• 한국식품조리과학회지
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• 제8권3호
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• pp.291-296
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• 1992

The physicochernical properties of Korean buckwheat starches were investigated. The results were as follows; 1. Water binding capacity of kangwon hull buckwheat starch was 106.55% and that of Kangwon rice buckwheat was 99.35%. 2. The pattern of change in swelling power of hull buckwheat starch for increasing temperature started to increase at 60$^{\circ}C$ and increased rapidly from 80$^{\circ}C$, and that of rice buckwheat increased slowly from 60$^{\circ}C$ to 90$^{\circ}C$. 3. The ranges of gelatinization temp. of hull buckwheat and rice buckwheat starches were 70~75$^{\circ}C$ and 75~85$^{\circ}C$, respectively. 4. The blue value of hull buckwheat starch and rice buckwheat starch were 6.25 and 0.62, respectively. 5. The alkali number of hull buckwheat starch and rice buckwheat starch were 1.28 and 3.68 respectively. 6. The amylose content of hull buckwheat and rice buckwheat starch were 32.26% and 38.09%. 7. Periodate oxidation of hull buckwheat starch resulted that amylose had me average molecular weight of 103, 004, degree of polymerizatlon of 572 and amylopectin had me degree of branching of 7.64, glucose unit per segment of 13.09, and periodate oxidation of rice buck wheat starch resulted mat amylose had me average molecular weight of 125, 654, degree of polymerization of 698 and amylopectin had degree of branching of 6.59, glucose unit per segment of 15.16.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.928-932
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• 2008

A glassy carbon electrode (GCE) modified with poly(p-aminobenzene sulfonic acid) [Poly(p-ABSA)] film is fabricated by voltammetric technique in phosphate buffer solution (pH 8.0) containing $5.0\;{\times}\;10^{-3}\;mol\;L^{-1}$p- ABSA. Electrochemical behaviors of tryptophan at the Poly(p-ABSA) film electrode are investigated with voltammetry. The results indicate that the electrochemical response of tryptophan is improved significantly in the presence of poly(p-ABSA) film. Compared with the bare glassy carbon electrode, the Poly(p-ABSA) film electrode remarkably enhances the irreversible oxidation peak current of tryptophan. Some parameters such as voltammetric sweeping segments for the electrochemical polymerization, pH, accumulation potential and accumulation time are optimized. Under the optimal conditions, the oxidation peak current is proportional to tryptophan concentration in the range of $1.0\;{\times}\;10^{-7}$ to $1.0\;{\times}\;10^{-6}\;mol\;L^{-1}$, and $2.0\;{\times}\;10^{-6}$ to $1.0\;{\times}\;10^{-5}\;mol\;L^{-1}$ with a detection limit of $7.0\;{\times}\;10^{-8}\;mol\;L^{-1}$. The proposed procedure is successfully applied to the determination of tryptophan in a commercial amino acid oral solution.

• 대한화학회지
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• 제40권7호
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• pp.467-473
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• 1996

유기 전도성고분자들 중 100-400${\Omega}^{-1}cm^{-1}$으로 전도도가 큰 피롤 고분자는 공기 중에서 산화되어 전도성이 저하되는데, 이를 막기 위해 피롤을 먼저 일정량 중합한 후 산소에 내성이 큰 티오펜 고분자를 일정량 끼워심기 중합시켜 이와 같은 단점이 보완된 고분자 복합체를 만들고 그 때의 중합 속도를 측정하였다. 피롤 고분자를 먼저 1.70C$cm^{-2}$만큼 전기적으로 중합시킨 후 그 위에 티오펜 고분자를 0.34C$cm^{-2}$로 전기적 중합시켰을 때 그 산화-환원 특성이 개선되었으며, 3개월 동안 공기 중에 방치한 것의 순환 전압-전류 특성이 처음것과 잘 이치하였다. 티오펜의 중합 속도는 백금 전극 위에서 피롤 고분자를 1.70C$cm^{-2}$로 일정량을 입힌 전극에서 행했을 때 속도상수 값은 각각 $3.89{\times}10^{-8}$과 $6.07{\times}10^{-8}cms^{-1}$이었고, 표준속도상수는 각각 $5.16{\times}10^{-6}$ 과 $3.94{\times}10^{-4} cms^{-1}$이었다. 또, 피롤을 입힌 전극에서의 전극촉매속도는 $3.45{\times}10^{-3}cm^3mol^{-1}s^{-1}$이었다. 이와같이 피롤로 수식한 전극에서의 고정된 피롤 피막층은 촉매적 기능을 가지고 있음을 알 수 있고, 티오펜을 중합할 때의 반응은 고분자 피막 내에서 전하전달과 확산이 지배적인 과정이었다. 반면에 백금 전극에 티오펜을 중합할 때는 전자 전달이 지배적이 과정으로 나타났다.

