TABLE OF CONTENTS AUC is one of the most universally applicable and variable physicochemical techniques for the characterization of colloidal or polymeric systems in solution, dispersion, or emulsion. The power of AUC lies in the fractionation of the sample due to either the molar mass/size (sedimentation velocity/sedimentation equilibrium) or due to the chemical structure (density gradient) in the solvent and, therefore, its capacity to measure distributions without any interaction with stationary phase or solvent flows, as occurs in the applied chromatographic techniques commonly nowadays. Wherever information is sought for the individual components in a mixture, AUC is among the first techniques of choice. On the other hand, sedimentation equilibrium is an equilibrium well described by thermodynamics. Thus, it is possible to derive information even on complicated or interacting systems on an absolute basis without disturbing this equilibrium. Many different physicochemical quantities can be determined. Very often, even simple investigations such as those of sample homogeneity can provide much information on a system. But a complete physicochemical characterization is also possible, often with information that cannot be obtained by means of other techniques. As for other analytical techniques, the rapid computer and electronics development of the past years was of benefit for AUC. This development provides many new applications, improved sensitivity of the experiments and even the realization of evaluation approaches not possible so far. Not only has the amount of experimental data that can be obtained from an ultracentrifuge experiment increased, the amount of information it yields has also increased. This...
