Variations in Aggregation Structures and Fluorescence Properties of a Semialiphatic Fluorinated Polyimide Induced by Very High Pressure
Variations in Aggregation Structures and Fluorescence Properties of a Semialiphatic Fluorinated Polyimide Induced by Very High Pressure
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DOI：
10.1021/ma300497a
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发表时间：
2012-06
期刊：
影响因子：
5.5
通讯作者：
K. Takizawa;J. Wakita;K. Sekiguchi;S. Ando
中科院分区：
文献类型：
--
作者：
K. Takizawa;J. Wakita;K. Sekiguchi;S. Ando
利用同步辐射广角X射线衍射（WAXD）和荧光光谱研究了半脂族含氟10 FEDA/DCHM（聚（4，4 ′-二氨基环己基甲烷-1，4-双（3，4-二羧基三氟苯氧基）四氟苯酰亚胺）聚酰亚胺（PI）在高压下的聚集态结构和光学性质的变化.在220 °C下酰亚胺化的PI膜的荧光强度通过施加高达IGPa的压力而显著降低，这应该是由于链间自由体积的明显降低，如通过对应于分子间有序的WAXD峰的d-间距值的降低所指示的。相比之下，在300 °C下酰亚胺化的PI膜（其表现出比在大气压下在220 °C下酰亚胺化的PI膜更弱的荧光）在低于IGPa下表现出小得多的荧光强度降低。这种压力依赖性的差异清楚地反映了PI链堆积形成的程度。
Variations in the molecular aggregation structures and optical properties of a semialiphatic fluorinated 10FEDA/DCHM (poly(4,4′-diaminocyclohexylmethane 1,4-bis(3,4-dicarboxytrifluorophenoxy) tetrafluorobenzeneimide) polyimide (PI), which exhibits strong cyan fluorescence, were examined under very high pressure up to 8 GPa using synchrotron wide-angle X-ray diffraction (WAXD) and fluorescence spectroscopy. The fluorescence intensity of a PI film imidized at 220 °C was significantly reduced by applying pressure up to 1 GPa, which should be due to an appreciable reduction in interchain free volume, as indicated by a decrease in the d-spacing values of WAXD peaks which correspond to intermolecular ordering. In contrast, a PI film imidized at 300 °C, which exhibited weaker fluorescence than that imidized at 220 °C at atmospheric pressure, demonstrated a much smaller reduction in fluorescence intensity below 1 GPa. Such differences in pressure dependence clearly reflect the degrees of PI chain packing formed a...