Abstract:Poly (3-dodecylthiophene) (P3DDT) has good solubility in the usual organic solvents. This characteristic determines that the preparation of P3DDT Nanofibers / wires is relatively difficult and its crystal structure is not easily controlled. In this work, P3DDT nanofibers were successfully prepared by low temperature annealing and self-nucleation method. The influence of self-nucleation temperature on the crystallinity and crystal modification of P3DDT nanofibers was investigated further. The results show that the homogeneous and high yield nanofibers can be obtained after the P3DDT solution is annealed at low temperature and then crystallized at room temperature. On this basis, the added self-nucleation step can further improve the crystallinity of nanofibers. The results of infrared spectra show that the samples obtained after low-temperature-annealing and self-nucleation take form II modification rather than the usual form I. Temperature dependent infrared test further reveals the transformation of P3DDT nanofibers from form II crystal to form I and then the phase change of the subsequent melting. The results of this work are expected to shed light on the preparation and polymorphic control of poly (3- alkylthiophene) (P3ATs) nanofibers / wires.