Pretilt angle control of liquid crystal molecules by photoaligned films of azobenzene-containing polyimide with a different content of side-chain

2008 ◽  
Vol 104 (11) ◽  
pp. 113528 ◽  
Author(s):  
Kiyoaki Usami ◽  
Kenji Sakamoto ◽  
Junichiro Yokota ◽  
Yoichi Uehara ◽  
Sukekatsu Ushioda
Polymer ◽  
2006 ◽  
Vol 47 (5) ◽  
pp. 1555-1562 ◽  
Author(s):  
Yoon Jung Lee ◽  
Jung Geun Choi ◽  
In-kak Song ◽  
Jae Min Oh ◽  
Mi Hye Yi

Author(s):  
Veronika S. Bezruchenko ◽  
Alexander A. Muravsky ◽  
Anatoli A. Murauski ◽  
Alexander I. Stankevich ◽  
Uladzimir V. Mahilny

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 736
Author(s):  
Kyutae Seo ◽  
Hyo Kang

We synthesized a series of polystyrene derivatives that were modified with precursors of liquid crystal (LC) molecules, such as 4-ethyloxyphenol (homopolymer PEOP and copolymer PEOP#; # = 20, 40, 60, and 80, where # indicates the molar fraction of 4-ethyloxyphenoxymethyl in the side chain), 4-n-butyloxyphenol (PBOP), 4-n-hexyloxyphenol (PHOP), and 4-n-octyloxyphenol (POOP), via polymer modification reaction to investigate the orientation of LC molecules on polymer films, exhibiting part of the LC molecular structure. LC molecules showed a stable and uniform vertical orientation in LC cells fabricated with polymers that have 4-ethyloxyphenoxymethyl in the range of 40–100 mol%. In addition, similar results were obtained in LC cells fabricated with homopolymers of PEOP, PBOP, PHOP, and POOP. The vertical orientation of LC molecules in LC cells fabricated with polymer films correlated to the surface energy of polymer films. For example, vertical LC orientation was observed when the total surface energies of the polymer films were lower than approximately 43.2 mJ/m2. Good alignment stabilities were observed at 150 °C and 20 J/cm2 of ultraviolet irradiation for LC cells fabricated with PEOP film.


Polymer ◽  
1991 ◽  
Vol 32 (8) ◽  
pp. 1347-1353 ◽  
Author(s):  
G.R. Mitchell ◽  
F.J. Davis ◽  
W. Guo ◽  
R. Cywinski

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2058
Author(s):  
Kyutae Seo ◽  
Hyo Kang

We synthesized a series of polystyrene derivatives modified with precursors of liquid crystal (LC) molecules via polymer modification reactions. Thereafter, the orientation of the LC molecules on the polymer films, which possess part of the corresponding LC molecular structure, was investigated systematically. The precursors and the corresponding derivatives used in this study include ethyl-p-hydroxybenzoate (homopolymer P2BO and copolymer P2BO#, where # indicates the molar fraction of ethylbenzoate-p-oxymethyl in the side chain (# = 20, 40, 60, and 80)), n-butyl-p-hydroxybenzoate (P4BO), n-hexyl-p-hydroxybenzoate (P6BO), and n-octyl-p-hydroxybenzoate (P8BO). A stable and uniform vertical orientation of LC molecules was observed in LC cells fabricated with P2BO#, with 40 mol% or more ethylbenzoate-p-oxymethyl side groups. In addition, the LC molecules were oriented vertically in LC cells fabricated with homopolymers of P2BO, P4BO, P6BO, and P8BO. The water contact angle on the polymer films can be associated with the vertical orientation of the LC molecules in the LC cells fabricated with the polymer films. For example, vertical LC orientation was observed when the water contact angle of the polymer films was greater than ~86°. Good orientation stability was observed at 150 °C and with 20 J/cm2 of UV irradiation for LC cells fabricated with the P2BO film.


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