SPLAY ELASTICITY IN AN OLIGOMERIC LIQUID-CRYSTAL

A magnetically-induced Freedericksz transition was used in conjunction with capacitance techniques to determine the splay elastic constant of the 4, 4′-dialkoxyphenylbenzoate monomer ‘5OO5rsquo; and its dimer. As a function of reduced temperature in the nematic phase, it was found that of the dimer is only about 20 per cent larger than that of the monomer. Moreover, the values of versus reduced temperature, where is the scalar order parameter, are equal to within experimental noise. These results suggest that for short oligomers Meyer's entropic model for splay elasticity in polymer liquid crystals is not applicable. A lowest order correction to the entropic model is suggested, which partially accounts for excluded volume and dispersive effects. © 1990 Taylor & Francis Group, LLC.