Analytical Ultracentrifuge

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An analytical Ultracentrifuge is an instrument for highly precise characterization of disperse systems in a solvent, especially nanoparticles and macromolecules. The sample is separated by the centrifugal field and the distribution of different parameters of the sample is characterized. These are especially distributions of the sedimentation and diffusion coefficient, of the particle size and shape, the molar mass and density. For interacting systems, a characterization of the stoichiometry and equilibrium constants is possible. Since all particles/molecules are detected, the statistical significance of the measurements is very high. The resolution with respect to particle size is in the sub-nm regime. In addition, analytical ultracentrifugation is an absolute method meaning that no reference standards are needed. If a multiwavelength absorption detector is applied, different components in mixtures can be identified by their UV/Vis spectra. In addition, the dependence of the optical properties on the particle size can be directly determined, which is especially valuable for the analysis of metal and semiconductor nanoparticles with size dependent properties.The analytical ultracentrifuge shall be very broadly applied for the characterization of (bio)macromolecules and their interactions, of clusters, nanoparticles and their interactions, self-assembly and even complex fluids. Therefore, the instrument is important for the solution of a variety of scientific problems.