Dilatometric study to estimate thermo dynamical parameters of two CBOnO.m liquid crystalline compounds

The specially designed pykanometre and dilatometer is used to measure the temperature variation of density of two liquid crystalline CBOnO.m compounds namely

1. α-(4-cyanobiphenyl-4 heptyloxy)-ω-4-n-alkylanilinebenzylidene-4oxy)decane (C1)
2. α-(4-cyanobiphenyl-4 decyloxy)-ω-4-n-alkylanilinebenzylidene-4oxy)decane (C2)

Using density and thermal expansion coefficient data the temperature dependence of number of thermo dynamical parameters are estimated for the above two compounds. The results reveal that all the parameter shows a characteristic change at phase transition. The results are discussed in the light of the literature data available for number of liquid crystalline compounds.