Effects of Thermal Treatment on Electrical Conductivity and Hardness of Polyaniline-Silica Composites

Young Been Lee(이영빈),Sung Kyu Jang(장성규),Chung Hyoi Park(박정회),Felix Sunjoo Kim(김선주) 한국고분자학회 2019 폴리머 Vol.43 No.5

전도성 고분자의 물리적 특성은 전자소자 응용에 큰 영향을 끼친다. 본 고에서는 열처리에 의한 폴리아닐린과 실리카 복합체의 기계적 특성과 전기전도도의 영향에 대해 분석하였다. 아닐린과 실리카 전구체의 혼합 수용액과 산화제 수용액을 순차적으로 떨어뜨려 전도성 복합체 박막을 만들고 열처리를 진행하였다. 분광분석 결과를 통해 에메랄딘염 상태의 폴리아닐린과 실리카 네트워크가 형성되었음을 확인하였다. 또한 나노인덴테이션을 통해 복합체의 경도가 순수 폴리아닐린보다 높은 것을 확인했으나, 열처리 온도에 큰 영향을 받지 않았다. 전기전도도는 5.5 S/cm에서 1.9 S/cm로 감소하는 경향을 확인했는데, 이는 열처리에 의한 디도핑의 결과로 분석된다. Physical stability of conducting polymers is considerably important for their applications in electronics. Here, we studied the thermal annealing effects of conducting polyaniline (PANI) composites with a sol-gel silica on their mechanical and electrical properties. Films were prepared onto a substrate by simple drop-casting method using solutions including aniline, tetraethyl orthosilicate (TEOS), and ammonium persulfate. Spectroscopic analyses confirm the emeraldine-salt phase of PANI and the presence of silica network in the film. Nanoindentation measurement showed that, although the improvement was observed in the PANI/TEOS hybrid films, the annealing temperature was not a significant factor for the hardness. The electrical conductivity of the composite decreased from 5.5 to 1.9 S/cm after annealing, due to the slight dedoping of PANI by heat-induced removal of the HCl dopant.

Effects of Electron-beam Irradiation on Electrical and Mechanical Properties of Conductive PEDOT:PSS/Silane Aerogels

Jaehwan Shin(신재환),Young Been Lee(이영빈),Felix Sunjoo Kim(김선주) 한국고분자학회 2021 폴리머 Vol.45 No.2

전도성 고분자 복합체 PEDOT:PSS에 실란 전구체인 TEOS 또는 GOPS를 혼합하여 고분자 에어로젤을 제작하고, 전자선 조사 공정에 따른 비저항과 스트레스-스트레인 특성을 연구하였다. PEDOT:PSS/실란 에어로젤은 혼합 수분산액의 균질화와 동결 건조를 통해 제작하였으며, 복합체 에어로젤에 대한 전자선 조사선량은 1에서 50 kGy까지 달리하였다. 용매 증기 처리를 통해 전도도를 향상시킨 에어로젤의 저항은 전자선 조사에 따라 증가하였다. PEDOT:PSS/TEOS 에어로젤은 전자선 조사에 따라 경직성이 증가하는 경향을 보였으나, PEDOT:PSS/GOPS 샘플은 경직도가 1~5 kGy에서 최대를 보였다. 이러한 경향 차이는 전자선 조사에 의한 공유결합 절단과 가교 기작의 경쟁에 따른 것으로 보인다. We prepared polymer aerogels based on a conducting polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and silane precursors, such as tetraethylorthosilicate (TEOS) and (3-glycidyloxypropyl)trimethoxysilane (GOPS), and investigated their specific resistance and stress–strain behaviors as a function of electronbeam dose. PEDOT:PSS/silane aerogels were easily made by homogenizing and freeze-drying from the aqueous mixtures. The composite aerogels were irradiated by the high-energy electron beams with a dose ranging from 1 to 50 kGy. Solvent vapor treatment was also used to see the effects of irradiation on the properties of the resulting aerogels. The resistance of high-conductivity aerogels increased when irradiated. PEDOT:PSS/TEOS aerogels became stiffer when irradiated, whereas PEDOT:PSS/GOPS samples peaked the stiffness at 1~5 kGy. Different behaviors were likely from two competitive mechanisms of chemical scission and cross-linking caused by electron beams.

