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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC POLYMER SCIENCE JAPAN  

The rotational isomeric state analysis of poly(ethylene terephthalate) (PET) was carried out by using parameters adjusted so as to reproduce the experimental results of H-1 NMR and dipole moment measurements on ethylene glycol dibenzoate. The central OC-CO bond of the ethyleneglycol unit prefers to be in the gauche form at lower temperatures, suggesting that the PET chains should contain many kink conformations in the amorphous state. In the following part, the nematic conformation of the same C-C bond was Studied by preparing a model compound which is capable of forming an enantiotropic nematic liquid crystalline (LC) phase. IR studies indicate that the trans fraction of the C-C bond increases from similar to 15% in the isotropic liquid to similar to 50% in the nematic LC state at the phase boundary. For this drastic change in the conformation at the transition, the C-C bond should be required to pay certain entropy penalty. These results are however compatible with the recent observations by SAXS and DPLS that the formation of nematic LC-like domains proceeds prior to the evolution of primary crystal nucleation during the cold-crystallization of PET. The PET chain is known to take the planar all-trans conformation in the crystalline state. Finally a possible mechanism leading to the nematic order in the amorphous PET is presented. Growth of the nematic LC-like domains in the amorphous phase may lead to a spinodal microphase separation, as suggested by Kaji et al.

DOI： 10.1295/polymj.PJ2007204

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Molecular dynamics (MD) simulations of 1,4-polybutadiene in bulk amorphous state were performed. To investigate motional coherency the relaxation rates for the collective and self motions, the collective and self relaxation rates, were evaluated for the short and long time regimes of the normalized intermediate scattering functions. The scattering vector dependence of the collective relaxation rates estimated for both fast and slow processes indicated a minimum at scattering vector q=1.3 angstrom(-1), corresponding to the position of a peak in the static structure factor. The self relaxation rates increased monotonously with q. A phenomenon known as de Gennes narrowing was reproduced well in the simulation and found to be originated from the inter-molecular correlation. The details of motional coherency and the distribution functions of relaxation time were evaluated. Keywords: amorphous; molecular dynamics; motional coherency and the distribution functions of relaxation time were evaluated.

DOI： 10.1002/masy.200750426

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Molecular dynamics simulations of 1,4-polybutadiene in bulk amorphous state were performed. Results were compared with the recent neutron spin-echo measurements. To investigate motional coherency the relaxation rates for the collective and self-motions, the collective and self-relaxation rates, were evaluated for the short and long time regimes of the normalized intermediate scattering functions. The scattering vector dependence of the collective relaxation rates estimated for both fast and slow processes indicated a minimum at scattering vector q = 1.5 angstrom(-1), corresponding to the position of a peak in the static structure factor. The self-relaxation rates increased monotonously with q. A phenomenon known as de Gennes narrowing was reproduced well in the simulation and found to be originated from the inter-molecular correlation. The collective relaxation rate evaluated for fast process appeared to modulate around a peak of q = 2.9 angstrom(-1), corresponding to the intra-molecular correlation. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2006.06.004

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PHYSICAL SOC JAPAN  

We performed thermal neutron spin echo measurements on a glass-forming polymer, deuterated polybutadiene (-[CD2-CD=CD-CD2](n)-; PB-d(6)), in a high Q range up to 3.5 angstrom(-1) covering the first and second peaks of the structure factor S(Q), and evaluated the decay rate Gamma(Q) of the coherent intermediate scattering function as a function of Q. In contrast to the previous experimental findings on the first peak of S(Q) at Q = 1.5 angstrom(-1), no 'de Gennes' type narrowing was observed on the second peak at Q = 2.9 angstrom(-1). This novel finding indicates that the narrowing is hidden by the distinct motions of the soft -CD2-CD2- and =CD-CD2- units and the self-motions of the rigid and soft units in the Q range around the second peak. The temperature dependence of the relaxation rate Gamma(Q) suggests that in the high Q range beyond the first peak of S(Q) the conformational changes in a deutrated PB chain are mainly observed.

