Photoinduced Increase in the Conjugation Length of Polymer Chains in Blue-Phase Polydiacetylene Films based on Diacetylene Alcohol Derivatives

Abstract

Photoinduced polymerization of Langmuir–Schaefer monolayers of four unsymmetrical hydroxyalkadiynyl N-arylcarbamate derivatives, prepared on the basis of diynes solutions with an extremely low concentration, was studied under prolonged UV irradiation. The kinetics of these diacetylene (DA) molecules films transition to the blue phase of polydiacetylenes (PDA) films, which is not characteristic of any other DA alcohol derivatives, has been studied by light absorption spectroscopy and scanning electron microscopy. The structure homogeneity of DA and PDA films was demonstrated. A continuous shift of the optical absorption band of each PDA film to the long-wavelength region of the spectrum during 60 min of UV light irradiation was found. That indicated an increase of the chains conjugation length in blue-phase PDA samples.