Photochemical sensitization and magnetic field effect on aerosol particle formation from a gaseous mixture of glyoxal and acrolein

Under light irradiation at 435.8 nm with a medium pressure mercury lamp, pure acrolein (AC) vapour does not produce any deposits, but a gaseous mixture of glyoxal (GLY) and AC produced sedimentary aerosol particles. The nucleation process of the aerosol particles was investigated by measuring He-Ne laser light intensity scattered by the aerosol particles as formed under light irradiation at 435.8 nm. From the dependence of the scattered light intensity on the partial pressure of GLY, it was found that electronically excited GLY in the nπ? state initiated chemical reactions with AC leading to nucleation of the aerosol particles. Magnetic field effects on the nucleation process were measured for a gaseous mixture of GLY and AC. With the application of a magnetic field of 5.3 kG, the nucleation reaction was accelerated, and the convection of the gaseous mixture was changed due to greater heat release during nucleation reaction between GLY and AC. The magnetic field effect on the gaseous mixture is discussed based on the photochemical behaviour of GLY.