where nDm, nD1, and nD2 are the refractive indices of the binary
mixture, 1,1′-bicyclohexyl, and alkylcycloalkane, respectively.
The ΔnD values, which show slightly positive, are listed in
Table S6 of the Supporting Information. The values of Δη
versus composition can also be fitted to the Redlich−Kister
type polynomial equation using eq 2, and σ can be calculated
with eq 3. The correlation parameters and standard deviations
are summarized in Table S7 of the Supporting Information.