DOI： 10.1143/JPSJ.74.3236

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

A modified form of the van der Waals expression for the attractive intermolecular potential E = - η/V-m has often been used to take account of the acentric character of the potential function, where V is the volume, η a mean-field parameter representing the strength of the interaction field, and m an empirical parameter, usually a constant in the range 1-2. In this article, we have attempted to examine the validity or limitation of this expression in terms of the relevant equation of state terms such as pressure, volume, temperature, and thermal pressure coefficient. The parameters m and η in the equation were estimated separately. A series of n-alkanes including polyethylene, polyoxyethylene, and a segmented dimer compound capable of forming a liquid crystal were investigated. Strictly speaking, the accuracy of the expression was found to be guaranteed only in a limited range of temperature and volume. An interesting behavior was found for m and η in the LC state. Importance of the analysis on anisotropic liquids such as LCs is emphasized. © 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2005.02.039

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：SPRINGER-VERLAG BERLIN  

Segmented chain molecules involving mesogenic units along the backbone chain, conventionally called mainchain liquid crystals, often exhibit an enatiotropic nematic liquid-crystalline phase over a certain temperature range between the crystal and the isotropic melt. The phase transitions involved are usually of first order. Spectroscopic analyses such as X-ray and neutron diffraction, IR and Raman absorption, and H-1 and H-2 NMR demonstrated that the orientational ordering of mesogenic cores in the mesophase are strongly coupled with the spatial arrangement of the spacer. While the orientation of the molecular axis (i.e., the whole molecule) varies as a function of temperature, the well-defined nematic conformation of the spacer remains almost unaltered over the entire range of the liquid-crystalline state. In these compounds, the conformational transition takes place in the order isotropic random coil <-> nematic conformation <-> extended crystalline form, or vice versa during the crystallization/melting process. In this article, we first present a brief summary of the entropy of fusion of chain molecules. In the second part, conformational entropy changes associated with the melting via a nematic phase, or the crystallization via a nematic mesophase, are reviewed. The experimental data on liquid-crystal transitions were mostly collected from studies on oligomeric compounds such as dimer and trimer mainchain liquid crystals with neat chemical structures. Finally it is suggested that further studies on the phase transition of chain molecules via a nernatic mesophase may provide some valuable information regarding the embryonic stage of the polymer crystallization mechanism.

DOI： 10.1007/b107177

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

To investigate helix-coil transition mechanisms, conformations of Glu(12)-Ala(12), EA, in aqueous solution have been studied in detail over the pH range from 2 to 8 and the temperature range from 20 to 60 degrees C using CD and NMR spectroscopy. The 750-MHz NMR spectra displayed excellent dispersion of the backbone amide proton signals, and permitted essentially complete sequence-specific resonance assignments. These assignments, together with short- and medium range nuclear Overhauser effect (NOE) constraints and coupling constants, enable us to analyze conformational characteristics of all the residues in the EA peptide individually. A combined use of CD and NMR techniques reveals that the EA peptide assumes a stable alpha-helix from Glu12 to Ala19 in 0. 1M NaCl solution at 20 degrees C above pH 7. The a-helix is getting longer as decreasing pH. Below pH 4, the peptide assumes the longest alpha-helix from Glu3 to Ala23. The important observation of the present study is that the helix- coil transition occurs stepwise, residue by residue, from both the Nand C-termini of the alpha-helix. No conformational equilibrium between the helical and random-coil states is detected for the residues in the central region of the a-helix. Quantitative analysis of temperature-induced helix-to-coil transitions at various pHs provides a pH-independent residual enthalpy change Delta H-r = 0.95 kcal res (-1). Similar values hove been reported for a 50-residue alanine-rich peptide (1.2 kcal res(-1)), poly-(L)-glutainate (1.1 kcal res(-1)), poly-(L)-lysine (1.1 kcal res(-) 1), and poly-(L)-alanine (0.86 kcal res(-1)). Those investigations, along with our present result, suggest that Delta H-r is mainly determined by the transformation of the backbone associated with the disruption of the intramolecular hydrogen bond. These results should increase our understanding of the helix-coil transition. (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/bip.20206

