Kasian N. Optical properties and phase states of liquid-crystalline systems with non-mesogenic biologically active dopants.

Object of investigation - prosess of photo- and thermostimulated transformation of biologically active substances in mesophase and its influence on liquid crystalline (LC) phase properties. The aim of investigation is to study the effects of non-mesogenic dopants subject to photo- and thermoisomerization on mesomorphic and optical properties of LC compositions. Methods of investigation: spectrophotometry, differential scanning calorimetry, polarizing microscopy. Theoretical and practical results, novelty: effects of vitamin and provitamin D on the phase state of LC systems was established, a method of UV registration based on the smectic A - cholesteric photoinduced phase transition was proposed and realized. Linear dependance of cholesteric pitch vs. UV irradiation time of systems containing provitamin D was established, selective sensitivity of such system to UVB and UVC bands was demonstrated. It was determined that LC order suppresses the thermotransformation process of chromenoacridine. Influenceof dopants of different classes - typical thermotropic mesogens, liotropic mesogens and related non-mesogenic compounds - on mesomorphic behavior of organic salts was studied. Application fields: dosimetry of biologically active UV radiation.