PA6 and PA7 with ferroelectric liquid crystalline (FLC) functional moieties (Goto
et al. 2004; Suda and Akagi 2008; Akagi 2009). The mono-LCPAs bearing FLC
moieties exhibit a characteristic chiral smectic CÃ phase (S C Ã), which has the ability
to quickly respond to an electric field. Hsu et al. extended the concept of macroscopic alignment to chiral saccharide-containing PA8 (Ho and Hsu 2009). The
helical twist morphological structure of PA8 can be aligned on a polyimide rubbed
glass substrate to form two-dimensional ordered helical patterns. In addition, Okoshi
et al. synthesized optically active main chain type mono-LCPAs having a poly
(phenylacetylene) (PPA) main chain structure and D- or L-alanine moieties (PA9)
(Okoshi et al. 2005). The rigid PPA main chain, which has bulky phenyl group and
the intramolecular hydrogen bonding between the amide groups in the neighboring
side chains, can exhibit cholesteric phases in concentrated solutions. The development of these mono-LCPAs led us to extend the use of LC functionality to disubstituted PAs where the fluorescence of the di-PAs can be combined with liquid
crystallinity to gain novel functionalities, such as linearly and circularly polarized
luminescence.
Macroscopic Alignment and Linearly Polarized Luminescence
of Di-substituted LC Polyacetylene Derivatives
Over the past few years, various functional di-substituted polyacetylene derivatives
were developed. Masuda et al. developed gas permeable di-PA films (Masuda et al.
1988; Sakaguchi et al. 2008) and investigated di-PAs with photoelectronic properties
(Shiotsuki et al. 2011). Hsu et al. reported the electroluminescence (EL) of novel
Scheme 2 Structures of
conducting mono-substituted
LCPA derivatives
12 Liquid Crystalline Conjugated Polymers with Optoelectronic Functions
347
et al. 2004; Suda and Akagi 2008; Akagi 2009). The mono-LCPAs bearing FLC
moieties exhibit a characteristic chiral smectic CÃ phase (S C Ã), which has the ability
to quickly respond to an electric field. Hsu et al. extended the concept of macroscopic alignment to chiral saccharide-containing PA8 (Ho and Hsu 2009). The
helical twist morphological structure of PA8 can be aligned on a polyimide rubbed
glass substrate to form two-dimensional ordered helical patterns. In addition, Okoshi
et al. synthesized optically active main chain type mono-LCPAs having a poly
(phenylacetylene) (PPA) main chain structure and D- or L-alanine moieties (PA9)
(Okoshi et al. 2005). The rigid PPA main chain, which has bulky phenyl group and
the intramolecular hydrogen bonding between the amide groups in the neighboring
side chains, can exhibit cholesteric phases in concentrated solutions. The development of these mono-LCPAs led us to extend the use of LC functionality to disubstituted PAs where the fluorescence of the di-PAs can be combined with liquid
crystallinity to gain novel functionalities, such as linearly and circularly polarized
luminescence.
Macroscopic Alignment and Linearly Polarized Luminescence
of Di-substituted LC Polyacetylene Derivatives
Over the past few years, various functional di-substituted polyacetylene derivatives
were developed. Masuda et al. developed gas permeable di-PA films (Masuda et al.
1988; Sakaguchi et al. 2008) and investigated di-PAs with photoelectronic properties
(Shiotsuki et al. 2011). Hsu et al. reported the electroluminescence (EL) of novel
Scheme 2 Structures of
conducting mono-substituted
LCPA derivatives
12 Liquid Crystalline Conjugated Polymers with Optoelectronic Functions
347