Incorporation in Langmuir and Langmuir-Blodgett films of symmetric fluorine substituted bent-core liquid crystals: Morphological and optical properties
Por:
García-Vázquez P., Morales-Saavedra O.G., Pelzl G., Banuelos, JG, Carreón-Castro M.P.
Publicada:
1 ene 2009
Resumen:
Molecular mono- and multilayer films of a symmetric fluorine substituted bent-core liquid crystalline (LC) compound with hydrocarbon end-chains were prepared by the Langmuir and Langmuir-Blodgett (LB) technique. Langmuir films were characterized by surface pressure isotherms and Brewster angle microscopy. Likewise LB-films deposited onto amorphous glass substrates were characterized by ultraviolet-visible spectroscopy, the optical second harmonic generation technique and atomic force microscopy (AFM). Results show optimal non-centrosymmetric Z-type LB-film deposition for moderate number of layers (n<20); thereafter, an apparent collapse of the Z-type structure occurs, giving rise to a decrease of the nonlinear optical (NLO) properties, AFM, NLO and linear optical measurements suggest a uniform molecular coverage on the glass substrates and anisotropic orientational distribution; where, according to NLO-experimental data, the LC-bent-shaped molecules are preferably aligned toward the di
Filiaciones:
García-Vázquez P.:
Univ Nacl Autonoma Mexico, ICN, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico
Morales-Saavedra O.G.:
Univ Nacl Autonoma Mexico, CCADET, Ctr Ciencias Aplicadas & Desarrollo Tecnol, Lab Nonlinear Opt, Mexico City 04510, DF, Mexico
Pelzl G.:
Institut fur Physikalisches-Chemie, Martin Luther University, Halle-Wittenberg, Mühlpforte 1, D-06108 Halle, Germany
Banuelos, JG:
Univ Nacl Autonoma Mexico, CCADET, Ctr Ciencias Aplicadas & Desarrollo Tecnol, Lab Nonlinear Opt, Mexico City 04510, DF, Mexico
Carreón-Castro M.P.:
Univ Nacl Autonoma Mexico, ICN, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico
|