| Autor: |
Slobodan Žumer, Ichiro Amimori, James N. Eakin, Gregor Skačej, Jun Qi, Gregory P. Crawford |
| Rok vydání: |
2004 |
| Předmět: |
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| Zdroj: |
Physical review. E, Statistical, nonlinear, and soft matter physics. 71(3 Pt 1) |
| ISSN: |
1539-3755 |
| Popis: |
We investigate orientational ordering in stretched polymer-dispersed liquid-crystal (PDLC) droplets using deuterium nuclear magnetic resonance, in the nematic and isotropic phases. In the latter case, we estimate the surface order parameter ${S}_{0}$ and the thickness of the interfacial layer from the temperature-independent surface ordering model for an elliptical cavity with a varying aspect ratio. A simple phenomenological model well describes the quadrupole splitting frequency of NMR spectra in the isotropic phase. The strain dependence of ${S}_{0}$ suggests that stretching-induced changes in the orientation of polymer chains in the PDLC matrix noticeably affect liquid-crystal surface anchoring. Experimental results are supported by simulated NMR spectra obtained as output from Monte Carlo simulations of paranematic ordering in ellipsoidal droplets based on the Lebwohl-Lasher lattice model. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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