Calorimetric and dielectric investigations of smectic liquid crystals with aerosil

Two strongly polar 4-(4-cyanobenzyloxy) benzylidene 4-n-alkylanilines were synthesized for the first time and mixed with the hydrophilic aerosil A 300. The compounds, showing a rich polymorphism, and the mixtures were investigated by calorimetric and dielectric methods. Phase transitions of first and second order were detected. Neither the phase transition temperatures nor dielectric relaxation times are strongly influenced by addition of aerosil up to 20%.