Competition between Liquid Crystalline Phase Symmetry and Microphase Morphology in a Chiral Smectic Liquid Crystalline−Isotropic Block Copolymer

2000 ◽  
Vol 33 (3) ◽  
pp. 649-651 ◽  
Author(s):  
Armin Schneider ◽  
Jean-Jacques Zanna ◽  
Masayuki Yamada ◽  
Heino Finkelmann ◽  
Ralf Thomann
Keyword(s):  
Block Copolymer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase ◽  
Phase Symmetry

Side Chain Liquid Crystalline Thermoplastic Elastomers for Actuator and Electromechanical Applications

2005 ◽  
Vol 889 ◽  
Author(s):  
Eric Verploegen ◽  
LaRuth C. McAfee ◽  
Lu Tian ◽  
Darren Verploegen ◽  
Paula T. Hammond
Keyword(s):  
Block Copolymer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Liquid Crystalline Phase ◽  
Transverse Orientation ◽  
Isotropic Liquid ◽  
Polymer Backbone ◽  
Spacer Length

ABSTRACTThe synthesis of a polystyrene-b-polyvinylmethylsiloxane-b-polystyrene diblock and triblock copolymer functionalized with liquid crystals exhibiting a smectic C* phase on the PVMS central block is described. The synthetic route is based on the anionic polymerization of styrene and trimethyltrivinylsiloxane monomers and the functionalization of resulting triblock copolymers. The resulting polymer can self assemble into a thermoplastic elastomer where the high Tg styrene blocks serve as physical crosslinks for a low Tg siloxane block. The presence of a smectic liquid crystalline phase and the block copolymer mesophase are observed across various temperature ranges depending on the length of the spacer connecting the liquid crystalline moiety to the polymer backbone. The influence of mechanical deformation upon the morphologies of the liquid crystalline and block copolymer mesophases was investigated. The interactions between the smectic LC and the block copolymer morphologies and their influence upon their respective orientations in response to shear fields are detailed. The parallel-transverse orientation of the hexagonally close packed (HCP) cylinders of the block copolymer morphology and the smectic liquid crystalline phase, respectively, was observed for melt fiber drawn samples. However, the transverse-perpendicular orientation was observed for liquid crystalline block copolymers that experienced oscillatory shear. The transverse orientation of HCP cylinders was observed while shearing took place above the smectic to isotropic transition temperature, indicating that the presence of an isotropic liquid crystalline phase alters the orientation of the block copolymer morphology. Additionally, it was found that the spacer length was a key factor in the clearing points for the smectic liquid crystalline phase, as well as significantly influencing the nanophase segregation of the block copolymer.

Controllable Morphology Formation of Gold Nano- and Micro-plates in Amphiphilic Block Copolymer-based Liquid Crystalline Phase

2004 ◽  
Vol 33 (6) ◽  
pp. 720-721 ◽  
Author(s):  
Luyan Wang ◽  
Xiao Chen ◽  
Jie Zhan ◽  
Zhenming Sui ◽  
Jikuan Zhao ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase ◽  
Amphiphilic Block Copolymer ◽  
Micro Plates

scholarly journals Electron transfer studies of a conventional redox probe in human sweat and saliva bio-mimicking conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Krishnaveni ◽  
V. Ganesh
Keyword(s):  
Electron Transfer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Redox Couple ◽  
Liquid Crystalline Phase ◽  
Transfer Reactions ◽  
Redox Probe ◽  
Human Sweat

AbstractModern day hospital treatments aim at developing electrochemical biosensors for early diagnosis of diseases using unconventional human bio-fluids like sweat and saliva by monitoring the electron transfer reactions of target analytes. Such kinds of health care diagnostics primarily avoid the usage of human blood and urine samples. In this context, here we have investigated the electron transfer reaction of a well-known and commonly used redox probe namely, potassium ferro/ferri cyanide by employing artificially simulated bio-mimics of human sweat and saliva as unconventional electrolytes. Typically, electron transfer characteristics of the redox couple, [Fe(CN)6]3−/4− are investigated using electrochemical techniques like cyclic voltammetry and electrochemical impedance spectroscopy. Many different kinetic parameters are determined and compared with the conventional system. In addition, such electron transfer reactions have also been studied using a lyotropic liquid crystalline phase comprising of Triton X-100 and water in which the aqueous phase is replaced with either human sweat or saliva bio-mimics. From these studies, we find out the electron transfer reaction of [Fe(CN)6]3−/4− redox couple is completely diffusion controlled on both Au and Pt disc shaped electrodes in presence of sweat and saliva bio-mimic solutions. Moreover, the reaction is partially blocked by the presence of lyotropic liquid crystalline phase consisting of sweat and saliva bio-mimics indicating the predominant charge transfer controlled process for the redox probe. However, the rate constant values associated with the electron transfer reaction are drastically reduced in presence of liquid crystalline phase. These studies are essentially carried out to assess the effect of sweat and saliva on the electrochemistry of Fe2+/3+ redox couple.

Liquid crystalline phase transitions in hexakis(4-(4′-heptyloxy)biphenoxy)cyclotriphosphazene

1995 ◽  
Vol 18 (5) ◽  
pp. 795-800 ◽  
Author(s):  
K. Moriya ◽  
H. Mizusaki ◽  
M. Kato ◽  
S. Yano ◽  
M. Kajiwara
Keyword(s):  
Phase Transitions ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase

scholarly journals Influence of applied electric fields on the positive magneto-LC effects observed in the ferroelectric liquid crystalline phase of a chiral nitroxide radical compound

Soft Matter ◽  
2013 ◽  
Vol 9 (18) ◽  
pp. 4687 ◽  
Author(s):  
Katsuaki Suzuki ◽  
Yoshiaki Uchida ◽  
Rui Tamura ◽  
Yohei Noda ◽  
Naohiko Ikuma ◽  
...  
Keyword(s):  
Electric Fields ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Nitroxide Radical ◽  
Liquid Crystalline Phase

Self-Assembly-Induced Supramolecular Hexagonal Columnar Liquid Crystalline Phase Using Laterally Attached Nonmesogenic Templates

2000 ◽  
Vol 33 (17) ◽  
pp. 6315-6320 ◽  
Author(s):  
Huilin Tu ◽  
Xinhua Wan ◽  
Yuxiang Liu ◽  
Xiaofang Chen ◽  
Dong Zhang ◽  
...  
Keyword(s):  
Crystalline Phase ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase ◽  
Hexagonal Columnar
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