Calorimetric and dielectric investigations of smectic liquid crystals withaerosil

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 investi gated by calorimetric and dielectric methods. Phase transitions of first an d second order were detected. Neither the phase transition temperatures nor dielectric relaxation times are strongly influenced by addition of aerosil up to 20%.