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

This is one of a series of studies on the reversal of the helix sense of polyaspartates originated from the pioneering work of Goodman and his associates in 1960s. Poly(beta-p-chlorobenzyl (L)-aspartate) (PClBLA) is one of the well-studied polyaspartate derivatives in both solution and the solid state. The chemical structure of PClBLA differs from those of poly(beta-benzyl (L)-aspartate) (PBLA) and poly(beta-phenethyl (L)-aspartate) (PPLA) only at the terminal of the relatively long side chain. PBLA takes a left-handed form (L) in conventional helicoidal solvents and does not exhibit any screw-sense inversion. In contrast to PBLA, both PClBLA and PPLA form a right-handed helix (R) in chlorinated alkane solvents and exhibits a reversal of a-helix sense at higher temperatures. Yet the transition behaviors in the presence of denaturant acid are quite different between these two polymers. While PPLA exhibits transitions such as R -> L -> coil by lowering temperature, PClBLA directly goes into the coil state without showing the reentrant L form. The cause of these phenomenological differences among these polymers has been investigated by constructing the phase diagram. (c) 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 80: 249-257,2005.

DOI： 10.1002/bip.20207

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DOI： 10.1002/masy.200390033

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/koron.60.181

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS LTD  

We synthesized three partially deuterated polymer samples, namely a poly(ethylene-alt-propylene) (EP) alternating copolymer, a poly(styrene-b-EP) diblock copolymer (SEP) and a poly(styrene-b-EP-b-styrene) triblock copolymer (SEPS). The H-2 spin-lattice relaxation time, T-1, of EP soft segments above their glass transition temperature was measured by solid-state H-2 NMR spectroscopy. It was found that the block copolymers had a fast and a slow T-1 component whereas EP copolymer had only a fast component. The fast T-1 components for SEP and SEPS are similar to the T-1 value of EP above ca 20degreesC. The slow T-1 component for SEP and SEPS exhibited a minimum at 60degreesC and approached the value of the fast component near the T-g of polystyrene. The motional behavior of the EP units for SEP is similar to that of SEPS over the entire range of temperature. Copyright (C) 2001 John Wiley Sons, Ltd.

DOI： 10.1002/mrc.985

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Molecular dynamics (MD) simulations of cis-1,4-polybutadiene in bulk amorphous state were performed to elucidate the origin of a fast relaxation process observed by quasielastic neutron scattering (QENS) measurements. The details of the torsional motion for each dihedral angle were investigated with the torsional auto- and cross-correlation functions for several temperatures in this study. Temperature dependence of the correlation between the torsional autocorrelation and cross-correlation functions is also evaluated. The origin of the fast process of cis-1,4-polybutadiene is found to be mainly the cooperative conformational transitions of two dihedral angles located at both sides of the CH2-CH2 bond when the bond is in the trans conformation. The cooperative conformational transitions exhibit even below the glass transition temperature of cis-1,4-polybutadiene. The cooperative motion appears at about 50 K below the glass transition temperature, corresponding to the Vogel-Fulcher temperature. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0032-3861(01)00629-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Molecular dynamics (MD) calculations of cis-1,4-polybutadiene in bulk amorphous phase were performed under constant pressure and constant temperature conditions. The static and dynamic properties were evaluated from the results of MD calculations. The obtained density and coefficient of thermal expansion are in good agreement with experimental data. The feature of the calculated static structure factor is similar to the observed one. Molecular motion is examined with mean square displacements and intermediate scattering functions. An onset of a new motion, which Corresponds to so-called fast process, was clearly observed in the temperature dependence of the mean square displacement above 100 K. The dynamic structure factors obtained by the Fourier transformation of the intermediate scattering functions are compared with those obtained from quasielastic neutron scattering measurements. The peaks corresponding to the elastic scattering and the low energy excitation at around 2 meV are reproduced in the dynamic structure factors. The excessive intensity observed in the dynamic structure factor, which corresponds to the fast process, is also reproduced above 140 K in our simulation. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0032-3861(01)00628-0

