Sidletskiy O. Short-range order effects in binary liquid crystalline systems and organic molecular crystals melts

. Object of study: the role of specific and non-specific interactions in short-range order in binary mixtures of liquid crystals and binary melts of organic molecular crystals. The aim of study: the determination of influence of peculiarities of intermolecular interactions on supramolecular ordering and properties of mesophase binary systems based on cyanobiphenyls and on melts of stilbene, naphthalene, diphenyl. The methods of study - electrophysical mesurements (temperature and concentration dependences of dielectric properties and charge trtransfer studies); spectrophotometry - for obtaining of absorption spectra (visible and UV-band) of isomolar series of binary systems solutions; differential scanning calorimetry (DSC) - to obtain the values of temperature and enthalpy of phase transitions; quantum-chemical calculations - to give ground the assumptions about peculiarities of intermolecular interactions, which were determined experimentally. Theoretical and practical results: Positive deviations from additive values for dielectric permittivity vs. concentration dependences both in the liquid crystalline and isotropic phases were observed in cyanobiphenyl - azomethine and cyanobiphenyl - stearic acid systems. Experimental evidence of the charge transfer complexes in melts of systems organic molecular crystal - chloranil have been obtained. Physical and chemical properties of these complexes are calculated. A model of the supramolecular structures formed is proposed accounting for specific and non-specific intermolecular interactions. Field of application: physics of liquid crystals, physics of molecular crystals, materials science