Oxidation of polystyrene aerosols by VUV-photolysis and/or ozone.
Aerosols of submicron polystyrene particles were oxidized by either vacuum-ultraviolet (VUV) irradiation in the presence of molecular oxygen (O(2)) and/or by ozone (O(3)). Different degrees of oxidation and oxidative degradation were reached by VUV-photolysis depending on radiant energy, O(2) and H(2)O concentrations in the bulk gas mixture as well as on particle diameter. The same functionalization was obtained by exposing the aerosol to O(3), however, oxidation, in particular oxidative degradation, was less efficient. The evolution of hydroxyl and carbonyl functions introduced was quantified by ATR-FTIR spectroscopy of filtered particles, and oxidative degradation of the polymer particles was confirmed by determining size and number of aerosol particles before and after oxidation. Efficiency analyses are based on the results of an O(3) actinometry and on an evaluation of the rate of absorbed photons by the aerosol particles in function of their size.
Vicente
José Salas
JS
Lehrstuhl für Umweltmesstechnik, Engler-Bunte-Institut, Universität Karlsruhe, Germany.
Gejo
Juan López
JL
Rothenbacher
Sonja
S
Sarojiniamma
Sumalekshmy
S
Gogritchiani
Eliso
E
Wörner
Michael
M
Kasper
Gerhard
G
Braun
André M
AM
D000336:Aerosols / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014466:Ultraviolet Rays; D014618:Vacuum
D000336:Aerosols; D011137:Polystyrenes; D010126:Ozone; D010100:Oxygen