| Autor: |
Rajratan Basu, Lukas J. Atwood, George W. Sterling |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
|
| Zdroj: |
Crystals, Vol 10, Iss 2, p 123 (2020) |
| Druh dokumentu: |
article |
| ISSN: |
2073-4352 |
| DOI: |
10.3390/cryst10020123 |
| Popis: |
A small quantity of hexagonal boron nitride (h-BN) flakes is doped into a nematic liquid crystal (LC). The epitaxial interaction between the LC molecules and the h-BN flakes rising from the π−π electron stacking between the LC’s benzene rings and the h-BN’s honeycomb structure stabilizes pseudo-nematic domains surrounding the h-BN flakes. Electric field-dependent dielectric studies reveal that the LC-jacketed h-BN flakes follow the nematic director reorientation upon increasing the applied electric field. These anisotropic pseudo-nematic domains exist in the isotropic phase of the LC+h-BN system as well, and interact with the external electric field, giving rise to a nonzero dielectric anisotropy in the isotropic phase. Further investigations reveal that the presence of the h-BN flakes at a low concentration in the nematic LC enhances the elastic constants, reduces the rotation viscosity, and lowers the pre-tilt angle of the LC. However, the Fréedericksz threshold voltage stays mostly unaffected in the presence of the h-BN flakes. Additional studies show that the presence of the h-BN flakes enhances the effective polar anchoring strength in the cell. The enhanced polar anchoring strength and the reduced rotational viscosity result in faster electro-optic switching in the h-BN-doped LC cell. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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