Influence of the molecular structure of thermotropic liquid crystals on their ability to form monolayers at interface

Characterization of Some Fluorinated Mesogens for Application in Liquid Crystal Displays

“…All substances were used without further purification; their phase transition temperatures in the bulk, determined on the basis of textures observed by means of polarizing microscope equipped with a hot stage are given in Table 1. The data for liquid crystal 8OCFPB, 8OCPFB and 5DBF3 are in agreement with the data given in the literature [7,8]. Most of the liquid crystals under investigation have only a nematic (N) phase between the solid and isotropic phases.…”

“…It is seen that the addition of the liquid crystal to AA changes the shape of p-A isotherm. For mixed Langmuir films the plateau region, characteristic for many thermotropic liquid crystals of rod-like shaped molecules [7,21,22], appears. The appearance of the plateau is thus indicative of incorporation of the liquid crystal molecules in a monolayer.…”

“…The characterization of both kinds of films of these two liquid crystals is described in [7]. None of the investigated liquid crystals with the negative dielectric anisotropy (even 5DBF3 which possess terminal polar fluorine atom) can produce compressible and stable monolayer on the water surface.…”

“…During the symmetrical compression of the monolayer at a barriers motion speed of 5 mm=min., the surface pressure p was measured. Further experimental details about Langmuir film creation are given elsewhere [7,12]. LB films were deposited on polished quartz plates (35 Â 10 Â 1 mm 3 ) with a rate of 5 mm=min by using vertical dipping method.…”

Formation of net-like patterns of gold nanoparticles in liquid crystal matrix at the air–water interface

“…Pressure-induced layering transitions of 8CB have been already intensively studied by means of: ellipsometry (Xue et al 1992), Brewster angle microscopy (BAM) (de Mul and Mann 1994, 1998; Friedenberg et al 1994; Modlińska et al 2009), surface potential measurements (Schmitz and Gruler 1995), and optical second harmonic generation (SHG) (Guyot-Sionnest et al 1986). The SHG technique was also used to confirm spontaneous organization of 8CB molecules evaporated onto a solid substrate into multilayer stacks (Olenik et al 2003).…”