Planar light induced fluorescence quenching oxygen diffusivity measurement near the gas–liquid interface in aqueous glycerol and aqueous propylene glycol

Abstract

Experimental diffusivity data for gases in liquid mixtures are still scarce. To measure the diffusivity of dissolved oxygen in aqueous solutions of glycerol and propylene glycol, a planar light induced fluorescence (PLIF) method has been employed. The experimental method developed allows the measurement of the concentration field near the gas–liquid interface. The results show an increased oxygen diffusivity for the aqueous glycerol solution compared to the aqueous propylene glycol solution, corresponding to the lower viscosity of the solvent. Interestingly, during the first few seconds of oxygen absorption, a reduced early diffusivity is found for both experiments compared to later times. The results are compared with selected correlations and available experimental values. In general, the results are in good agreement with the literature data found and the discrepancy between early and later diffusivity is discussed.