Size distribution analysis of single and bi-component polymer and inorganic particle systems by comparison of two analysis methods in analytical ultracentrifuge

Sedimentation velocity runs were performed on organic and inorganic particles with analytical ultracentrifugation and the diameter and diameter distribution analysis was carried out with Sedfit and VelXLAI data analysis programs. The particles were measured either as pure components or as mixtures of different organic or inorganic particles using different weight ratios of these components. Polymer particles with peak diameters of ≈15 and 32–35 nm and inorganic particles with peak diameters of ≈5 and ≈32 nm were used and the particles also differed in the extent of polydispersity. The mixtures of particles in the weight ratios of 50:50, 90:10 and 95:5 of smaller to larger particles or vice versa were studied. The aim was to compare the performance of the analysis programs to characterize the various polymer and inorganic particle samples of varying complexity. The analysis programs were compared with each other not only for peak particle diameters and their size distributions, but also for the cumulative fractions of components of the particle mixtures.

Differential particle size distributions of the mixture of smaller and larger inorganic particles in the weight ratio of 5:95. The particles were analyzed separately at 10,000 and 30,000 rpm (solid line: VelXLAI, dotted line: Sedfit). Both the fractions were also analyzed at 10,000 rpm alone using VelXLAI program (-□-).Figure optionsDownload high-quality image (84 K)Download as PowerPoint slideResearch highlights
► Comparison of two common data analysis programs in analytical ultracentrifugation.
► Both polymer and inorganic suspensions as well as mixtures evaluated.
► Advantages and limitations of programs for data analysis on complex mixtures established.