http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 곽기섭(Giseop Kwak) (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
열유도 상분리에 의한 폴리디페닐아세틸렌 유도체의 급격한 형광증대
박효상(Hyosang Park),김희상(Heesang Kim),곽기섭(Giseop Kwak) 한국고분자학회 2021 폴리머 Vol.45 No.4
열유도 상분리에 따른 폴리디페닐아세틸렌 유도체인 poly[1-phenyl-2-(p-trimethysilyl)phenylacetylene](PTMSDPA)의 상변화와 형광특성을 조사하였다. 폴리머와 비슷한 용해도상수를 가지는 용매들로부터 1,4-다이옥산이 theta solvent로 선정되었고, cloud-point법을 통해 PTMSDPA/1,4-다이옥산(1,4-dioxane) 용액의 phase diagram이 도출되었다. Theta condition으로 농도 0.88×10<SUP>-2</SUP> M, 온도 51.6 ℃에서 임계점이 나타났다. 냉각과정에서 임계점 부근에서 급격한 형광증대현상이 나타났으며, 이는 비방사성 형광 감쇠를 초래하는 폴리머 사슬 내의 충돌소광 및 진동완화가 폴리머와 용매사이의 급작스러운 상분리에 의해 억제되었기 때문이다. 본 연구는 형광공액고분자에 열유도 상분리법을 적용하여 초고형광성 나노입자 및 다공막을 제조할 수 있는 잠정적인 방법을 제시하고 있다. Phase change and fluorescence properties of the polydiphenylacetylene derivative, poly[1-phenyl-2-(p-trimethysilyl) phenylacetylene] (PTMSDPA), were investigated according to the thermally induced phase separation (TIPS) method. 1,4-dioxane was selected as the theta solvent from solvents having solubility parameters similar to that of the polymer, and the phase diagram of the solution of PTMSDPA/1,4-dioxane was derived using the cloud-point method. A critical point appeared at a concentration of 0.88×10<SUP>-2</SUP> M and a temperature of 51.6 ℃ as the theta condition. During the cooling process, a significant fluorescence enhancement occurred near the critical point, because collision quenching and vibration relaxation in the polymer chain, which causes non-radiative emission decay, are restrained by the abrupt phase separation between the polymer and the solvent. This study provides a tentative method for producing highly fluorescent nanoparticles and microporous membranes by applying TIPS to fluorescent conjugated polymers.
-
진영재(Young-Jae Jin),오주희(Ju-Hee Oh),곽기섭(Giseop Kwak) 한국고분자학회 2016 폴리머 Vol.40 No.5
본 연구에서는 단량체로 diphenylacetylene 유도체(DPAmC18)를, 가교제로 2관능성 1,4-bis[phenylethynyl]benzene(PEB)를 사용하여, 신축성을 가지는 형광 공액고분자를 합성하였고 물성을 평가하였다. FTIR 분석을 통해 생성고분자들의 구성비를 확인하였으며, XRD, DSC, 자외가시흡광 및 형광방출 스펙트럼 분석을 통해 열역학적/구조적/광학적 특성을 비교 평가하였다. 고분자 내 PEB 함유량의 증가에 따라 단일중합체인 PDPAmC18의 열역학적, 구조적 특성이 점차적으로 변한 반면, 형광특성의 변화는 거의 없었다. 상온에서 UTM을 이용한 기계적 물성을 측 정한 결과, PEB의 함유량이 10%인 중합체는 70%~100%의 인장변형 범위에서 가장 가역적인 신축성을 보임과 동시에 가역적인 형광 및 편광형광 변화를 나타내었다. 이 결과는 이들 고분자의 형광장력센서로서의 응용가능성을 시사한다. Stretchable fluorescent conjugated polymers were synthesized by copolymerization of diphenylacetylene derivative (DPAmC18) and di-functional 1,4-bis[phenylethynyl]benzene (PEB) using as a monomer and a cross-linker, respectively, in different feed ratios and their properties were investigated. The compositional ratios of the polymers were confirmed by FTIR spectroscopy and their thermodynamic/structural/optical properties were evaluated and compared by XRD, DSC, UV-vis absorption and fluorescence (FL) emission spectroscopic analyses. The thermodynamic/structural feature of the homopolymer, PDPAmC18, varied gradually according to the amount of PEB in the polymers while the FL emission was almost not changed. As a result of UTM measurement at room temperature, the polymer having a 10% feed ratio of PEB showed the most reversible stretchability in a tensile strain range from 70% to 100% and, simultaneously, the FL and polarized FL emission were changed reversibly. These results suggest a potential application of our polymers using as a FL tension sensor.
-
용매열처리에 따른 PEDOT:PSS 암모니아 가스 감지막 특성 변화
노왕규 ( Wang Gyu Noh ),염세혁 ( Se-hyuk Yeom ),이왕훈 ( Wanghoon Lee ),신한재 ( Han Jae Shin ),계지원 ( Ji Won Kye ),곽기섭 ( Giseop Kwak ),김세현 ( Se Hyun Kim ),류시옥 ( Si Ok Ryu ),한동철 ( Dong Cheul Han ) 한국센서학회 2017 센서학회지 Vol.26 No.2
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively studied as the active material in ammonia gas sensor because of its fast response time, high conductivity and environmental stability. It is well known that a post annealing process for organic devices based on PEDOT:PSS significantly increases the device performance. In this study, we propose the solvent annealing of PEDOT:PSS and investigated its effects. As a results, post solvent annealing on PEDOT:PSS lead to the surface chemical and physical properties change. These changes result in improved conductivity of the PEDOT:PSS. In additional, ammonia sensitivity of solvent annealed PEDOT:PSS become higher than pristine polymer film. The enhancement is mainly caused by the depletion of gas barrier PSS and structural re-forming PEDOT networks. We believe that the post solvent annealing is a promising method to achieve highly sensitivity PEDOT:PSS films for applications in efficient, low-cost and flexible ammonia gas sensor.
-
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