• KSBB Journal
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• 제23권4호
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• pp.340-344
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• 2008

CiP를 이용한 유기합성은 주로 유기용매와 완충용액을 섞어서 반응을 한다. 하지만 단순히 유기용매 상에서 효소의 활성도를 측정한 것이 아니라, 과산화수소가 있을 경우에 효소의 활성도를 측정한 결과는 예상과는 다르게 순수한 완충용액에서 보다 유기용매를 포함하고 있는 것이 더 높게 나타났다. 또한 유기용매의 비율을 증가가 될수록 효소의 활성도가 더 높게 나타났으며, 특히 2-propanol이 33%가 포함이 된 경우에는 순수한 완충용액보다 효소의 활성도가 크게 증가가 되는 것을 관찰을 할 수가 있었다. 이러한 효소의 활성도가 유기용매가 포함이 된 조건에서 높게 나는 이유는 유기용매가 CiP에 의해 생성된 반응성이 높은 라디칼을 포집을 하여서, CiP의 활성 부위인 heme의 파괴를 막는 것에 크게 기여하는 것으로 판단이 되었다.

• 대한기계학회논문집A
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• 제28권10호
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• pp.1534-1540
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• 2004

This study aims to obtain fundamental understandings involving the manufacturing processes of nano-composites with chemically surface-modified multi-walled carbon nanotubes(MWCNTs), and explore the role of functionalized MWCNTs in the epoxy/MWCNT composites. For this purpose, MWCNTs were purified by the thermo-chemical oxidation process, and incorporated into an epoxy matrix by in situ polymerization process, the surface of MWCNTs were functionalized with carboxyl functions which were demonstrated by an infrared spectroscopy. The mechanical properties of epoxy/MWCNT nano-composites were measured to investigate the role of a chemically functionalized carbon nanotubes. To improve the dispersion quality of MWCNTs in the epoxy matrix, methanol and acetone were exploited as dispersion media with sonification. The epoxy/MWCNT nano-composites with 1 or 2 wt.％ addition of functionalized carbon nanotubes show an improved tensile strength and wear resistance in comparison with pure epoxy, which shows the mechanical load transfer improves through chemical bonds between epoxy and functionalized MWCNTs. The tensile strength with 7 wt.％ functionalized MWCNTs increases by 28％ and the wear resistance is dramatically improved by 100 times.

• Korea-Australia Rheology Journal
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• 제18권2호
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• pp.103-107
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• 2006

Organic-inorganic composite of polyaniline and barium titanate (PANI-$BaTiO_3$) was synthesized via an in-situ oxidation polymerization of aniline in the presence of barium titanate ($BaTiO_3$) nanoparticles dispersed in an acidic medium. Barium titanate has large electric resistance and relatively high dielectric constant which is one of the essential properties for its electrorheological (ER) applications. The microstructure and composition of the obtained PANI/$BaTiO_3$ composite were characterized by SEM, FT-IR and XRD. In addition, we also employed a rotational rheometer to investigate the rheological performance of the ER fluids based on both pure PANI particle and PANI/$BaTiO_3$ composite. It was found that the composite materials possess much higher yield stresses than the pristine PANI due to unique dielectric properties of the inorganic $BaTiO_3$ particles. Finally, we also examined dynamic yield stress by analyzing its extrapolated yield stress data as a function of electric field strengths. Using the critical electric field strengths deduced, we further found that the universal yield stress equation collapses their data onto a single curve.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1341-1345
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• 2011

