Effect of Optical Density on n-Butyraldehyde Photooxidation

Abstract

To discuss the influence of optical density on a light-induced chain reaction with biradical termination, photooxidation experiments were carried out on the initial reaction rates with different reactant concentrations of n-butylaldehyde.
Efficiency of active radical utilization obtained in the optically dense concentration contrasts with the value derived by the constant diffusion coefficient in constant mixing. The increase of reactant concentration produce a steeper profile of light intensity, and almost all of incident light is absorbed in the boundary layer of the vicinity of the incident wall. Then, the results are fairly well explained by the decrease of overall diffusion coefficient in the high optical density, considering of molecular diffusion in the boundary layer.