Viscosity of liquid n -heptane by dynamic light scattering

The dynamic viscosity of liquid n-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 perlbrmcd 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 Ibr alkane viscosities, fronl which the deviations were below [ ",, over the whole range of relevant temperatures, the experiments may also be regarded its u sttcccsslʹtd test of the accuracy of the method.