Benzil fluorescence and phosphorescence emissions: a pertinent probe for the kinematic behaviour and microheterogeneity of supercritical CO2

The relative intensity (RI) of the phosphorescence and fluorescence from the relaxed trans-planar geometry of benzil has been studied as a function of pressure and temperature in supercritical carbon dioxide (SC-CO2). The nature of the variation of RI with pressure and temperature is similar to that of the kinematic viscosity (KV) with the two said parameters. The experimental results have been interpreted in terms of microheterogeneity of the supercritical fluid (SCF).