The measurements of coexistence curves and light scattering for {xC6H5CN + (1 − x)CH3(CH2)16CH3} in the critical region

The coexistence curves and light scattering data for a critical solution of benzonitrile + octadecane have been reported. The critical exponents relating to the difference in density variables of two coexisting phases β, the correlation length ν, and the osmotic compressibility γ have been calculated. The experimental results of the coexistence curves have also been analyzed to examine the Wegner correction terms and the behavior of the diameter of the coexistence curves. The data analysis shows that the 3D-Ising behavior is valid in a temperature range close to the critical point. However in a wide temperature range the exponential values of ν and γ change with the temperature significantly, clearly exhibiting the critical crossover from the 3D-Ising universality class to the classical one.