Azimuthal Anchoring Strength in Photopatterned Alignment of a Nematic

Autor: H. Nilanthi Padmini, Mojtaba Rajabi, Sergij V. Shiyanovskii, Oleg D. Lavrentovich
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Crystals, Vol 11, Iss 6, p 675 (2021)
Druh dokumentu: article
ISSN: 2073-4352
DOI: 10.3390/cryst11060675
Popis: Spatially-varying director fields have become an important part of research and development in liquid crystals. Characterization of the anchoring strength associated with a spatially-varying director is difficult, since the methods developed for a uniform alignment are seldom applicable. Here we characterize the strength of azimuthal surface anchoring produced by the photoalignment technique based on plasmonic metamsaks. The measurements used photopatterned arrays of topological point defects of strength +1 and −1 in thin layers of a nematic liquid crystal. The integer-strength defects split into pairs of half-integer defects with lower elastic energy. The separation distance between the split pair is limited by the azimuthal surface anchoring, which allows one to determine the strength of the latter. The strength of the azimuthal anchoring is proportional to the UV exposure time during the photoalignment of the azobenzene layer.
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