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DOI： 10.1295/polymj.34.450

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

A conventional method of estimating conformational entropy change at the melting point of polymers has been set forth in Mandelkern's book. The entropy separation according to this method involves a hypothetical assumption that the volume of the isotropic fluid may be compressed to that of the solid state without affecting the configurational part of the entropy of molecules. In this work, we have extensively examined the volume dependence of thermal pressure coefficient gamma = (deltaP/deltaT)(V) = (deltaS/deltaV)(T) of n-undecane. Molecular dynamic simulations were performed using the software package Insight II/Discover. In the standard calculation, a cubic box containing 30 n-undecane molecules was used under the conventional periodic boundary conditions. The experimental observations were well reproduced by the MD simulation performed as above, and accordingly the gamma vs specific volume (v(sp)) relations derived from the simulation are favorably compared with those obtained from the experimental PVT data. The gamma values remain quite insensitive to v(sp) over a wide range at given temperatures. Values of the trans fraction were found to decrease with an increase in temperature, while they tend to remain quite insensitive to pressure (0-200 MPa). It was concluded on this basis that the aforementioned treatment of the volume change at the phase transition seems to be supported by the present analysis.

DOI： 10.1021/ma001528r

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Various conformation-dependent properties of chain molecules have been successfully treated within the rotational isomeric state approximation. The conformation entropy is one of such properties which can be readily defined by the partition function, the sum of all possible configurations of the chain. Flexible polymers often exhibit crystallization and in some cases liquid-crystallization as well. In these first-order transitions, changes in the spatial arrangement of polymer chains are considered to be a major factor involved. In order to explicitly determine the conformational contribution to the melting entropy, the latent entropy observed under the isobaric condition must be corrected for the volume change. The entropy separation involves a hypothetical assumption that the volume of the isotropic fluid may be compressed to that of the solid state without affecting the configurational part of the entropy of molecules. Finally thermodynamic significance of the conformation entropy in these transitions is emphasized on the basis of the critical studies of the entropy-volume relation of chain molecules in the liquid state.

DOI： 10.1002/1521-3900(200109)174:1<383::AID-MASY383>3.0.CO;2-C

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DOI： 10.1103/PhysRevB.64.144202

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DOI： 10.1295/polymj.33.825

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DOI： 10.1295/polymj.31.728

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Polyoxyethylene (POE) is known to be highly flexible, a variety of spatial configurations being permitted. Like many other conventional polymers, the conformation of the POE chain can be treated within the framework of the rotational isomeric state (RIS) approximation using a limited number of RIS parameters. An unambiguous assignment of numerical values to statistical weights such as sigma and omega has not been achieved for the chain occurring under various conditions: sigma for the rotation around the C-C bond and omega for the so-called second-order interaction taking place between the methylene group and the oxygen atom separated by four bonds. In this work, we have attempted to demonstrate the role of these two parameters in determining the conformation-dependent properties of the POE chain. Various RIS parameter sets reported in literature have been compared with a model calculation, in which sigma and omega are varied over a wide range, the other parameters being kept invariant. A comprehensive analysis provides a rational explanation for the long lasting question why so many RIS parameter sets effectively reproduce the conformational characteristics of the identical polymer molecule. Finally, it is emphasised that a critical assessment of omega and/or sigma is required to establish an unambiguous RIS description of the POE chain. (C) 1998 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S1089-3156(98)00046-4

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

The gas-phase NMR analysis of 5-methoxy-1,3-dioxanes was carried out. The conformational energies estimated from the observed coupling constant data were compared with the results of ab initio MO calculations using d95 + (2df,p) basis set at the MP2 level. While the energy difference between the axial-out and equatorial-out forms was in a reasonable agreement, the 1,5 interaction energy between the methoxy methyl and the ring oxygens was not in accord.

