Investigation of molecular interactions and local fields in liquids and gases by optical Kerr effect method

Authors:

• Zdzisław Błaszczak

Abstract

The optical Kerr effect (OKE) yields useful information concerning molecular interactions and local fields in a medium. However, the interpretation of results obtained in dense media is often problematic, especially in the attempt to determine the contributions of different types of molecular interactions to the optically induced birefringence. The enhanced sensitivity of our experimental device now permits OKE measurements in gases and vapours. The device was tested on liquid and gaseous carbon dioxide. Laser-induced OKE was measured and compared in liquid and gas carbon dioxide. The contribution to OKE from a single carbon dioxide molecule in gas and vapour phase is 7.6 and about 3 times greater than the contribution of the same molecule in liquid phase. This experimental result shows that the effective molecular anisotropy of the carbon dioxide molecule in the liquid phase is markedly lower than its value in the gas phase.