Interfacial Shear Rheometer
From KSV NIMA
The Interfacial Shear Rheometer (ISR) provides an accurate and quantitative method to measure the shear properties of fluid interfaces (gas/liquid or liquid/liquid). The ISR can be combined with a KSV NIMA Langmuir trough, allowing measurements on both soluble and insoluble films.
|Dynamic and static measurements|
|Measurement of viscoelasticity of interface layers|
|Optional: Low volume measurement cell requiring as little as a 4.7 ml of subphase|
In the ISR a magnetized probe, positioned at the air-liquid or liquid-liquid interface, is moved using a magnetic field. The movement of the probe is recorded with a digital camera from above. By measuring any changes in movement of the probe the surface modulus can be calculated and divided into the elastic and viscous properties of the film.
Combining the KSV NIMA ISR with a Langmuir trough or liquid-liquid trough enables the compression of both soluble and insoluble films to be controlled during the measurements. As with any KSV NIMA Langmuir trough, measurements of isotherms, isobars and interfacial dilatational rheology are possible.
When working with valuable compounds and subphases, the KSV NIMA ISR can be used with the low volume measurement cell which requires as little as a 4.7 ml of subphase. It is ideal for studying material adsorption and reaction at interfaces.
- Dynamic moduli resolution (mN/m): 0.001
- Frequency range (rad/s, Hz): 0.01-10, 0.0016-1.6
- Strain range: 3x10-4 to 1
- ISR with Langmuir Trough (L × W × H, cm): 90.8 × 37.0 × 70.0
- ISR with Low Volume Cell (L × W × H, cm): 19.0 x 37.0 x 70.0
The relationship between stresses and deformation defines the rheological properties of a film. Most systems encountered in industry and in biology are viscoelastic films where these relationships are nonlinear and intermediate between purely viscous and purely elastic responses. The rheological properties are extremely important for defining product stability in different industries such as food, petrochemical, cosmetics, and pharmaceuticals.
Prediction of emulsion, froth and foam stability
Viscoelasticity of an interface can predict the stability of a complex fluid. Micelle/droplet fusion and fission are largely dependent on the interface viscoelasticity.
Film structure in monolayers
Determination of thin film structure
The presence of networking, hydrogen bonding and other interactions can be detected from the viscoelastic behavior of films.