Chemical reactivity of vinyltrimethoxysilane in aerosol particle formation with acrolein under two-photon excitation

2019/6/5

Under irradiation with N2 laser light, a gaseous mixture of Vinyltrimethoxysilane (VTMSi) and acrolein (AC) produced sedimentary aerosol particles with a mean diameter of 1.2?μm. From chemical analysis of the product by XPS and FT-IR spectroscopy, VTMSi was found to be incorporated into the sedimentary particles of polyacrolein as polysiloxane. Gas-phase chemical reaction between VTMSi and AC under irradiation with N2 laser light was investigated from the analysis of volatile products by GC/MS. Identification of cyclic polysiloxane in the gas phase strongly suggested that VTMSi molecules were cleaved at vinyl–Si bond and at O–CH3 bond by a two-photon process of N2 laser light, and produced dimethoxysilanone as an intermediate. The nucleation process of the aerosol particles was studied by measuring monitor (He–Ne laser) light intensity scattered by the aerosol particles as formed under irradiation with N2 laser light. With increasing partial pressure of VTMSi, the nucleation reaction of aerosol particles was accelerated due to the additional production of reactive species from VTMSi molecules.