Alignment by Langmuir/Schaefer Monolayers of Bent-Core Liquid Crystals

Abstract

Bulk alignment of liquid crystalline phases is achieved using self-organized thin films of bent-core mesogens transferred to a glass substrate by Inverse-Langmuir-Schaefer (ILS). We discuss the importance of the architecture of the aligning molecules (hydrophilic/hydrophobic balance for film stability as well as other structural factors) andshow the dependence of the density of the monolayer with the alignment induced by it. These results are compared with molecular simulations for further understanding of molecular packing and interfacial interactions.

Structural transitions and guest/host complexing of liquid crystal helical nanofilaments induced by nanoconfinement

“…According to some previous works, 5CB molecules could exhibit smectic-like high positional ordering very near the surface even above the T NI temperature (~60°C), when 5CB molecules were in contact with two antagonistic surface boundaries: one with the planar substrates and the other one with the homeotropic air boundary ( 26 – 28 ). Similar to this case, for the nanoconfined 5CB/NOBOW mixture, the anchoring condition of 5CB is planar on the AAO wall and homeotropic at the 5CB/NOBOW contact zone ( 29 ). Under this condition, we could expect a similar layering behavior from 5CB that is anchored to the NOBOW molecules at the HNF surfaces that partially formed 5CB/NOBOW smectic A complex at the interface ( Fig.…”

Vertical Alignment of Liquid Crystals Over a Functionalized Flexible Substrate

“…demonstrated reversible homeotropic to planar photochemical alignment controls of a nematic LC using photochromic layers comprised of LB films of side chain type azobenzene amphiphilic polymers 13 . E. K. Mann and co-workers have described the perpendicular alignment of a nematic phase exhibited by a bent-core molecule using LS monolayers of BC LCs 21 . In an another approach, K. H. Kim et al .…”

Structure formation in monolayers composed of hard bent-core molecules

“…Its role is limited to confine molecules in 2D (strong planar anchoring). Under these assumptions the corresponding V ext does not depend on molecular orientational degrees of freedom and, hence, can be disregarded in the expansion (5). The variable X represents the set describing the position r = (x, y) of the centre of mass of the particle and its orientations.…”

“…Its role is limited to confine molecules in 2D (strong planar anchoring). Under these assumptions the corresponding V ext does not depend on molecular orientational degrees of freedom and, hence, can be disregarded in the expansion (5).…”

“…Two-dimensional structures made by complicated macromolecules are recently of great interest due to their potential applications, mainly in photoelectronic and biosensor area [1][2][3][4][5][6][7][8]. In contrast to assemblies of spherical objects like, for instance, colloidal or nanosilica spheres, in case of anisotropic or irregularly shaped particles, there is a possibility to realize monolayers exhibiting very regular patterns which, next, can be utilized as a matrix capable to orient liquid crystal or to fabricate elements of electronic devices [5]. It has also turned out that the structure of a matrix built within a monolayer may influence the activity of biomolecules.…”