Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA.
Soft Matter. 2017 May 31;13(21):3894-3908. doi: 10.1039/c7sm00485k.
Alternating current (AC) electric fields effectively align poly(3-alkylthiophene) (P3AT) fibers during a one-dimensional crystallization process. Structural, mechanical and electrical properties have been probed using microscopy, small angle neutron scattering (SANS), atomic force microscopy (AFM), X-ray diffraction (XRD), rheology, UV-Vis spectroscopy, and dielectric spectroscopy. Optimum frequency and amplitudes were identified for specific P3AT concentrations and for variable solvent quality. Optical microscopy along with SANS and XRD demonstrate alignment persists over both micrometer and nanometer length scales. Small amplitude oscillatory shear rheology also showed that the shear modulus increased for aligned fibers. The structural changes were correlated to improvements in electric conductivity as probed by dielectric spectroscopy. XRD experiments performed with variable sample orientations also showed that the P3HT π-π stacking direction was aligned parallel to the direction of the fiber axis. Electric field alignment was also possible for other alkyl-thiophene polymers and for polymers with simple backbone repeat units.
交流（AC）电场在一维结晶过程中有效地使聚（3-烷基噻吩）（P3AT）纤维排列。使用显微镜、小角中子散射（SANS）、原子力显微镜（AFM）、X 射线衍射（XRD）、流变学、紫外-可见光谱和介电光谱研究了结构、力学和电学性质。针对特定的 P3AT 浓度和不同的溶剂质量，确定了最佳频率和幅度。光学显微镜、SANS 和 XRD 表明，在微米和纳米长度尺度上都能保持纤维的对齐。小振幅振荡剪切流变学也表明，对齐纤维的剪切模量增加。结构变化与介电光谱探测到的电导率的提高有关。通过对不同样品取向进行 XRD 实验，还表明 P3HT π-π 堆积方向与纤维轴的方向平行对齐。电场对齐对于其他烷基噻吩聚合物以及具有简单主链重复单元的聚合物也是可行的。
