Analytical ultracentrifugation of model nanoparticles: comparison of different analysis methods.

Sedimentation analysis of nanoparticle (ZrO(2) and SiO(2)) suspensions of different particle sizes in various solvents as nanoparticle model systems was carried out using interference optics in the analytical ultracentrifuge. The particles differed in their morphology: SiO(2) particles were spherical, whereas ZrO(2) particles were in one case spherical and in the second case non-spherical and spherical. Different analysis programs, based on different principles of data analysis, were used for the evaluation of the size distributions of these particles, viz. SEDFIT [ls-g*(s), c(s)], UltraScan (vHW, 2DSA-MC), SedAnal (dcdt) and VelXLAI (GFL) method and SedAnal, in order to ascertain the benefits and limitations of these analysis methods in characterising the examined nanoparticles.