When a small amount of a second immiscible liquid is added to the continuous phase of a suspension, the rheological properties of the mixture are dramatically altered from a fluid-like to a gel-like state or weakly elastic to strongly elastic state, increasing the yield stress and viscosity by several orders of magnitude. This transition is attributed to the capillary forces of the two fluids on the solid particles.
The CapS research group studies the material properties of these as well as applications where this capillary suspension concept can be utilized. We investigate the properties of the induced particle network using microscopy techniques, where the network can be imaged in 3D and directly manipulated. Changes to the network are then connected to changes in the macroscopic material properties as measured using rheological techniques. This adjustable material response can then be used for the intelligent design of crack-free films as well as highly porous materials for filters and catalysts.
Funding has been provided by:
- European Research Council under the European Union's Seventh Framework Program (FP/2007-2013)/ERC Grant Agreement no. 335380
- German Research Foundation (Deutsche Forschungsgemeinschaft grant no. KO4805/2-1)
- Helmholtz Association (Helmholtz Gemeinschaft Sonderprämie)