Linearly polarized white fluorescence from shish-kebab type liquid crystalline poly(P-phenylenevinvlene)s with (P-phenylene)s as kebab

Abstract

Liquid crystalline (LC) polymers with a shish-kebab-type moiety on their cross-conjugated (p-phenylene)s-poly(pphenylenevinylene) s main chains were synthesized through Gilch polymerization in order to develop a kind of polymers available for linearly polarized white-light-emitting from single chain. In this system, the 2,5-bis(4′-alkoxyphenyl)benzene as the “kebabs” connects with poly(p-phenylenevinylene) (PPV) main chain backbone using its molecular gravity center and the PPV as the “shish” or “skewer” (the “shish-kebab”). The polymers possess desirable properties such as excellent solubility and liquid crystalline properties. To drop the “kebabs” of the 2,5-bis(4′-alkoxyphenyl)benzene into the orientation microgroove of aligned polyimide film, not only the “shish” of polymer main chain can be aligned by the virtue of orientation of “kebabs” but also the uniform cross-conjugated structure between the “kebabs” and “shish” can be broken. Then, the alignment of the polymer main chain showed yellow light emission and was also accompanied by orientation of the LC side chains showing blue light emission, this gave rise to a notable linearly polarized white fluorescence.