DOI： 10.1016/S0022-2860(96)09621-4

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DOI： 10.1002/(SICI)1097-0282(1997)43:6<405::AID-BIP2>3.0.CO;2-Z

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

The binding properties of trivalent ions to polyacrylate and its low molecular weight analogs (monomer, dimer, and trimer) were investigated in dilute aqueous solution (10(-2)-10(-3) M) using Tb3+ ion as a fluorescent probe. The fluorescence intensity and lifetime of the Tb3+ ion depend directly on the number of water molecules bound to their inner coordination sphere. The more efficiently ligands coordinate to Tb3+ ion, the more water molecules are expelled and, consequently, the greater the fluorescence intensity and lifetime observed. Lifetime measurements in H2O and D2O showed that the number of water molecules coordinated to the Tb3+ ion are 6.5, 6.1, 4.9, and 3.6 for monomer, dimer, trimer model compounds, and polyacrylate, respectively. The viscosities of Tb3+-polyacrylate complexes were measured in the presence of a large excess of sodium bromide. Viscosities (eta(sp)/c) of the polyacrylate solutions follow Huggins' equation, and on addition of Tb3+ ion, the intrinsic viscosities decrease abruptly from 700 to 40 mL/g. The mean end-to-end distances, [r(2)]1/2, for polyacrylate in Tb3+-polymer complexes were calculated using the Flory-Fox equation and were found to be reduced from 125 to 48 nm on addition of Tb3+. These results indicate that of the nine water molecules coordinated to Tb3+ ion in aqueous solution, five to six are replaced with carboxylate groups attached to the polymer chain wrapped around the Tb3+.

DOI： 10.1021/ma960251l

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ma951026r

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/polymj.28.41

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/koron.53.628

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Conformation of 1,3-dimethoxypropane has been studied in the gas phase (approximately 120-180 degrees C). Vicinal coupling constants (3)J(HH) and (3)J(CH) determined by H-1 and C-13 NMR were analysed within the rotational isomeric state approximation. The trans and gauche couplings required in this analysis were set equal to J(G) = 2.8 Hz and J(T) = 13.7 Hz for H-1-C-C-H-1, and J(G) = 2.0 Hz and J(T) + J'(G) = 16.0 Hz for C-13-O-C-H-1. The conformational energy parameters of the chain were conventionally defined as E sigma and E rho for the gauche state around the CH2-CH2 and OCH2 bond, respectively, and E omega for the repulsive second-order interaction (g(+/-)g(-/+)) for the OCH2-CH2-CH2O fragment. The experimental values of the coupling constants were found to be reproduced by a variety of combinations of E sigma and E omega, E rho being kept at 1.03 kcal mol(-1). Adoption of E omega = 1.97 kcal mol(-1) as calculated by a molecular mechanics method, led to E sigma = -0.84 kcal mol(-1). Alternatively, by setting E sigma = -0.58 kcal mol(-1) as calculated, E omega = 0.40 kcal mol(-1). Assuming E omega &gt; 1 kcal mol(-1) for the gas phase, a value of E sigma from -0.7 to approximately -0.9 kcal mol(-1) was proposed. The conformation, and thus conformational energies, varied quite sensitively with the polarity of the medium. The results were compared with those observed in solution.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

A molecular dynamics simulation of bulk atactic polystyrene was performed, and the result was analyzed in detail to evaluate the intramolecular and intermolecular short range orders present. In this work the analysis was performed only on the results obtained from the united atom model, since, as was shown in the previous two publications, it gives much better agreement with experiment than the all atom model. Most of the study was performed with a system containing a single 80-monomer molecule, but some study was also made with a system containing two 40-monomer molecules. The short range order was examined by evaluating the radial distribution functions and orientational order parameters of pairs of aliphatic backbone segments and of phenyl group centers. In the case of intramolecular phenyl pairs, these quantities were evaluated individually according to the monomeric distance along the chain by which the two phenyls are separated. The conformation of the molecule was examined by evaluating the population distribution of backbone bond torsional;angles in meso and racemic diads. The result resembles the conformational energy maps previously prepared by others, but some differences were also noted. The most prominent feature in the intermolecular correlation is the strong tendency for the phenyl groups to have a separation distance of about 6 Angstrom. A detailed analysis was given to define the relative orientation that the pair of phenyls adopt at this separation. Intermolecular pairs of backbone segments were found to be oriented mostly randomly at separation distances larger than 6 Angstrom.