A novel ruthenium(II) complex, [$RuCl_2(DMSO)_2$(PhenTPy)] has been synthesized by the condensation of $RuCl_2(DMSO)_4$ with (1-(1,10-phenanthrolinyl)-2,5-di(2-thienyl)-1H-pyrrole)[PhenTPy] in $CHCl_3$ solution. The [$RuCl_2(DMSO)_2$(PhenTPy)] complex modified electrode was fabricated through the electropolymerization of the monomer in a 0.1 M tetrabutylammonium perchlorate (TBAP)/$CH_2Cl_2$ solution, to take advantage of the electronic communication between metal ion center by the conjugated backbone. The UV-visible spectroscopy (UV), mass spectrometry (MS), and cyclic voltammetry (CV) were employed to characterize the [$RuCl_2(DMSO)_2$(PhenTPy)] complex and its polymer (poly-Ru(II)Phen complex). The poly-Ru(II)Phen complex modified electrode exhibited an electrocatalytic activity to the oxidation of acetaminophen and the catalytic property was used for the analysis of acetaminophen at the concentration range between 0.09 and 0.01 mM in a phosphate buffer solution (pH 7.0).

• 폴리머
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• 제25권6호
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• pp.826-832
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• 2001

본 연구에서는 폴리피를 (PPy)/gold/mylar 형태의 두 겹의 전기활성 구동기를 제작하였으며, 도판트의 종류에 따른 굽힘 구동 특성에 관한 연구를 수행하였다. 전도성 고분자는 전기적으로 산화/환원이 될 때에는 도판트의 이동에 의하여 부피 변화를 수반하게 된다. 도판트의 크기에 따라, 서로 다른 구동 특성을 나타내었는데, toluene sulfonate와 같은 작은 크기의 도판트는 산화/환원에 따라 PPy 필름의 내외로 자체 이동이 가능하며, 산화시에 PPy의 팽창이 관찰되었다. 그러나, dodecylbenzenesulfonate와 같은 커다란 도판트가 함유된 PPy는 산화/환원시에는 이들의 이온들은 움직임이 없는 것으로 나타났으며 환원시에 작은 양이온($Na^+$)이 필름내부로 유입되며 부피가 증가하는 현상이 관찰되었다.

• 공업화학
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• 제29권4호
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• pp.363-368
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• 2018

Polyoxometalates (POMs)는 뛰어난 특성과 전기 화학 응용 분야에 대한 많은 잠재력을 가지고 있다. POM은 매우 잘 녹는 성질 때문에 전기화학 소자에서 POM의 잠재력을 최대한 활용하기 위해서는 다양한 기능성 재료에 POM을 고정화하는 과정이 필수이다. 본 논문에서는 우리는 최근 개발된 고정화 방법인 나노 카본 및 전도성 고분자와 같은 전도성 나노 물질에 POM을 도입하는 기술들에 대해서 논하고자 한다. Langmuir-Blodgett 기술, 층별 자기 조립 및 전기화학 in-situ 중합을 사용하여 전도성 고분자 매트릭스 및 POM을 나노 카본으로 도입할 수 있는 다양한 고정화 전략을 소개한다. 또한 우리는 POM의 응용 분야인 물 산화용 전극 촉매, 리튬 이온 배터리, 슈퍼커패시터 및 전기화학적 바이오 센서 등의 다양한 전기 화학 응용 분야를 다룬다.

• 펄프종이기술
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• 제43권2호
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• pp.40-48
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• 2011

To build up the conservativeness of aged paper heritages, the strength reinforcement treatment using various cellulose derivative solutions was considered. Hand-made Hanji prepared by traditional papermaking technique was firstly simulated in order to modify the overall of paper properties like aged paper heritages by accelerated ageing treatment at $150^{\circ}C$ for 24 hours, and then the ageing stability of Hanji was verified through the secondary accelerated ageing at $150^{\circ}C$ for 12 hours. The physical properties of aged Hanji were improved by applying with cellulose derivative solutions. The ageing stability for physical, optical (L, brightness, opacity, yellowness) and chemical (oxidation index, degree of polymerization) properties of aged Hanji treated with all kinds of cellulose derivative solutions was also good compared to those of untreated samples, especially using MC solution. Therefore, it was that a kind of MC solution would be well-suited for the strength reinforcement treatment of aged paper heritages.