| 학회 |
한국고분자학회 |
| 학술대회 |
2004년 봄 (04/09 ~ 04/10, 고려대학교) |
| 권호 |
29권 1호, p.45 |
| 발표분야 |
특별 심포지엄 |
| 제목 |
Optically Switchable Dumbbell-Shaped ABA Triblock Copolymers |
| 초록 |
Hyperbranched PEK-co-PBZT-co-hyperbranched PEK ABA triblock copolymers (with idealized dumbbell shape) were prepared via the PPA/P2O5 polycondensation method, which we developed. All resulting polymers were soluble in strong organic acids as well as in common organic solvents. As such, they allowed us to study the absorption and emission behaviors of PBZT in both protonated and non-protonated state for the first time ever. The block copolymers absorbed almost identically at 441-442 nm in MSA solutions (protonated) regardless of the endgroups of A block (phenyl or CO2H terminated). The organo-soluble copolymers absorbed at 412-542 nm in NMP solutions (non-protonated), which are as much as 100 nm red-shifted compared to MSA solution (protonated). The emission maxima of block copolymers were also identical at 468 nm in MSA solutions (protonated). The copolymers emitted light at 574 and 576 nm in NMP solutions (non-protonated), which are also more than 100 nm red-shifted compared to MSA solution (protonated). Surprisingly, both absorption and emission wavelengths of solutions in common organic solvents were getting shorter as function of exposure time under UV or visible light. After approached equilibrium wavelength, the solutions were placed at dark and the absorption and emission wavelengths of solutions went back to original wavelengths. Kinetics of optical behaviors was reversible and also depended on solvent viscosities. Dynamic measurements of absorption and emission properties are to be discussed. |
| 저자 |
백종범1, Christopher B. Lyons2, Loon-Seng Tan3
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| 소속 |
1충북대, 2Southwestern Ohio Council for Higher Education, 3US Air Force Research Laboratory |
| 키워드 |
Block Copolymers; Optically Switchable; PBZT; Hyperbranched Polymers
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| E-Mail |
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