene glycol to dilute $HNO_3$ brought about the lowering of viscosity and the enhancement of stability in slurry. The addition of surfactant lowered the viscosity of slurry. It was possible to obtain the homogeneous and uniformly dispersed mesoporous TiO2 film using the dilute HNO3 solvent of pH 2 with the addition of ethylene glycol, propylene glycol and neutral surfactant.

• 한국진공학회지
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• 제17권6호
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• pp.549-554
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• 2008

수소 플라즈마 처리된 유리 기판에 스핀 코팅 시스템을 이용하여 nickel chloride를 코팅하여 단백질칩 플레이트를 제조하였다. 다양한 플라즈마 처리 시간대에서 histidine tagged 단백질의 부착 능력 특성을 연구하였다. 유리 기판 표면에서 nickel chloride와 단백질 특성을 particle size analysis를 이용하여 관찰하였고, 단백질의 부착 능력 정도를 bio imaging analyzer system으로 측정하였다. 실험 결과에 따르면, 플라즈마 처리 시간이 증가할수록 단백질 부착 능력은 감소하는 것으로 나타났다. 기판 표면에서의 단백질 부착능력 특성에 관한 mechanism은 본문의 결과 및 토의에서 논의되었다. 플라즈마 처리된 단백질칩 기판에 대한 표면 안정화는 바이오센서 시장에서 큰 관심을 끌 것으로 기대된다.

• 한국결정성장학회지
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• 제24권3호
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• pp.94-98
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• 2014

$LiCoO_2$는 박막 베터리의 양극재료로써 많은 관심을 받고 있다. 본 연구에서는 스핀 코터를 이용한 졸-겔 합성공정과 열처리 과정에 의해서 Au 지지체 위에 $LiCoO_2$ 박막을 합성하였다. 합성된 박막의 구조는 X-선회절분석, 라만분광 광도계를 이용하여 분석하였다. 박막의 입자 형태는 전자현미경에 의해 관찰하였다. X-선회절분석, 라만분광광도계의 결과로부터, $550^{\circ}C$와 $750^{\circ}C$에서 합성된 박막은 스피넬구조와 층상 암염 형 구조를 가지는 박막으로 보이며, $650^{\circ}C$에서 합성된 박막은 층상 암염 형 구조와 스피넬 구조가 혼재되어져 있는 것으로 생각된다. $750^{\circ}C$에서 합성된 박막은 다른 낮은 온도에서 합성된 박막보다 큰 결정질의 균일한 분포의 입자를 가지는 것으로 확인되었다.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3593-3599
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• 2010

In an original effort, this lab attempted to employ polystyrene nanoparticles as a template for the synthesis of ordered and highly porous macroporous $SiO_2$ thin films, utilizing their high combustion temperature and narrow size distribution. However, polystyrene nanoparticle thin films were not obtained due to the low interaction between individual particles and between the particle and silicon substrate. However, polystyrene-polyacrylic acid (PS-AA) colloidal particles of a core-shell structure were synthesized by a one-pot miniemulsion polymerization approach, with hydrophilic polyacrylic acid tails on the particle surface that improved interaction between individual particles and between the particle and silicon substrate. The PS-AA thin films were spin-coated in the thickness ranges from monolayer to approximately $1.0\;{\mu}m$. Using the PS-AA thin films as sacrificial templates, macroporous $SiO_2$ thin films were successfully synthesized by vapor deposition or conventional solution sol-gel infiltration methods. Inspection with field emission scanning electron microscopy (FE-SEM) showed that the macroporous $SiO_2$ thin films consist of interconnected air balls (~100 nm). Typical macroporous $SiO_2$ thin films showed ultralow refractive indices ranging from 1.098 to 1.138 at 633 nm, according to the infiltration conditions, which were confirmed by spectroscopy ellipsometry (SE) measurements. This research shows how the synthetic control of the macromolecule such as hydrophilic polystyrene nanopaticles and silicate sol precursors innovates the optical properties and processabilities for actual applications.

• 천문학회지
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• 제46권3호
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• pp.97-102
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• 2013

In the present work, we prove the validity of two theorems on null-paths in a version of absolute parallelismgeometry. A version of these theorems has been originally established and proved by Kermak, McCrea and Whittaker (KMW) in the context of Riemannian geometry. The importance of such theorems lies in their applications to derive a general formula for the redshift of spectral lines coming from distant objects. The formula derived in the present work can be applied to both cosmological and astrophysical redshifts. It takes into account the shifts resulting from gravitation, different motions of the source of photons, spin of the moving particle (photons) and the direction of the line of sight. It is shown that this formula cannot be derived in the context of Riemannian geometry, but it can be reduced to a formula given by KMW under certain conditions.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.321-321
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• 2010

The PEDOT:PSS layer is usually used as hole transporting layer for the polymer bulk heterojunction solar cells. However, the interface between ITO and PEDOT:PSS is not stable and the chemical reaction between ITO and PEDOT can result in degraded device performance. We used the tungsten oxides as a hole transport layer by spin-coating. The $WO_3$ nanoparticles were well dispersed in ammonium hydroxide and deionized water and formed thin layer on the ITO anode. We found that $WO_3$ surface is more hydrophobic than the bare ITO or PEDOT:PSS-coated surfaces. The hydrophobic surfaces promote an ordered growth of P3HT films. A higher degree of P3HT ordering is expected to improve the hole mobility and the lifetime of the device using the tungsten oxide showed better stability compared to the device using the PEDOT:PSS.

• Journal of Korean Vacuum Science & Technology
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• 제6권3호
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• pp.116-119
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• 2002

A performance of a new positron polarimeter is investigated by simulation using a charged-particle trajectory program. The results of the ray tracing are presented along with the details of the design parameters and projected system performance. A ray tracing analysis indicates that this design is capable of effectively transmitting positrons at beam energies varying from 0.1 to 30 keV within the beam diameter of 2-6mm. However, the observed reflection of the positrons(lower than 2 keV) at 12 kGauss indicated that further refinement of beam design is needed to produce a better positron polarimeter.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.183-183
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• 2012

In the era of 45 nm or beyond technology, conventional etch mask using photoresist showed its limitation of etch mask pattern collapse as well as pattern erosion, thus hard mask in etching became necessary for precise control of etch pattern geometry. Currently available hard mask materials are amorphous carbon and polymetric materials spin-on containing carbon or silicon. Amorphous carbon layer (ACL) deposited by PECVD for etch hard mask has appeared in manufacturing, but spin-on carbon (SOC) was also suggested to alleviate concerns of particle, throughput, and cost of ownership (COO) [1]. SOC provides some benefits of reduced process steps, but it also faced with wiggling on a sidewall profile. Diamond like carbon (DLC) was also evaluated for substituting ACL, but etching selectivity of ACL was better than DLC although DLC has superior optical property [2]. Developing a novel material for pattern hard mask is very important in material research, but it is also worthwhile eliminating a potential issue to continuously develop currently existing technology. In this paper, we investigated in-situ dry-cleaning (ISD) monitoring of ACL coated process chamber. End time detection of chamber cleaning not only provides a confidence that the process chamber is being cleaned, but also contributes to minimize wait time waste (WOW). Employing Challenger 300ST, a 300mm ACL PECVD manufactured by TES, a series of experimental chamber cleaning runs was performed after several deposition processes in the deposited film thickness of $2000{\AA}$ and $5000{\AA}$. Ar Actinometry and principle component analysis (PCA) were applied to derive integrated and intuitive trace signal, and the result showed that previously operated cleaning run time can be reduced by more than 20% by employing real-time monitoring in ISD process.