聚对苯二甲酸乙二酯荧光光谱的激发波长依赖性研究

聚对苯二甲酸乙二酯（PET）的荧光光谱已经得到了相当广泛和深入的研究,当激发光波长位于310～360nm时，可以观察到位于360～390nm范围的荧光发光,这部分荧光的来源有很多争议，至今未取得一致的看法，有作者认为，此处的荧光发光是PET链段上苯环之间的相互作用形成的基态二聚体（ground-state dimer）引起的发光；还有人认为这是苯环基团之间相互作用形成的激基缔合物的发光（excimeric emission）。

EXCITATION DEPENDENCE OF THE PHOTOLUMINESCENCE IN POLY(ETHYLENE TEREPHTHALATE)

The photoluminescence spectrum of poly(ethylene terephthalate) (PET) excited by light with wavelength in the reign from 260 to 360?nm was investigated.When the excitation wavelength was shorter than 300?nm,it was observed that the profile and structure of the photoluminescence spectrum of PET did not change with the increase of the excitation wavelength. When the excitation wavelength was longer than 300 nm,the wavelength dependence of the spectrum was observed. Excited in the reign from 300 nm to the value that was a little larger than the maximum excitation wavelength, there was only one main peak at 367 nm in the photoluminescence spectrum. However, with the continued increasing of the excitation wavelength, another peak appeared at 387 nm and its intensity increased accompanying with the decrease of the intensity of the peak at 367 nm. At last, the peak at 387 nm became the main peak and the peak at 367 nm changed to the second main peak. It was suggested that the photoluminescence of 367 nm and 387 nm would rather come from the excimeric emission and the ground state dimmer, respectively, than origin from the same emitting center.