The Experts below are selected from a list of 12204 Experts worldwide ranked by ideXlab platform
Takashi Kato - One of the best experts on this subject based on the ideXlab platform.
-
Liquid-crystalline behavior and ion transport properties of block-structured molecules containing a perfluorinated ethylene oxide moiety complexed with a lithium salt
Polymer Journal, 2018Co-Authors: Taira Onuma, Masafumi Yoshio, Kimiaki Kashiwagi, Shinya Tahara, Takashi KatoAbstract:A perfluorinated oligo (ethylene oxide) monoalkyl ether containing a terminal methyl carbonate has been developed for potential application as quasi-solid-state electrolytes for Li-ion batteries. The fluorinated block-structured molecule self-assembles to form nanosegregated bilayer structures, which can be used for anisotropic Li ion transport when complexed with a Li salt. The complex shows ionic conductivities on the order of 10^−^6 S cm^−^1 in the ordered Smectic Phase formed at ambient temperature. The liquid-crystalline behavior of fluorinated block-structured molecules and the ion transport properties of their complexes with a Li salt have been examined. The block-structured molecules comprise a perfluorinated oligo (ethylene oxide) moiety containing a terminal methyl carbonate or a terminal hydroxyl group and an octadecyl moiety. These molecules exhibit highly ordered Smectic Phases. The fluorinated molecule with a terminal methyl carbonate possesses an isotropization temperature lower than that of the analogous non-fluorinated molecule. The fluorinated molecule complexed with a Li salt shows ionic conductivities on the order of 10^−6 S cm^−1 in the Smectic Phase formed at ambient temperature, while conductivities on the order of 10^−5 S cm^−1 are observed in the isotropic Phase.
-
11 Liquid-Crystalline Catenanes and Rotaxanes
Handbook of Liquid Crystals, 2014Co-Authors: Junji Sakuda, Takuma Yasuda, Takashi KatoAbstract:This article has no abstract. Keywords: catenanes; rotaxanes; liquid crystals; Smectic Phase; nematic Phase; supramolecular chemistry
-
a thermoresponsive photoluminescent Smectic liquid crystal change of photoluminescent color on the Smectic Smectic Phase transition
Chemical Communications, 2009Co-Authors: Shogo Yamane, Yoshimitsu Sagara, Takashi KatoAbstract:An anthracene derivative having forklike side chains shows a change of photoluminescent color from green to light blue at the Smectic–Smectic Phase transition.
-
an electrochromic nanostructured liquid crystal consisting of π conjugated and ionic moieties
Journal of the American Chemical Society, 2008Co-Authors: Sanami Yazaki, Masahiro Funahashi, Takashi KatoAbstract:A new electrochromic molecule comprised of π-conjugated and ionic moieties has been designed and synthesized. It forms a nanosegregated Smectic Phase in which ion-conductive layers of imidazolium salts are located between hole transport layers of phenylterthiophene moieties. Electrochromism is observed in the bulk liquid crystal state of this compound without an electrolyte solution. In this nanosegregated Smectic Phase, an electrical double layer is formed rapidly at the electrode. Consequently holes are injected from the electrode, resulting in oxidation of the π-conjugated moieties.
-
anisotropic ion conduction in a unique Smectic Phase of self assembled amphiphilic ionic liquids
Chemical Communications, 2005Co-Authors: Tomohiro Mukai, Masafumi Yoshio, Takashi Kato, Masahiro Yoshizawa, Hiroyuki OhnoAbstract:Two types of thermotropic Smectic Phase and of anisotropic ion conduction were observed in an amphiphilic ionic liquid, N-ethyl-N′-dodecylimidazolium dodecyl sulfonate/lithium tetrafluoroborate mixture.
Giacomo Saielli - One of the best experts on this subject based on the ideXlab platform.
-
influence of the ion size on the stability of the Smectic Phase of ionic liquid crystals
Soft Matter, 2020Co-Authors: Wudi Cao, Beeran Senthilkumar, Valerio Causin, Vincent P Swamy, Yanting Wang, Giacomo SaielliAbstract:The thermotropic Phase behavior of ionic liquids and ionic liquid crystals based on novel N-alkyl-3-methylpyridinium halides, trihalides and dichloroiodates was experimentally studied by polarized optical spectroscopy (POM) and differential scanning calorimetry (DSC) as well as by molecular dynamics (MD) simulation. In the experiments, the existence and thermal range of stability of the Smectic Phase of these ionic liquid crystals are found to strongly depend on the volume ratio between the cation and anion, that is their relative size. Only compounds with a relatively large volume ratio of the cation to anion, i.e., those with longer cationic alkyl chains and monoatomic halide anions, have a stable Smectic A Phase. Both melting points and clearing points increase with such a ratio. The MD simulation results qualitatively agree very well with the experimental data and provide molecular details which can explain the experimentally observed phenomena: the stronger van der Waals interactions from the longer alkyl chains and the stronger electrostatic interactions from the smaller anions with a higher charge density increase the stability of both the crystal Phase and the Smectic Phase; this also prevents the ionic layers from easily mixing with the hydrophobic regions, a mechanism that ultimately leads to a nanosegregated isotropic liquid Phase.
