Orientational order parameter, S, in N-(p-n-ethoxy benzylidene)-p-n-alkoxy anilines, 2O.Om LC compounds

Abstract

The orientational order parameter, S, is estimated in N-(p-n-ethoxy benzylidene)-p-n-alkoxy anilines, 2O.Om liquid crystalline (LC) compounds with alkoxy chain number, m = 3, 4, and 6–10 using four different methods. The methods employed are (1) from birefringence, where ne and no are extraordinary and ordinary refractive indices, (2) from effective geometry parameter, αg, where α = no/ne, (3) from the Haller approximation (1 − T/TNIβ where β is obtained from method (1), and (4) the Maier and Saupe method from density. In the four methods proposed no field is chosen to explain the nematic liquid crystal and provides the S values obtained are identical to one another except in the case of 2O.O9 compound where the S values are higher when compared to the others. All the methods are explained in detail.