| Project/Area Number |
13650953
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
高分子構造・物性(含繊維)
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
KANAYA Toshiji Kyoto Univ., Inst. For Chem. Res., Prof., 化学研究所, 教授 (20152788)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TASAKI Seiji Kyoto Univ., Institute for Research Reactor, Assistant, 原子炉実験所, 助手 (40197348)
海老沢 徹 京都大学, 原子炉実験所, 助教授 (30027453)
|
|---|
| Project Period (FY) |
2001 – 2002
|
| Project Status |
Completed (Fiscal Year 2002)
|
| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2002: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2001: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
|---|
| Keywords | Glass transition / Boson peak / Fast process / Confinement / Thin film / Neutron scattering / 中性子散乱 / 速い過程 / 非エルゴード性 / 長距離密度揺らぎ / ガス透過性 / 光散乱 |
|---|
| Research Abstract |
We have studied annealing effects of polymer thin films on glass transition using neutron and X-ray reflectivity. It was found that the previously reported negative expansivity of polymer thin films below about 20 nm is caused by unrelaxed structure due to lack of annealing. This structural relaxation occurs within one or two hours above the glass transition temperature. In addition to the relaxation process, we also found a very slow relaxation process above the glass transition temperature. The relaxation time was estimated at 423K to be 30 - 50h. One of the candidates of this slow motion is "sliding motion" proposed by de Gennes. The dynamics of polymer thin fims were directly studied using inelastic neutron scattering and for the first time we observed boson peak of the films 100 and 40 nm thick.
We also studied motional slowing down of glass-forming polybutadiene near the glass transition temperature in a very wide Q range. In this experiment for the first time we found that the Q-dependence of relaxation time does now show a maximum at the second peak position of structure factor S(Q).
|
