Various in situ measurement techniques have been applied to investigate changes in the three-dimensional structures and the properties of fully aromatic polymers (mainly aromatic polyimides: PIs) generated at very high pressures up to 8 GPa. In particular, significant changes occurred in the ordered structures, aggregation states, electronic structures, and intermolecular interactions in the repeating units of the PI molecular chains and were observed by applying pressure with a high-pressure optical cell (up to 0.4 GPa, ca. 4000 atm) or a diamond anvil cell (DAC, up to 8.0 GPa, ca. 80,000 atm). In addition, the structural changes in the PI molecular chain repeating units and interchain distances induced by the ultrahigh pressures were observed with wide-angle X-ray diffraction, and they were compared and contrasted with optical absorption, fluorescent and phosphorescent emission spectra, infrared absorption spectra, and refractive indexes observed under the same conditions. These findings obtained at very high pressures provide molecular design guidelines for new PI materials with novel optical, electronic, and thermal functionalities that are not easy to achieve under ambient conditions.

已应用各种原位测量技术来研究在高达 8 GPa 的非常高的压力下产生的全芳香族聚合物（主要是芳香族聚酰亚胺：PI）的三维结构和性质的变化。特别是，在 PI 分子链的重复单元中的有序结构、聚集状态、电子结构和分子间相互作用发生了显着变化，并且通过使用高压光学单元施加压力（高达 0.4 GPa，ca. 4000 atm）或金刚石压砧（DAC，高达 8.0 GPa，约 80,000 atm）。此外，用广角X射线衍射观察了超高压引起的PI分子链重复单元和链间距离的结构变化，并与光吸收进行了比较和对比，在相同条件下观察到的荧光和磷光发射光谱、红外吸收光谱和折射率。这些在非常高的压力下获得的发现为具有在环境条件下不容易实现的新颖光学、电子和热功能的新型 PI 材料提供了分子设计指南。