| Abstract
| - Langmuir films composed of mixtures of an amphiphilic polymer containing azobenzene (Az) side chain(6Azn-PVA, n being the spacer length) and a nematic liquid crystal (LC) molecule, 4‘-pentyl-4-cyanobiphenyl(5CB), were prepared at the air−water interface in an attempt to construct the interface model of the commandsurface system which performs the photoswitching of LC alignment. Surface pressure−area isotherms,visualization by Brewster angle microscopy (BAM) and atomic force microscopy (AFM), and UV−visibleabsorption spectroscopy revealed that the two components are homogeneously mixed at a molecular levelwithout lateral phase separation under proper conditions concerning the way of mixing, the mixing ratio, andthe spacer length of the side chain. Upon homogeneous co-spread mixing, both the Az side chain of 6Azn-PVA and the LC molecule were oriented highly perpendicular to the water surface, which was unavailablewith the individual component. This orientational induction can be ascribed to a mutual insertion of the tworod-shaped components attained in a cooperative fashion. The above structural features of the hybrid monolayerfulfill important criteria in modeling the interface region of the photoswitchable LC alignment layer. Effectsof changes in mixing ratio and the spacer length (n) on the film structure are also described.
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