-
distribution and dynamic properties of xenon dissolved in the ionic Smectic Phase of c16mim no3 md simulation and theoretical model
Journal of Physical Chemistry B, 2016Co-Authors: Diego Frezzato, Giacomo SaielliAbstract:We have investigated the structural and dynamic properties of Xe dissolved in the ionic liquid crystal (ILC) Phase of 1-hexadecyl-3-methylimidazolium nitrate using classical molecular dynamics (MD) simulations. Xe is found to be preferentially dissolved within the hydrophobic environment of the alkyl chains rather than in the ionic layers of the Smectic Phase. The structural parameters and the estimated local diffusion coefficients concerning the short-time motion of Xe are used to parametrize a theoretical model based on the Smoluchowski equation for the macroscopic dynamics across the Smectic layers, a feature which cannot be directly obtained from the relatively short MD simulations. This protocol represents an efficient combination of computational and theoretical tools to obtain information on slow processes concerning the permeability and diffusivity of the xenon in Smectic ILCs.
Athrra Abdlkadhem - One of the best experts on this subject based on the ideXlab platform.
-
Preparation and Study the behavior of the liquid Crystalline Phases of Two series of Schiff's Base Compounds and using mixture method to identify the Smectic Phase
Asian Journal of Research in Chemistry, 2015Co-Authors: Sajida. H. Ridha, Athrra AbdlkadhemAbstract:Two series were prepared4-(alokxy)-N-(4-(heptyloxybenzylidene) aniline (7BAn) and N-(4-alokxybenzylidene)-4-(heptyloxy aniline) (nBA7) the compounds have been identified spectrally (FT-IR, HNMR), and(elemental analysis CHN) the mesomorphic Phases were identified by polarized light microscope and measured transition temperatures for compounds in addition to the Differential Scanning Calorimeter (DSC) and when we draw transition temperatures against the number of Carbons atoms for each series it was found the odd-even effect of crystalline Phase to Smectic Phase then to nematic Phase then to isotropic Phase, and when comparing the liquid crystal behavior for two series it was found that the series (7BAn) all compound exhibit Smectic Phase in addition to the nematic Phase except compound (n = 4) did not show Smectic Phase, while the series (nBA7) only two compounds show Smectic Phase (n = 6,7) in addition to the nematic Phase.
D. Sheng - One of the best experts on this subject based on the ideXlab platform.
-
Photopolymerization of a Semifluorinated Difunctional Liquid Crystalline Monomer in a Smectic Phase
Macromolecules, 1996Co-Authors: Charles E. Hoyle, Lon J. Mathias, C. Jariwala, D. ShengAbstract:The photoinitiated polymerization of a semifluorinated difunctional monomer, which can exist in both a Smectic liquid crystalline Phase and an isotropic Phase, has been investigated as a function of temperature. Although the maximum rate attained for photoinitiated polymerization in the Smectic Phase is lower than for polymerization in the isotropic Phase, the polymer chain kinetic lifetime is markedly longer in the Smectic Phase, presumably due to a relatively large decrease in termination rate compared to propagation. The results also suggest that both termination and propagation rate processes are diffusion controlled. By conducting polymerization at a temperature corresponding to the Smectic Phase of the monomer, it is possible to “lock-in” the order of the Smectic Phase in the cross-linked network generated.
Satyendra Kumar - One of the best experts on this subject based on the ideXlab platform.
-
synthesis and characterization of poly pyridinium salt s with organic counterions exhibiting both thermotropic liquid crystalline and light emitting properties
Macromolecules, 2004Co-Authors: Pradip K. Bhowmik, James J Cebe, Ivan K Nedeltchev, Shinwoong Kang, Satyendra KumarAbstract:Two poly(pyridinium salt)s with bulky organic counterions (tosylate and triflimide) were synthesized by either the ring-transmutation polymerization reaction of 4,4'-(1,4-phenylene)bis(2,6-diphenylpyrylium tosylate) with 1,12-diaminododecane on heating in dimethyl sulfoxide (DMSO) at 145-150 °C for 24 h or the metathesis reaction of the corresponding tosylate polymer with lithium triflimide in a common organic solvent such as acetonitrile. Their polyelectrolyte behavior in DMSO was determined by solution viscosity measurements, and their chemical structures were determined by Fourier transform infrared and Fourier transform NMR spectroscopy. They were characterized for their thermotropic liquid-crystalline properties with a number of experimental techniques. Poly(pyridinium salt) with tosylate as a counterion had a crystal-to-Smectic Phase transition at 116 °C that persisted up to its decomposition temperature. The corresponding polymer with triflimide as a counterion had not only lower crystal-to-Smectic Phase transition at 80 °C but also a Smectic-to-isotropic transition at about 180 °C. Both of these transitions were well below its decomposition temperature. It had better thermal stability than that of the corresponding tosylate polymer. Their fluorescence property in solutions of tetrahydrofuran and methanol as well as in the solid state was also included in this study.
