J-like liquid-crystalline and crystalline states of polyaniline revealed by thin, highly crystalline, and strongly oriented films

0431082 - ÚMCH 2015 RIV US eng J - Článek v odborném periodiku
Gospodinova, Natalia - Tomšík, Elena - Omelchenko, Olga
J-like liquid-crystalline and crystalline states of polyaniline revealed by thin, highly crystalline, and strongly oriented films.
Journal of Physical Chemistry B. Roč. 118, č. 29 (2014), s. 8901-8904. ISSN 1520-6106. E-ISSN 1520-5207
Grant CEP: GA ČR(CZ) GA13-00270S
Institucionální podpora: RVO:61389013
Klíčová slova: J-aggregates * organic semiconductors * polyaniline
Kód oboru RIV: CD - Makromolekulární chemie
Impakt faktor: 3.302, rok: 2014

Liquid-crystalline state of dyes can be easy distinguished from the crystalline one by the appearance of characteristic long-wavelength optical absorption, the so-called J-band. Similarly, long-wavelength absorption of polyaniline is assumed to be the signature of its J-like liquid-crystalline state. When water evaporates from polyaniline adsorbed on a glass support during polymerization, the long-wavelength maximum at about 800 nm disappears, and one at 570 nm appears, characteristic for highly crystalline and strongly oriented thin film. Reversible red shift of long-wavelength absorption upon water adsorption is a significant feature of these films. By analogy with dyes, it is attributed to water-promoted superficial formation of J-like mesophase. Such surprising properties of wet films as propagation of chemical reduction and enhanced exciton transport, reported by us recently, can also be considered as a signature of the J-like liquid-crystalline state of polyaniline.
Trvalý link: http://hdl.handle.net/11104/0235725