ARES – Advanced Rheometric Expansion System
Manufacturer: Rheometric
Scientific, USA.
Model: ARES - Advanced Rheometric
Expansion System
ARES stands for Advanced Rheometric
Expansion System and is the first truly modular
rheometer designed for the changing needs of Materials Research and Process
Development laboratories. It is
developed by the world leader in Rheological and Thermal Analysis Instrumentation.
Applicable for testing almost any material-thermoplastics, thermosets, elastomers, or fluids-ARES provides a practical, versatile, and accurate rheometer that adapts to changing applications needs and continues the long tradition of Rheometric Scientific product quality.
Technology:
1) Transducer
The equipment is loaded with a 2000 gram Force rebalance transducer, which provides high frequency response with the ruggedness demanded by QC labs. FRT transducers are air-lubricated and essentially non-compliant, with high sensitivity. These transducers show extremely small temperature drift and provide excellent dynamic response over the whole frequency range, and provide the highest quality Normal force measurements available.
2) 7-decade dynamic frequency range
ARES has a frequency range of 1e-5 to 500 radians/second with a resolution of 0.098% of commanded frequency, the widest frequency range of any controlled strain rheometer. This wide range is important for complete material characterization and direct measurement of material properties
3) Temperature accuracy
PRT temperature sensing for increased accuracy. Thermocouples have an accuracy of ± 1.1°C (some are as low as ±2.2°C), PRT accuracy is ± 0.35°C, three times as accurate as a thermocouple.
4) Surface of contact & sample size
The surface of contact can be
varied using different sizes of plates or cones. Disposable plates can be attached to curing products such as not
to damage the tool fixture. The
size of the plates also plays an important role in the experiment and
the calculation of the modulus.
Applications:
With the increasing interest in Life Sciences,
Physical properties are also important. Gels are highly rated as a good material for biomedical applications.
Gels can either be hydrogel (water based) or organogel (oil based).
Due to its biological compatibility, organogels
are used in “Transdermal Drug Delivery”. Other uses for cosmetics are being studied. The microstructure of the gel is correlated
to its physical properties. Gels
are visco-elastic materials, and properties like viscosity and elasticity
are investigated at different temperature and frequency.
Examples of Applications:
1) Time/Temp Sweep
This experiment is used to find the “Time
of gelation”, which is in lay-man’s term, the time at which the gel
will change from a liquid state to a solid state (solidify) under specific
environmental conditions. This
is achieved by finding the values of Viscous and Elastic Modulus (G’ and
G’’).
G’ and G’’ decreases
as the gel becomes a liquid and when the temperature ramps down, the values
of G’ and G’’ starts to increase.
2) Dynamic Strain Analysis
The microstructure of gels shows that
there is a network, which holds the gel together. This has a certain critical strain whereby; a value above this would
destroy the network.
The gel is put
under a dynamic condition with an oscillating motion. Above the critical strain, the gel will behave
differently on the microscopic level, which may not be useful in out applications
such as transfer of drugs, or wound healing.
3) Dynamic Temperature
Ramp
This test is used to
investigate the relationship of the modulus with temperature. For curing samples, this test shows at what
specific temperature, curing will takes place, and also how the sample
behaves after being heated.
Apart from those mentioned above,
ARES can also be applied to carry out the following tests:
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