2007 Fiscal Year Final Research Report Summary
Nanosecond-Milisecond Dynamics of Phase Transition/Phase Separation of Thermo-Responsive Polymers.
| Project/Area Number |
18550002
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | Hokkaido University |
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Principal Investigator |
TSUBOI Yasuyuki Hokkaido University, Faculty of Science, Associate Professor (00283698)
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| Project Period (FY) |
2006 – 2007
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| Keywords | coil / globule / Stimuli-responsive polymer / poly(N-isopropylacrylamide) / poly(vinyl methyl ether) / gel / Volume phase transition / fluorescent probe |
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| Research Abstract |
We would like to demonstrate that laser is a powerful tool to explore chemistry of stimuli-responsive polymers. Main target materials of the present study are poly(N-isopropylacrylamide) (PNIPAM) and poly(vinyl methyl ether) (PVME) that are well known as representative thermo-responsive polymers. In aqueous solution, they exhibits phase transition from a coiled state to a globular state followed by phase separation in accordance to temperature elevation across the lower critical solution temperature. The present study falls into two categories. The first topic is (I) Dynamics of phase transition and phase separation as revealed by a laser T-jump technique. Time constants of the processes were determined with high accuracy and they were well correlated with molecular weight of the polymers. The second topic is (II) phase transition and phase separation induced by photon pressure of a focused laser beam. Optical micro-spectroscopy combined with laser-trapping technique was applied to the polymers and local structures of the polymer exerted with photon pressure were analyzed in details. Laser light would be an intriguing and novel stimulus to the polymers.
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