Chocolate at sliding Interfaces

Picture 1

Molten chocolate is an example of a complex fluid showing non-Newtonian (i.e. drag increases non-linearly with shear rate) rheological properties. In addition to a conventional rheological characterization, friction measurements with molten chocolate as a boundary lubricant sensitively provide additional information about the interfacial properties. In collaboration with a chocolate manufacturer, we are currently investigating the possible use of this sensitivity for the characterization of molten chocolate samples. A comparison of tribological properties with conventional data from rheology and sensory panels revealed interesting correlations.

Picture 2

In this context, we are also studying the tribological properties of other complex fluids and model suspensions. The temporal evolution of the friction force, F(t), is found to be strongly dependent on the choice of the substrate materials. Comparative pin-on-disk studies revealed that asymmetric tribo-pairs (two different substrate materials) are not interchange-invariant and can indeed be used to gain valuable additional insight. A system A/B may thus exhibit considerably different tribological behavior than the analogue B/A system

Picture 3

Contact:

• Seunghwan Lee