Accessory for MCR:
Interfacial Rheology System

Analyze emulsion and foam stability on your MCR rheometer

An MCR rheometer combined with an Interfacial Rheology System enables the measurement of the flow and viscoelastic properties directly in the interface of interfacial layers. These properties directly correlate with the rheology of emulsions and foam stability. Integrated Peltier elements allow you to set the sample temperature in the range from 5 °C to 70 °C. Measurements can be performed in rotational and oscillatory mode for extended analysis, e.g. flow curves and creep tests at an interfacial layer or oscillatory tests during the film formation process.

Even for measuring weak interfacial structures and over the full viscosity range

The bi-cone measuring system (68 mm, 2 x 5°) or the double wall ring (DWR)^* with very sharp edges is placed in the layer interface and measures absorbed or spread films, e.g. films produced by proteins or surfactants. Even the weakest interfacial structures can be measured with the low-torque capabilities and the TruStrain™ feature. 

The bi-cone, double wall ring^* and Du Noüy Ring guarantee the measurement of a unique range of interfacial viscosities and shear moduli. The normal force sensor in the air bearing of the MCR rheometer allows automated positioning of the measuring geometry.

The full range of analysis possibilities in shear rheology

RheoCompass, the proven rheometer software, is able to compensate the influence of the bulk and upper phase of the flow field in the Bi-cone system directly after the measurement. The analysis takes into account the complex coupling of the interface with the liquid sub-phase and reveals absolute interfacial shear rheology properties. All measured and calculated interfacial data is recorded and displayed. Moreover, predefined interfacial rheology workbooks are available for fast and convenient operation.

Choose the ideal interfacial rheology setup according to your specific needs

The IRS is also available as a “small sample volume” version, reducing the needed sample volume to 40 mL, which is especially important for materials that are only available in a limited amount. Furthermore, the system can be connected to a flow-through option, which makes it possible to change the composition of the interfacial system directly within the measuring device and even during the rheological test. This enables the direct and real-time analysis of effects caused by e.g. changes in pH value, salt concentration, or the introduction of new surface active ingredients. It is also possible to investigate interfacial transport processes and their connection to rheological properties. Even a Langmuir trough can be integrated in order to create interfacial layers with controlled packing density.

Deeply explore the rheology of emulsions, suspensions, and foams

Interfacial rheology plays an important role in many products and processes. Whenever there is a two-dimensional liquid/liquid or gas/liquid interface, the distinct rheological properties should be investigated since they determine the behavior and stability of e.g. suspensions, emulsions, and foams. Typical examples are surfactants and surface active polymers which are used for stabilizing emulsions and foams in the food and cosmetic industries in order to improve shelf life.

Other examples for such materials include:

• Food products, e.g. coffee crema
• Consumer products, e.g. detergents
• Pharmaceuticals and cosmetics, e.g. encapsulation, drug release, soap
• Oil industries, e.g. water-oil systems  
• Life science and medicine, e.g. eye drops, body liquids