Viscosity of liquidn-heptane by dynamic light scattering

The dynamic viscosity of liquidn-heptane was measured in the temperature range 293–353 K by dynamic light scattering employing a newly designed optical setup. Commercial stearyl-coated silica particles were used as a seed, where a calibration of particle sizes to obtain absolute viscosity values was performed in other alkanes. The measurements included experimental runs at various particle concentrations and scattering vectors and in both a heating and a cooling cycle with a total standard deviation of 0.8–0.9%. As established reference values exist for alkane viscosities, from which the deviations were below 1% over the whole range of relevant temperatures, the experiments may also be regarded as a successful test of the accuracy of the method.