Artículo
Orientational transitions in a nematic liquid crystal confined by competing surfaces
Autor/es | Rull Fernández, Luis Felipe
Rodríguez Ponce, Inmaculada Romero Enrique, José Manuel |
Departamento | Universidad de Sevilla. Departamento Física Atómica, Molecular y Nuclear |
Fecha de publicación | 2001 |
Fecha de depósito | 2017-09-13 |
Publicado en |
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Resumen | The effect of confinement on the orientational structure of a nematic liquid crystal model has been investigated by using a version of density-functional theory. We have focused on the case of a nematic confined by opposing ... The effect of confinement on the orientational structure of a nematic liquid crystal model has been investigated by using a version of density-functional theory. We have focused on the case of a nematic confined by opposing flat surfaces, in slab geometry (slit pore), which favor planar molecular alignment (parallel to the surface) and homeotropic alignment (perpendicular to the surface), respectively. The spatial dependence of the tilt angle of the director with respect to the surface normal has been studied, as well as the tensorial order parameter describing the molecular order around the director. For a pore of given width, we find that, for weak surface fields, the alignment of the nematic director is perpendicular to the surface in a region next to the surface favoring homeotropic alignment, and parallel along the rest of the pore, with a sharp interface separating these regions (S phase). For strong surface fields, the director is distorted uniformly, the tilt angle exhibiting a linear dependence on the distance normal to the surface (L phase). Our calculations reveal the existence of a first-order transition between the two director configurations, which is driven by changes in the surface field strength, and also by changes in the pore width. In the latter case the transition occurs, for a given surface field, between the S phase for narrow pores and the L phase for wider pores. A link between the L−S transition and the anchoring transition observed for the semi-infinite case is proposed. |
Agencias financiadoras | Dirección General de Investigación Científica y Técnica (DGICYT). España Junta de Andalucía |
Identificador del proyecto | PB97-0712
FQM-205 |
Cita | Rull Fernández, L.F., Rodríguez Ponce, I. y Romero Enrique, J.M. (2001). Orientational transitions in a nematic liquid crystal confined by competing surfaces. Physical Review E covering statistical, nonlinear, biological, and soft matter physics, 64 (5), 1-18. |
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