| Abstract: | The dependence of the integral intensity of the absorption bands due to the stretching vibrations of the NH groups of phthalimide and diphenylamine vapor on helium and nitrogen concentration has been used to study thermal diffusion in binary vapor-gas mixtures. A decrease or increase in absorption is observed, depending on the magnitude of the temperature gradient in the phthalimide-nitrogen mixture; this is related to a change in the sign of thermal diffusion. In the absence of a temperature gradient, added gases have no influence on the vibrational absorption bands of polyatomic molecules. |
