The principle of dynamic light scattering (DLS) is based on the Brownian molecular motion of smaller molecules or nanoparticles. If these are irradiated using a monochromatic and coherent laser beam at a known angle θ, the subsequent Rayleigh scattering of the individual scattering centers leads to smaller fluctuations in the scattering intensity which are recorded against time by the photon detector. The resulting speed of the nanoparticles within the dispersion medium enables the hydrodynamic radius of the individual particles to be calculated using the Stokes-Einstein equation. This measuring method provides information about the degree of agglomeration of the sample and conclusions about the stability of the dispersion. All measurements require a highly diluted dispersion of the specimen, which means that only quantities in the milligram range of the sample are required, which can also be completely recovered after the measurement has been completed.
Contact Person
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Prof. Dr. Sanjay Mathur 430 322b
- Phone
- +49 221 470-4107
- sanjay.mathuruni-koeln.de
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Dr. Thomas Fischer 421 322b
- Phone
- +49 221 470-3292
- t.fischeruni-koeln.de