scholarly journals Effect of Position and Structure of the Terminal Moieties in the Side Group on the Liquid Crystal Alignment Behavior of Polystyrene Derivatives

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2822
Author(s):  
DaEun Yang ◽  
Kyutae Seo ◽  
Hyo Kang
Keyword(s):  
Liquid Crystal ◽  
Surface Energy ◽  
Polymer Films ◽  
Side Group ◽  
Polymer Modification ◽  
Liquid Crystal Alignment ◽  
Tert Butyl ◽  
Tertiary Carbon ◽  
Phenyl Rings ◽  
Crystal Alignment

We synthesized a series of polystyrene derivatives containing various side groups, such as the 4-(tert-butyl)-phenoxymethyl, 3-(tert-butyl)-phenoxymethyl, 2-(tert-butyl)-phenoxymethyl, 4-cumyl-phenoxymethyl, and 4-trityl-phenoxymethyl groups, through a polymer modification reaction to examine the liquid crystal (LC) alignment of these derivatives. In general, the vertical LC alignment on polymer films can be affected by the position and structure of the terminal moiety of the polymer side group. For example, the LC cells fabricated with 4-(tert-butyl)-phenoxymethyl-substituted polystyrene having a tert-butyl moiety as a para-type attachment to the phenoxy groups of the polystyrene derivatives exhibited vertical LC alignment, whereas the LC cells prepared from 3-(tert-butyl)- and 2-(tert-butyl)-phenoxymethyl-substituted polystyrene films exhibited planar LC alignment. In addition, the LC cells fabricated from 4-cumyl- and 4-trityl-phenoxymethyl-substituted polystyrene films with additional phenyl rings in the side groups exhibited planar LC alignment, in contrast to the LC alignment of the (tert-butyl)-phenoxymethyl-substituted polystyrene series. The vertical LC orientation was well correlated with the surface energy of these polymer films. For example, vertical LC orientation, which mainly originates due to the nonpolar tertiary carbon moiety having bulky groups, was observed when the surface energy of the polymer was lower than 36.6 mJ/m2.

scholarly journals Vertical Orientation of Liquid Crystal on 4-n-Alkyloxyphenoxymethyl-Substituted Polystyrene Containing Liquid Crystal Precursor

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 736
Author(s):  
Kyutae Seo ◽  
Hyo Kang
Keyword(s):  
Molecular Structure ◽  
Liquid Crystal ◽  
Surface Energy ◽  
Polymer Films ◽  
Ultraviolet Irradiation ◽  
Molar Fraction ◽  
Side Chain ◽  
Polymer Modification ◽  
Vertical Orientation ◽  
Surface Energies

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.

Liquid crystal alignment behavior on sulfonated poly(arylene ether sulfone) films

RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64031-64036 ◽  
Author(s):  
Hyo Kang ◽  
Kihyun Kim ◽  
Daeseung Kang ◽  
Jong-Chan Lee
Keyword(s):  
Liquid Crystal ◽  
Polymer Films ◽  
Liquid Crystal Alignment ◽  
Monomer Ratio ◽  
Arylene Ether ◽  
Crystal Alignment ◽  
Sulfonated Poly

A series of sulfonated poly(arylene ether sulfone) (PAES#, # is the feed monomer ratio of 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone) derivatives were synthesized to investigate the liquid crystal (LC) alignment property of these polymer films.

scholarly journals Dual liquid crystal alignment configuration based on nanoparticle-doped polymer films

2011 ◽  
Vol 19 (12) ◽  
pp. 11825 ◽  
Author(s):  
Andy Ying-Guey Fuh ◽  
Chen-Yu Huang ◽  
Cheng-Kai Liu ◽  
Yuan-Di Chen ◽  
Ko-Ting Cheng
Keyword(s):  
Liquid Crystal ◽  
Polymer Films ◽  
Liquid Crystal Alignment ◽  
Crystal Alignment ◽  
Doped Polymer

scholarly journals Vertical Liquid Crystal Alignment of Comb-Like Alkyl Hydroxybenzoate-Substituted Polystyrene

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 281 ◽  
Author(s):  
Changha Ju ◽  
Shinwoo Kang ◽  
Taehyung Kim ◽  
Chanhyuk Park ◽  
Hyo Kang
Keyword(s):  
Liquid Crystal ◽  
Surface Energy ◽  
Polymer Film ◽  
Polymer Films ◽  
Molar Fraction ◽  
Side Chain ◽  
Alignment Layer ◽  
Dc Voltage ◽  
Alkyl Groups ◽  
Crystal Alignment

We investigated the liquid crystal (LC) alignment behaviors of butyl hydroxybenzoate-substituted polystyrene (PBHB#; # = 20, 40, 60, 80, and 100, where # indicates the molar fraction of butyl hydroxybenzoate in the side chain), methyl hydroxybenzoate-substituted polystyrene (PMHB100), and ethyl hydroxybenzoate-substituted polystyrene (PEHB100). Generally, LC cells made employing polymer films having longer alkyl groups in the side chain show vertical LC alignment. For instance, a LC cell fabricated with the PMHB100 film showed random planar LC alignment, while the LC cells made from the PEHB100 and PBHB100 films exhibited vertical LC alignment. Moreover, LC cells prepared from a polymer film having a higher molar content of butyl hydroxybenzoate in the side chain exhibited vertical LC alignment. The observed vertical LC alignment behaviors are closely related to the surface energy of these polymer films. For instance, vertical LC alignment was observed when the surface energy of the polymer film was less than ~43.86 mJ/m2, which could result from the nonpolar alkyl groups of the alkyl hydroxybenzoate moiety. The LC cell prepared from PBHB100 as the LC alignment layer showed good electro-optical characteristics such as voltage holding ratio, residual DC voltage, and alignment stability at 200 °C.

Electrically Aligned Photo-Polymer Films for Liquid Crystal Alignment

1999 ◽  
Vol 329 (1) ◽  
pp. 441-446 ◽  
Author(s):  
Mee Whi Kima ◽  
Abbas Rastegar ◽  
Irena Drevensek Olenik ◽  
Pieter De Witte ◽  
Mahn Won Kim ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Polymer Films ◽  
Liquid Crystal Alignment ◽  
Crystal Alignment
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