Fig. 4: POM and optical microscope images.

a–d, i–k POM images of R-M-(PyBO)₄; e–h, l–n Optical microscope images of R-M-(PyBO)₄; o Plot of spherulite diameters of R-M-(PyBO)₄ vs time (h) in air. All spin-coated films from toluene solution (40 mg/mL) on quartz plates (1 cm × 3 cm) (1000 N/s, 30 s).