Abstract
Density as a function of temperature was measured in the nematic and isotropic phases of p-n-pentyl-p'-cyanobiphenyl (5CB). Similar measurements were made on six dilute solutions of the quasispherical solute Et4C (tetraethylmethane) in 5CB. The results were used (on their own and with previous results from visual studies) to obtain βN and β1, the moduli of the slopes of the nematic and isotropic boundary lines in the reduced NI transition temperature (T*) vs. solute mole fraction (x 2) diagrams. The results verify the compatibility of the density and visual methods and show that T* vs. x 2 plots can, for all practical purposes, be considered linear in the x 2 ranges studied.