Molecular dynamics of a main-chain liquid crystalline polyester below the crystalline to nematic phase transition

1997 ◽  
Vol 93 (8) ◽  
pp. 1605-1612 ◽  
Author(s):  
Valeria Arrighi ◽  
Julia S. Higgins
Keyword(s):  
Phase Transition ◽  
Molecular Dynamics ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Liquid Crystalline Polyester

Thermal transitions and molecular dynamics in main-chain liquid crystalline polyester/fullerene nanocomposites

2016 ◽  
Vol 38 ◽  
pp. E331-E341 ◽  
Author(s):  
Stefanos Koutsoumpis ◽  
Sotiria Kripotou ◽  
Natalia Nikonorova ◽  
Polycarpos Pissis
Keyword(s):  
Molecular Dynamics ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Thermal Transitions ◽  
Liquid Crystalline Polyester

Hydrogen bonding liquid crystalline benzoic acids with alkylthio groups: phase transition behavior and insights into the cybotactic nematic phase

2017 ◽  
Vol 41 (14) ◽  
pp. 6514-6522 ◽  
Author(s):  
Yuki Arakawa ◽  
Yukito Sasaki ◽  
Kazunobu Igawa ◽  
Hideto Tsuji
Keyword(s):  
Phase Transition ◽  
Hydrogen Bonding ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Benzoic Acids ◽  
Phase Transition Behavior ◽  
Transition Behavior

A novel class of hydrogen bonding liquid crystalline benzoic acids with alkylthio groups was established and their phase transition behavior was investigated in detail.

Polymorphous Structures and Their Phase Relationships in a Main-Chain/Side-Chain Liquid Crystalline Polyester

2002 ◽  
Vol 35 (3) ◽  
pp. 736-745 ◽  
Author(s):  
Jrjeng Ruan ◽  
Jason J. Ge ◽  
Anqiu Zhang ◽  
Jin Shi ◽  
Shy-Yeu Wang ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Main Chain ◽  
Side Chain ◽  
Liquid Crystalline Polyester ◽  
Phase Relationships

scholarly journals Order Parameters, Orientational Distribution Functions and Heliconical Tilt Angles of Oligomeric Liquid Crystals

2019 ◽  
Author(s):  
Richard Mandle ◽  
John W. Goodby
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Tilt Angle ◽  
Order Parameter ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Thermal Evolution ◽  
Order Parameters ◽  
Distribution Functions ◽  
Orientational Distribution

We compare the order parameters, orientational distribution functions (ODF) and heliconical tilt angles of the TB phase exhibited by a liquid-crystalline dimer (CB7CB) to a tetramer (O47) and hexamer (O67) by SAXS/WAXS. Following the N-TB phase transition we find that all order parameters decrease, and while 〈P2 〉 remains positive 〈P4 〉 becomes negative. For all three materials the order parameter 〈P6 〉 is near zero in both phases. The ODF is sugarloaf-like in the nematic phase and volcano-like in the TB phase, allowing us to estimate the heliconical tilt angle of each material and its thermal evolution. The heliconical tilt angle appears to be largely independent of the material studied despite the differing number of mesogenic units.

Phase Transition Behavior of Main Chain Nematic Liquid-Crystalline Polymers Based on 2-methyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone and 2-tert-butyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone

2012 ◽  
Vol 1403 ◽  
Author(s):  
Christain Melchert ◽  
M. Behl ◽  
A. Lendlein
Keyword(s):  
Phase Transition ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Phase Transition Behavior ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Crystalline Polymers ◽  
Transition Behavior ◽  
X Ray Scattering

ABSTRACTThe control of phase transition behavior in liquid crystalline polymers could enable potential application in the field of actuators and sensors by enabling a higher actuator performance of liquid crystalline elastomers (LCE). In this context the phase transition behavior of siloxane based liquid crystalline copolymers synthesized from 1,1,3,3-tetramethyldisiloxane, 2-methyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone (M-MeHq), and 2-tert-butyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone (M-tBHq) was explored. The selected monomers provided different thermal stabilities of the nematic phase, while the non-flexible siloxane spacer suppressed a smectic phase. The mesogenic properties were studied by means of differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and wide angle X-ray scattering (WAXS). With increasing fraction of M-MeHq the nematic phase of the copolymer was stabilized and a tailoring of relatively low TNI was achieved.

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