Within the scope of the Master’s thesis, the suitability of a variety of laboratory devices was tested on their capability to characterize flocculation in a model suspension. The objective was to link the change in rheology with the change in fluid structure. The change in rheology was measured by a standard laboratory rheometer. Additional information was gained by the testing of the magnetic resonance imaging coupled with a rheometer. As a model suspension, calcium carbonat Durcal 5 mixed in different ratios with a mixture of 70 % glucose and 30 % water, was used. By the application of calcium carbonat, the impact of change in rheology by cement hydration could be eliminated. Glucose helped to avoid sedimentation in the suspension. Flocculation was tested with the help of the following laboratory devices: Transmitted light microscopy, Confocal microscopy, Laser particle sizer, Focused beam reflectance measurement (FBRM®), Particle vision microscopy (PVM®), X-ray microtomography and Static multiple light scattering (Turbiscan), to evaluate their suitability to follow an evolution process of flocculation in a dense opaque suspension. Applying different devices on the model suspension enabled to gain useful information to study flocculation in a dense opaque suspension. By the help of the transmitted light microscope, floc size and floc shape could be measured. With the Laser particle sizer it was possible to study the evolution of floc size with time. At the Bruker Minispec, a flocculation process was observed with the measurement of local change in particle concentration with time. Based on the rheology measurements at a rheometer, the flocculation process could be coupled with the change of rheology properties of the suspension. Additional results were obtained by concentration and velocity profile measurements at the magnetic resonance imaging coupled with a rheometer. The measurement at the Focused beam reflectance measurement (FBRM®), Particle vision microscopy (PVM®) and X-ray microtomography has to be further improved. Turbiscan turned out to be not capable to measure an floccs evolution process.
|Translated title of the contribution
|Messverfahren in geflockten Systemen
|28 Jun 2013
|Published - 2013
Bibliographical noteembargoed until null
- flocculated systems
- calcium carbonat