Dynamical heterogeneity measured for multi-layered thin polymer films

2016 Fiscal Year Final Research Report

• Project/Area Number: 25287108
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Biological physics/Chemical physics/Soft matter physics
• Research Institution: Ritsumeikan University
• Principal Investigator: Fukao Koji 立命館大学, 理工学部, 教授 (50189908)
• Co-Investigator(Kenkyū-buntansha): 貞包 浩一朗 立命館大学, 理工学部, 助教 (50585148)
• Research Collaborator: DIDIER LONG CNRS/Solvay, LPMA, ディレクター ; Paul Sotta CNRS/Solvay, LPMA, 主任研究員
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: ガラス転移 / 積層薄膜 / 誘電緩和 / 電極分極過程 / ポリメチルメタクリレート / ポリアミドランダム共重合体

Outline of Final Research Achievements

1. The glass transition temperature (Tg) was investigated during annealing above Tg for stacked thin films of poly(methyl methacrylate) (PMMA). The Tg of as-stacked PMMA thin films exhibits thin-film-like behavior, insofar as Tg is depressed and the dynamics of the α process are faster than those of the bulk system. Annealing at high temperature causes Tg to increase from the reduced value approaching those of the bulk.
2. We investigate the relaxation of thin films of a polyamide random copolymer. Two dielectric signals are observed at high temperatures, the α process and the electrode polarization (EP) process. The relaxation time and the dielectric relaxation strength of the EP process are described by a linear function of the film thickness d for large values of d. Furthermore, there is distinct deviation from this linear law for thickness smaller than a critical value, which suggests that there is an increase in the diffusion constant of the charge carriers for the EP process.

Free Research Field

ソフトマター物理学、高分子物理学