Small angle x-ray scattering study of flame soot nanoparticle aggregation and restructuring

Results of an in situ small angle x-ray scattering (SAXS) study of soot particles are presented. Scattering data are analyzed using two Fourier transform inversion methods to determine particle volume distributions and by means of the unified function, which allows different structural levels in the scattering objects to be distinguished. We are able to observe the contemporary existence of smaller subprimary particles and larger aggregated particles that usually are classified as primary particles and constitute the building bricks of large fractal-like aggregates with external dimension of above 100 nm. Comparison is made with our previous SAXS and near edge x-ray absorption fine structure spectroscopy results and with those obtained using laser light scattering and particle sampling-electron microscopic methods.