DOI： 10.1021/ma00112a028

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/j100017a031

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

RIS analysis of the deuterium quadrupolar splitting data was performed for alpha,omega-bis[(4,4'-cyanobiphenylyl)oxy]alkane dimer liquid crystals having -O(CH2)(n)O- flexible spacers (n = 9 (CBA-9) and n = 10 (CBA-10)) between the 4,4'-cyanobiphenylyl ends according to the scheme previously established. The analysis indicates that most of the conformers involved in the range 0 &lt; psi(1),psi(2) &lt; 45 degrees adopt spatial configurations reasonably consistent with the nematic arrangement of mesogenic cores in both dimer LC systems, where psi(1), and psi(2) denote the inclination angles of the terminal mesogenic cores with respect to the molecular axis. The conformational entropy changes at the crystal-nematic (CN) and nematic-isotropic (NI) interphases estimated on this basis are as follows: CBA-9, Delta S-en(conf) = 59.6, Delta S-ni(conf) = 13.3; CBA-10, Delta S-ni(conf) = 64.2, Delta S-ni(conf) = 15.6 (J mol(-1) K-1 units). The values of the entropies Delta S-tr(conf) thus derived were compared with the constant-volume transition entropies (Delta S-tr)(v) determined by the PVT measurements reported in the accompanying paper: CBA-9, (Delta S-cn)(v) = 53.9, (Delta S-ni)(v) = 7.9; CBA-10, (Delta S-cn)(v) = 62.4, (Delta S-ni)(v)) = 13.3 (J mol(-1) K-1 units). In view of the uncertainties involved in the estimation of the entropies both in theory and in experiments, the correspondence is quite favorable. The conformation of the spacer undoubtedly plays an important role in determining the phase behaviors of these main chain liquid crystals. It is pointed out that the discrepancy between the calculation and experiment may be further improved by considering other contributions such as (1) the entropy changes due to the orientation of the anisotropic molecules in the liquid crystalline state and (2) the possibility of the entropy loss during the compression to achieve constant-volume transitions. It is concluded that the observed increase in the quadrupolar and dipolar splittings with decreasing temperature arises mainly from the variation of the order parameter of the molecular axis.

DOI： 10.1021/ma00105a012

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

The magnetic susceptibilities of some ether-type liquid-crystalline polymers such as -[PhOC-(O)PhO(CH2)nOPhC(O)OPhO(CH2)nO]x-(Ether-PLC-n) with n = 9 and 10 have been measured by a SQUID magnetometer. Variations of DELTA-chi at the isotropic to nematic transition were found to occur more gradually as compared with those observed for the dimer liquid crystals. The DELTA-chi values estimated for the stable nematic state were analyzed according to the RIS scheme developed in the previous work. The order parameters of the mesogenic core axis S(M) were elucidated for the nematic conformation derived independently from the H-2 NMR analysis. The same treatment has been extended to include ester-type main-chain liquid crystals such as -[Ph(CH3)N(O)NPh(CH3)OOC(CH2)(n)COO]x-(Ester-PLC-n) with n = 7 and 10, for which experimental data are available from Esnault et al.'s work. For both Ether- and and Ester-PLCs, the values of S(M) estimated from SQUID were found to be reasonably consistent with those obtained by the other measurements.

DOI： 10.1021/ma00010a056

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ma00220a015

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DOI： 10.1021/ma00197a018

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

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会議種別：ポスター発表  

researchmap

researchmap

会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

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会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

researchmap

会議種別：ポスター発表  

researchmap

researchmap

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