| Autor: |
Madsen, Louis A., Dingemans, Theo J., Poon, Chi-Duen, Samulski, Edward T. |
| Předmět: |
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| Zdroj: |
Liquid Crystals; Oct2020, Vol. 47 Issue 13, p2027-2042, 16p |
| Abstrakt: |
Numerous theories of molecular ordering in the nematic phase exist that attempt to incorporate the features of weak attractions, excluded volume (aspect ratio), and rigid and non-rigid segments, as well as assess entropic and enthalpic effects. Para-quinquephenyl represents a model rodlike molecule, but study of this liquid crystal presents challenges and surprises given the high temperature of the nematic phase. We present NMR experiments throughout the nematic range on two specifically deuterium-labelled quinquephenyl isotopomers, which we combine with high fidelity molecular dynamics simulations to explore and quantify various aspects of orientational order. The striking agreement between experiment and simulation provides new insights into the role of molecular flexibility and correlations (clustering, director fluctuations) on observed order parameters. We compare several nematic theories with our observations and discuss implications for further theoretical understanding. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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