Thermal Fluctuations of Freely Suspended Smectic-A Films from Mesoscopic to Molecular Length Scales

1997 ◽  
Vol 79 (18) ◽  
pp. 3439-3442 ◽  
Author(s):  
E. A. L. Mol ◽  
G. C. L. Wong ◽  
J. M. Petit ◽  
F. Rieutord ◽  
W. H. de Jeu
Keyword(s):  
Thermal Fluctuations ◽  
Length Scales ◽  
Smectic A ◽  
Molecular Length ◽  
Freely Suspended

Smectic C to smectic A transition induced mechanically by the rupture of freely suspended liquid crystal films

Soft Matter ◽  
2017 ◽  
Vol 13 (17) ◽  
pp. 3199-3204 ◽  
Author(s):  
Torsten Trittel ◽  
Kirsten Harth ◽  
Ralf Stannarius
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Films ◽  
Smectic A ◽  
Smectic C ◽  
Crystal Films ◽  
Freely Suspended

scholarly journals Surface-enhanced ordering and layer-thinning transitions in freely suspended smectic-A films

1997 ◽  
Vol 55 (2) ◽  
pp. 2030-2033 ◽  
Author(s):  
Y. Martínez-Ratón ◽  
A. M. Somoza ◽  
L. Mederos ◽  
D. E. Sullivan
Keyword(s):  
Smectic A ◽  
Surface Enhanced ◽  
Freely Suspended

scholarly journals Fuel Cell Electrode Characterization Using Neutron Scattering

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1474 ◽  
Author(s):  
Olaf Holderer ◽  
Marcelo Carmo ◽  
Meital Shviro ◽  
Werner Lehnert ◽  
Yohei Noda ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Large Scale ◽  
Proton Mobility ◽  
Length Scales ◽  
Fuel Cell Electrode ◽  
Molecular Length ◽  
Energy Conversion And Storage ◽  
Ion Conducting ◽  
Cell Electrode ◽  
The Individual

Electrochemical energy conversion and storage is key for the use of regenerative energies at large scale. A thorough understanding of the individual components, such as the ion conducting membrane and the electrode layers, can be obtained with scattering techniques on atomic to molecular length scales. The largely heterogeneous electrode layers of High-Temperature Polymer Electrolyte Fuel Cells are studied in this work with small- and wide-angle neutron scattering at the same time with the iMATERIA diffractometer at the spallation neutron source at J-PARC, opening a view on structural properties on atomic to mesoscopic length scales. Recent results on the proton mobility from the same samples measured with backscattering spectroscopy are put into relation with the structural findings.

Measuring and modeling thermal fluctuations at nanometer length scales

2002 ◽  
Vol 65 (5) ◽  
Author(s):  
R. M. Ralich ◽  
R. D. Ramsier ◽  
D. D. Quinn ◽  
C. B. Clemons ◽  
G. W. Young
Keyword(s):  
Thermal Fluctuations ◽  
Length Scales

scholarly journals STATISTICAL PHYSICS OF ISOTROPIC-GENESIS NEMATIC ELASTOMERS: I. STRUCTURE AND CORRELATIONS AT HIGH TEMPERATURES

2013 ◽  
Vol 27 (17) ◽  
pp. 1330012 ◽  
Author(s):  
BING-SUI LU ◽  
FANGFU YE ◽  
XIANGJUN XING ◽  
PAUL M. GOLDBART
Keyword(s):  
High Temperatures ◽  
Liquid Crystalline ◽  
Landau Theory ◽  
Thermal Fluctuations ◽  
Cross Linking ◽  
Chain Model ◽  
Length Scales ◽  
Nematic Elastomers ◽  
Temperature State ◽  
The Cross

Isotropic-genesis nematic elastomers (IGNEs) are liquid crystalline polymers (LCPs) that have been randomly, permanently cross-linked in the high-temperature state so as to form an equilibrium random solid. Thus, instead of being free to diffuse throughout the entire volume, as they would be in the liquid state, the constituent LCPs in an IGNE are mobile only over a finite, segment specific, length-scale controlled by the density of cross-links. We address the effects that such network-induced localization have on the liquid–crystalline characteristics of an IGNE, as probed via measurements made at high temperatures. In contrast with the case of uncross-linked LCPs, for IGNEs these characteristics are determined not only by thermal fluctuations but also by the quenched disorder associated with the cross-link constraints. To study IGNEs, we consider a microscopic model of dimer nematogens in which the dimers interact via orientation-dependent excluded volume forces. The dimers are, furthermore, randomly, permanently cross-linked via short Hookean springs, the statistics of which we model by means of a Deam–Edwards type of distribution. We show that at length-scales larger than the size of the nematogens this approach leads to a recently proposed, phenomenological Landau theory of IGNEs [Lu et al., Phys. Rev. Lett.108, 257803 (2012)], and hence predicts a regime of short-ranged oscillatory spatial correlations in the nematic alignment, of both thermal and glassy types. In addition, we consider two alternative microscopic models of IGNEs: (i) a wormlike chain model of IGNEs that are formed via the cross-linking of side-chain LCPs; and (ii) a jointed chain model of IGNEs that are formed via the cross-linking of main-chain LCPs. At large length-scales, both of these models give rise to liquid–crystalline characteristics that are qualitatively in line with those predicted on the basis of the dimer-and-springs model, reflecting the fact that the three models inhabit a common universality class.

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