The formation of supramolecular aggregates of anthraquinone dye N,N 0 -(4-methylphenyl)-1,4-diaminoanthraquinone (AQ) is shown to be clearly manifested in temperature-dependent selective reflection spectra of cholesteric solvents containing AQ as a non-mesogenic dopant. Using cholesteric matrices of different chemical nature (based on cholesterol esters or nematics with chiral dopants), one can distinguish between interactions of a solvent with individual AQ molecules and AQ aggregates, as well as between the aggregation and precipitation of AQ. The calculated relative birefringence data demonstrate the effects of AQ aggregates on the optical anisotropy and the orientational order in the systems under study.
Liquid crystalline (LC) mixtures of cholesteryl oleyl carbonate (COC) and 4pentyl-4'-cyanobiphenyl (5CB), as well as dispersions of single-walled carbon nanotubes (NTs) in these mixtures, were studied by means of selective reflection measurements, differential scanning calorimetry (DSC) and optical microscopy. The relative mass of COC in a mixture X was varied between 0.4 and 1.0, the temperature range of measurements was between 284 K and 314 K, and concentration of NTs was fixed at 0.1 %. Two important anomalies were noted:(1) the cholesteric to smectic-A transition temperature increased on dilution of COC by non-smectogenic 5CB in the concentration range 0.8
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