Latticelike Smectic Liquid Crystal Phase in a Rigid-Rod Helical Polyisocyanide with Mesogenic Pendants

2011 ◽  
Vol 133 (24) ◽  
pp. 9156-9159 ◽  
Author(s):  
Takashi Kajitani ◽  
Hisanari Onouchi ◽  
Shin-ichiro Sakurai ◽  
Kanji Nagai ◽  
Kento Okoshi ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal ◽  
Rigid Rod

Interplay Between the Crystal and Liquid Crystalline Ordering of iPP and Carbon Nanotube Composites under Melt-Shear

2011 ◽  
Vol 1308 ◽  
Author(s):  
Georgi Georgiev ◽  
Michael B. McIntyre ◽  
Robert Judith ◽  
Erin A. Gombos ◽  
Peggy Cebe
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystalline ◽  
Smectic Phase ◽  
Crystal Phase ◽  
Sudden Increase ◽  
Two Dimensional ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal ◽  
Polarized Microscopy ◽  
Nanotube Composites

ABSTRACTCarbon nanotubes (CNTs) exhibit liquid crystalline order and their nematic director couples to the one of low molecular weight liquid crystals. Here we explore the interactions between CNTs and the smectic liquid crystal phase of a polymer and the possibility for a similar coupling in this system. Isotactic Polypropylene (iPP) and iPP/CNTs nanocomposites were made in solution with varying CNT concentrations and hot pressed into 50-100μm thick films. The pure iPP and iPP/CNT films were then sheared at one rotation per second in the melt state. Shearing continued as the temperature was decreased from 200°C to 145°C to induce a smectic liquid crystal phase. The sheared samples were analyzed using polarized optical microscopy, Two Dimensional Microscopic Transmission Ellipsometry (2D-MTE) and Two Dimensional Wide Angle X-Ray Scattering (2D-WAXS). During shearing we detected a sudden increase of birefringence at 151°C in the samples, higher than the iPP crystallization temperature, indicating liquid crystalline ordering. The samples were then crystallized at 135°C for 30 minutes. We measured anisotropic 2D-WAXS patterns of the samples that contained CNTs, indicating strong ordering of the crystals. Upon reheating, we measured birefringence at temperatures higher than the melting endotherm for the iPP crystals, using polarized microscopy, which indicates that some smectic order still persists in the samples, even after crystallization and complete melting of all crystals. Our results indicate that CNTs couple to the smectic phase of iPP, improve its order upon shearing and the crystals created after the formation of the oriented smectic phase are strongly aligned parallel to the direction of shearing.

Carrier Transport Properties in Highly Ordered Smectic Liquid Crystal Phase

2020 ◽  
Vol 140 (4) ◽  
pp. 253-258
Author(s):  
Takenori Nitta ◽  
Takayuki Usui ◽  
Hiroaki Iino ◽  
Akira Ohno ◽  
Jun-ichi Hanna
Keyword(s):  
Liquid Crystal ◽  
Transport Properties ◽  
Carrier Transport ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal ◽  
Carrier Transport Properties

Rigid-Rod And Segmented Rigid-Rod Polyimides: GEL/SOL And Liquid Crystalline Transitions, Fibers And Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Stephen Z. D. Cheng ◽  
Fred E. Arnold ◽  
Mark Eashoo ◽  
Song-Koo Lee ◽  
Steve L. C. Hsu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
High Performance ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Dielectric Constants ◽  
Lyotropic Liquid Crystal ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Initial Modulus ◽  
Rigid Rod

ABSTRACTOrgano-soluble rigid-rod and segmented rigid-rod polyimides and their copolyimides exhibit isotropic solutions in hot m-cresol, but form gels upon cooling. A lyotropic liquid crystal phase is observed below the gel/sol transition. Mechanical gel formation is caused by liquid-liquid phase separation, while the liquid crystal phase may be formed through a nucleation process after gelation. High performance fibers can be spun from the hot isotropic solutions using a dry-jet wet spinning method. After the fibers are drawn at high temperatures, they display tensile strength higher than 3.2 GPa and an initial modulus higher than 130 GPa. In particular, the fibers retain relatively high mechanical properties at elevated temperatures. Solution casted films exhibit very low thermal expansion coefficients and dielectric constants. Their structure, morphology and property relationships will also be discussed.

Uniform textures of smectic liquid-crystal phase formed by bent-core molecules

1998 ◽  
Vol 57 (6) ◽  
pp. 6737-6740 ◽  
Author(s):  
A. Jákli ◽  
S. Rauch ◽  
D. Lötzsch ◽  
G. Heppke
Keyword(s):  
Liquid Crystal ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal

Observation of a soft smectic liquid-crystal phase in a mixture showing V-shaped switching

2001 ◽  
Vol 63 (5) ◽  
Author(s):  
Seiji Shibahara ◽  
Jun Yamamoto ◽  
Yoichi Takanishi ◽  
Ken Ishikawa ◽  
Hiroshi Yokoyama ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal

Quasi-smectic liquid crystal phase of octane in contact with 2D MoS2

2020 ◽  
Vol 533 ◽  
pp. 147386
Author(s):  
Loukia Maritsa ◽  
Alfredo Bol ◽  
Santiago Aparicio
Keyword(s):  
Liquid Crystal ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal

scholarly journals Organization of the polarization splay modulated smectic liquid crystal phase by topographic confinement

2010 ◽  
Vol 107 (50) ◽  
pp. 21311-21315 ◽  
Author(s):  
D. Ki Yoon ◽  
R. Deb ◽  
D. Chen ◽  
E. Korblova ◽  
R. Shao ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Smectic Liquid Crystal
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