Electric Birefringence Relaxation Spectroscopy of Electroactive Polymer Solutions

用He-Ne激光器或Ar离子激光器等可见光源测量含共轭电子的电活性聚合物溶液的电双折射弛豫是困难的，因为这类聚合物在可见光范围内通常具有较强的吸收带。在这项研究中，通过利用高功率半导体激光器作为近红外光源，我们已经开发了一种高精度，宽带电双折射弛豫光谱仪，使我们能够在很短的时间内检测到的聚合物的弛豫光谱的总轮廓。研究结果如下：1.研制了一种高稳定度、大功率半导体激光光源系统。将该光源与高速、高分辨率的瞬态存储器和个人计算机相结合，实现了高精度的实时电双折射弛豫光谱仪.利用该光谱仪测量了聚二乙炔和聚噻吩等典型电活性聚合物在良溶剂和不良溶剂中的电双折射弛豫光谱，并获得了聚合物构象的信息（棒状或无规卷曲）以及聚合物中的电极化机制（由定域载流子引起的永久偶极矩的取向极化或由非定域载流子引起的感应极化），换句话说，对聚合物中带电载流子的迁移率的影响。

It is difficult to measure the electric birefringence relaxation of solutions of electroactive polymers with conjugated electrons by using a visible light source such as a He-Ne laser or Ar ion laser, because such polymers usually have strong absorption bands in visible light range. In this study, by utilizing a high-power semiconductor laser as a near-infrared light source, we have developed a high-accuracy, broadband electric birefringence relaxation spectrometer which enables us to detect a total profile of relaxational spectra of the polymers in a very short time. The results obtained are as follows.1. A semiconductor laser light source system with high stability and high power has been developed. By combining this light source with a high-speed, high-resolution transient memory and a personal computer, we have realized a high-accuracy realtime electric birefringence relaxation spectrometer.2. By use of this spectrometer, we have measured the electric birefringence relaxation spectra of typical electroactive polymers such as polydiacetylene and polythiophene in good and poor solvents, and obtained information on the polymer conformation (rodlike or randomly coiled) as well as on the electric polarization mechanism in the polymers (orientational polarization of permanent dipole moment arising from localized carriers or induced polarization due to unlocalized carriers), in other words, on the mobility of charged carriers in the polymers.