Mutual diffusion coefficients of (isooctane + n-heptane) and (n-decane + n-heptane) from 288.15 K to 318.15 K

The mutual diffusion coefficients of (isooctane + n-heptane) and (n-decane + n-heptane) binary solutions were measured over the mass fraction from 0.05 to 0.95 at the pressure of 0.101 MPa, and at temperatures T  = 288.15 K, 298.15 K, 308.15 K and 318.15 K, respectively. The expanded relative uncertainty of the digital holographic interferometry employed in this measurement was estimated to be 2.6% with the confidence level of 0.95 ( k  = 2). The influences of temperature and composition on the mutual diffusion coefficients were discussed. Moreover, the semi-empirical correlations of mutual diffusion coefficients for (isooctane + n-heptane) and (n-decane + n-heptane) binary mixtures were given by fitting the experimental results as a function of temperature and mass fraction. The absolute average of relative deviations of the correlations are 0.72% for (isooctane + n-heptane) and 0.54% for (n-decane + n-heptane), respectively.