Frustrated molecular packing in highly ordered smectic phase of side-chain liquid crystalline polymer with rigid polyacetylene backbone.
Using poly(5-{[(4'-heptoxy-4-biphenylyl)carbonyl]oxy}-1-pentyne) as an example, we demonstrate the incorporative accommodation of the rigid polyacetylene backbones and the mesogenic pendants, which leads to a highly ordered smectic (Sm) phase with a frustrated structure. The polymer exhibits a recognizable sheetlike molecular shape due to its rigid backbone and relatively short spacer (three methylene units), and the building block of the liquid crystalline (LC) phase is the whole molecule. In the LC phase, five layers of the molecules stack as a smectic A (SmA) block, and adjacent SmA blocks glide halfway of the molecular width from one to another. In scanning tunneling microscopy (STM) experiments, the STM tip scrape is found to generate a regular nanopattern with periodic electron conductivity, of which the spacing is determined by the side-chain length.
Ye
Chun
C
Key Laboratory of Polymer Chemistry and Physics of Ministry of Education and Department of Polymer Science and Engineering, College of Chemistry, Peking University, Beijing 100871, China.
Xu
Guoqiang
G
Yu
Zhen-Qiang
ZQ
Lam
Jacky W Y
JW
Jang
Jee Hwan
JH
Peng
Hai-Lin
HL
Tu
Ying-Feng
YF
Liu
Zhong-Fan
ZF
Jeong
Kwang-Un
KU
Cheng
Stephen Z D
SZ
Chen
Er-Qiang
EQ
Tang
Ben Zhong
BZ