Oscillatory test: Frequency sweep

During the frequency sweep the frequency is varied while the amplitude of the deformation - or alternatively the amplitude of the shear stress - is kept constant. For the analysis the storage and loss modulus are plotted against the frequency. The data at low frequencies describe the behaviour of the samples at slow changes of stress. Oppositional the behaviour at fast load is expressed at high frequencies.
The frequency sweep is very important for polymer melts. For dispersions (e.g. paints, cosmetics, comestible) this method can provide some information about the sedimentation stability.

 

Frequency sweep:The graph shows a behaviour of G' and G'' that is typical for a polymer melt or polymer solution.