麝香蘇合元이 再灌流裝置下의 흰쥐 心臟에 미치는 影響

李英彬,文祥官,高昌男,曺基湖,金永錫,裵亨燮,李京燮 대한한방성인병학회 1997 韓方成人病學會誌 Vol.3 No.1

ACKGROUND The stenosis of the coronary artery results in a decrease in the myocardial oxygen supply, ischemia and infarction. Sahyangsohabwon as a drug of fragrance, is generally regarded to have the effect of waking up the patient from unconsciousness and promoting the flow of Qi(氣) by warming channel. METHODS The purpose of this study is to find whether Sahyangsohabwon is effective or not in curing ischemia in isolated heart of rats and to measure the degree of its curing effect. In this study, under the Langendorff apparatus, ischemia was induced in isolated hearts of Sprague-Dawley rats by ceasing the perfusion for 20 minutes. Subjects were divided into a normal saline orally administered group(control group), a Sahyangsohabwon orally administered group(sample A), a Sahyangsohabwon orally administered perfused group(sample B), and a Sahyangsohabwon perfused group(sample C). The heart rates, left ventricular pressure, myocardial dilatation/contraction ratio, coronary flow and dry weight of the four groups were measured and compared in order to assess the influence of Sahyangsohabwon on isolated heart's recovering ability from ischemia. RESULT 1. Heart rates were increased significantly in Sahyangsohabwon orally administered group in comparison with control group(p<0.01). 2. Left ventricular pressure were increased significantly in Sahyangsohabwon orally administered and perfused group(p<0.01) and Sahyangsohabwon perfused group(p<0.05) in comparison with control group. 3. While there were no differances in each group's abilities of myocardial contraction, the ability of myocardial dilatation of Sahyangsohabwon perfused group was significantly greater than that of control group(p<0.05). 4. GPT was decreased significantly in Sahyangsohabwon perfused group(p<0.05). 5. GOT showed a significant decrease in Sahyangsohabwon orally administered and perfused group(p<0.01). 6. LDH was significantly decreased in Sahyangsohabwon orally administered group and Sahyangsohabwon orally administered and perfused group(0.01). 7. There was no significant change in CPK and the dry weight of isolated heart(N.S.). CONCLUSION According to the result above, Sahyangsohabwon is effective and to recover in the isolated perfused heart. Especially, the effect of Sahyangsohabwon is greater in Sahyangsohabwon perfused group than in Sahyangsohabwon orally administered group. The two important results of this study as follows: Firstly, the effect of Sahyangsohabwon tranditionally used on heart disease was proved statistically under the Langendorff apparatus. Secondly, on the basis of this study, the effect of other medications on myocardial ischemia can be evaluated in further studies.

U-Turn의 적정신호시간 모형구축에 관한 연구

오윤표,안영종,이영빈 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

In metropolitan, main streets manages 60-80% of the whole traffic in Korea even though its limited area and short extension. Main streets in urban has suffered congestion and a falling-off in capability of transportation due to its frequent discontinuity and disconnection. Especially Left-turn traffic mainly generates a shortage of fluidity in intersection although most intersection adopts Left-turn because of the peculiarity of traffic flows. To breakthrough this deterioration, U-turn system goes into effect in intersection of most main streets by reducing Left-turn phase or banning Left-turn at specific intersections to increase the fluidity of main direction. However, U-turn system lacks continuity and reveals security deficits because its legal basis and safety standard are not definitive. Therefore, this study, firstly, investigates the special characteristics of U-turn system, analyzes its effects based on the case of Busan city making the survey of drivers' awareness on U-turn. Then, secondly, This study aims to suggest more efficient and executive operating program for U-turn system by constructing proper Signal time model for U-turn.

麝香蘇合元이 再灌流裝置하의 흰쥐 심장에 미치는 영향

李京燮,金永錫,曹基湖,李英彬,裵亨燮 慶熙大學校韓醫科大學韓醫學硏究所 1996 慶熙韓醫大論文集 Vol.19 No.2

BACKGROUND The stenosis of the coronary artery results in a decrease in the myocardial oxygen supply, ischemia and infarction. Sahyangsohabwon as a drug of fragrance, is generally regarded to have the effect of waking up the patient from unconsciousness and promoting the flow of Qi(氣) by warming channel. METHODS The purpose of this study is to find whether Sahyangsohabwon is effective or not in curing ischemia in isolated heart of rats and to measure the degree of its curing effect. In this study, under the Langendorff apparatus, ischemia was induced in isolated hearts of Sprague-Dawley rats by ceasing the perfusion for 20 minutes. Subjects were divided into a normal saline orally administered group(control group), a Sahyangsohabwon orally administered group(sample A), a Sahyangsohabwon orally administered perfused group(sample B), and a Sahyangsohabwon perfused group(sample C). The heart rates, left ventricular pressure, myocardial dilatation/contraction ratio, coronary flow and dry weight of the four groups were measured and compared in order to assess the influence of Sahyangsohabwon on isolated heart's recovering ability from ischemia. RESULT 1. Heart rates were increased significantly in Sahyangsohabwon orally administered group in comparison with control group(p<0.01). 2. Left ventricular pressure were increased significantly in Sahyangsohabwon orally administered and perfused group(p<0.01) and Sahyangsohabwon perfused group(p<0.05) in comparison with control group. 3. While there were no differences in each group's abilities of myocardial contraction, the ability of myocardial dilatation of Sahyangsohabwon perfused group was significantly greater than that of control group(p<0.05). 4. GPT was decreased significantly in Sahyangsohabwon perfused group(p<0.05). 5. GOT showed a significant decrease in Sahyangsohabwon orally administered and perused group(p<0.01). 6. LDH was significantly decreased in Sahyangsohabwon orally administered group and Sahyangsohabwon orally administered and perfused group(0.01). 7. There was no significant change in CPK and the dry weight of isolated heart(N.S.). CONCLUSION According to the result above, Sahyangsohabwon is effective and to recover in the isolated perfused heart. Especially, the effect of Sahyangsohabwon is greater in Sahyangsohabwon perfused group than in Sahyangsohabwon orally administered group. The two important results of this study as follows : Firstly, the effect of Sahyangsohabwon traditionally used on heart disease was proved statistically under the Langendorff apparatus. Secondly, on the basis of this study, the effect of other medications on myocardial ischemia can be evaluated in further studies.