Solubilized poly(3-alkylthiophene)s are known to self-assemble into well-ordered supramolecular aggregates upon lowering the solvent quality. This supramolecular organization largely determines the optical and electronic properties of these polymers. However, despite numerous studies the exact mechanism and kinetics of the aggregation process and the role of external stimuli are still poorly understood. Classical characterization techniques such as electronic spectroscopy, dynamic light scattering, and diffraction-based techniques have not been able to provide a full understanding. Here we use second-harmonic scattering (SHS) and third-harmonic scattering (THS) techniques to investigate this supramolecular aggregation mechanism. Our results indicate that the actual supramolecular aggregation is preceded by the formation of structured polymer-solvent clusters consistent with a nonclassical crystallization pathway.

已知溶解的聚（3-烷基噻吩）在降低溶剂质量时会自组装成有序的超分子聚集体。这种超分子的组织在很大程度上决定了这些聚合物的光学和电子性质。然而，尽管进行了大量研究，但对聚集过程的确切机制和动力学以及外部刺激的作用仍知之甚少。诸如电子光谱，动态光散射和基于衍射的技术之类的经典表征技术无法提供全面的了解。在这里，我们使用二次谐波散射（SHS）和三次谐波散射（THS）技术来研究这种超分子聚集机制。