Analytical ultracentrifugation (AUC) is a powerful method for the characterization of polymers, biopolymers, polyelectrolytes, nanoparticles, dispersions, and other colloidal systems. The method is able to determine the molar mass, the particle size, the particle density and interaction parameters like virial coefficients and association constants. Because AUC is also a fractionation method, the determination of the molar mass distribution, the particle size distribution, and the particle density distribution is possible. A special technique, the density gradient method, allows...