Study of phase transition of ferroelectric polymers by use of molecular dynamics and x-ray diffraction

利用分子动力学和 X 射线衍射研究铁电聚合物的相变

• 批准号: 03455003
• 负责人: TAKAHASHI Nobuyuki
• 金额: $ 0.51万
• 依托单位: Hokkaido University of Education, Hakodate
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03455003/
• 关键词: molecular dynamics simulation; structural phase transition; ferroelectric polymers; dipole orientation; electrostatic interaction; antiferroelectric phase; paraelectric phase; poly(vinylidene fluoride); 分子動力学; 結晶構造; コンフォメ-ション; 双極子秩序

Molecular dynamics simulations of the ferroelectric phase (low temperature phase) and a hypothetical paraelectric phase (high temperature phase) of poly(vinylidene fluoride) (PVDF) have clarified the following results.(1) Control of macroscopic electric fields is necessary for the simulation of the ferroelectric phase of PVDF. The effects of the electric fields suggest that the electrostatic interaction stabilizes the ferroelectric phase of poly(vinylidene fluoride).(2) The ferroelectric phase is transformed into nonpolar structures in the medium without polarization. The transition between the nonpolar phase and the ferroelectric phase is observed at low temperatures and suggests a possibility of antiferroelectric phase.(3) The simulation of a nonpolar phase at high temperature shows a characteristic rotation and inversion motion of dipoles and the sliding diffusion of the molecular chain, It shows a possibility of the paraelectric phase.(4) A nonlinear lattice size dependence of the anisotropic stress is observed at a high temperature phase of PVDF. This phenomenon gives an explanation of the structural phase transition accompanied by the stretching of the chain length induced by the pressure.

铁电相的分子动力学模拟（低温相）和假设的（乙烯基氟化物）（PVDF）的假设副相（高温相）（高温相）（PVDF）阐明了以下结果。（1）对宏观电场的控制是PVDF的铁电相模拟所必需的。电场的作用表明，静电相互作用稳定了聚（乙烯基氟化物）的铁电相。（2）将铁电相转化为没有极化的培养基中的非极性结构。在低温下观察到非极性相和铁电相之间的过渡，并提出了抗逆火相相的可能性。（3）在高温下非极性相的仿真显示了偶极子的特征性旋转和反转运动，并显示了分子链的滑动范围，它显示了rATE阶段的可能性。在PVDF的高温阶段观察到各向异性应力。这种现象给出了结构相变的解释，并伴随着压力引起的链长的拉伸。

项目成果

Nobuyuki Takahashi: "Molecular dynanics simulation of structural instability and polarization fluctuation in ferroelectric poly(vinylidene fluoride):effects of a method of constant electric field" Proceedings of The Second International Conference on Comp

高桥伸行：“铁电聚偏二氟乙烯结构不稳定性和极化波动的分子动力学模拟：恒定电场方法的影响”第二届国际计算机科学会议论文集

Nobuyuki Takahashi: "Molecular dynamics calculations on ferroelectric polymers.VIII Effects of atomic radius on the ferroelectric-antiferroelectric phase transition" Rep.Prog.Polym.Phys.Japan. 35. 183-186 (1992)

Nobuyuki Takahashi：“铁电聚合物的分子动力学计算。VIII 原子半径对铁电-反铁电相变的影响”Rep.Prog.Polym.Phys.Japan。

Nobuyuki Takahashi: "Molecular dynamics simulation of structural instability and polarization fluctuation in ferroelectric poly(vinylidene fluoride):effects of a method of constant electric field" Procedings of The Second Internatinal Conference on Comput

高桥伸行：“铁电聚偏二氟乙烯结构不稳定性和极化波动的分子动力学模拟：恒定电场方法的影响”第二届国际计算机会议论文集

Nobuyuki Takahashi: "Molecular dynamics calculations on ferroelectric polymers. V Crystal structures and dielectric anisotropy of PVDF" Rep. Prog. Polym. Phys. Japan. 34. 255-258 (1991)

Nobuyuki Takahashi：“铁电聚合物的分子动力学计算。PVDF 的 V 晶体结构和介电各向异性”Rep. Prog。

Nobuyuki Takahashi: "Molecular dynamics calculations on ferroelectric polymers.8Effects of atomic radius on the ferroelectric-antiferroelectric phase transition" Rep.Prog.Polym.Phys.Japan. 35. 183-186 (1992)

Nobuyuki Takahashi：“铁电聚合物的分子动力学计算。8原子半径对铁电-反铁电相变的影响”Rep.Prog.Polym.Phys.Japan。