Macroscopically aligned helical polyacetylene synthesized in magnetically oriented chiral nematic liquid crystal field

摘要

We have succeeded in synthesizing macroscopically aligned helical polyacetylene (H-PA) by using magnetically oriented chiral nematic liquid crystal (N*-LC.) with monodomain structure. The N*-LC. with monodomain structure was prepared by applying a magnetic field as an external perturbation to a N*-LC. with polydomain structure. Because of the positive anisotropy of the diamagnetic susceptibility of N*-LC., the helical axis of the N*-LC. was oriented perpendicular to the direction of the applied magnetic field. The monodomain N*-LC. enabled us to synthesize macroscopically aligned H-PA. The bundles of fibrils were aligned parallel to the direction of the magnetic field and perpendicular to the axis of the N*-LC. It is anticipated that the macroscopically aligned H-PA film might be available for novel organic electromagnetic materials and also for the promising precursor of aligned helical graphite by using the morphology-retaining carbonization method.