Fig. 3.

Macroscopic helical chirality generation in the stripe. a Photographs of the left-handed helical ribbons with different feature size of helicity under different Φ_iPrOH. By introducing iPrOH into THF, the PANI:s-CSA macro stripe shrunk into left-handed helical ribbon step-by-step. Scale bar corresponds 0.5 mm. b Feature size of helicity p (helical pitch), d (diameter of the cylindrical helix), and proportional relation p/d of the helical ribbons decreased with increasing Φ_iPrOH. The black lines are theoretical calculating values of the feature size of helicity. c g-factor, and d the corresponding CD of the PANI:ѕ-CSA and PANI:ʀ-CSA ribbons measured in the co-solvent with different Φ_iPrOH