The Determination of the Frank Elastic Constant for Twist Deformation of 4′-n-pentyl-4-cyanobiphenyl (5CB) Using a Conoscope

The Frank elastic constant for twist deformation k 22, has been determined as a function of temperature for 5CB and compared with values cited in literature. The results, together with the values of the elastic constants for splay, k 11, and bend, k 33, which have been measured recently by Bradshaw et al. and the values for k 11/k 22, and k 33/k22 as found by Hara et al. suggest that the values of Karat and Madhusudana (corrected by Bunning et al.) are somewhat too low.