THERMOPHORESIS OF AEROSOLS - A REVIEW

The modern theory of thermophoresis was developed in the linear approximation with respect to small Knudsen numbers, the zero approximation corresponding to the Epstein result. To compare experiment with the theory it requires measuring the dependence of the thermophoresis velocity or the thermophoresis force versus Kn. These results will have to be compared with the theory within the range of the applicability of the letter, i.e. at Kn << 1. This condition is replaced by a more rigorous one for high heat conductive aerosols. An analysis of experimental data indicates that none of the measurements of thermophoresis for high heat conductive aerosols satisfy the requirement which is necessary for the correct comparison with the theory. The experimental results obtained on low heat conductive aerosols (or bodies) proved to be unsatisfactory either. One proposed an original method of thermophoresis measurement.