Rheological technique

R. W. Whodow, Rheological Techniques, Halsted Press, a division of John Wiley Sons, Inc., New York, 1980. 

Whorlow RW (1980) Rheological Techniques. EUis Norwood, Chichester... 

Hvidt, S Jorgensen, EB Brown, W Schillen, K, Micellization and Gelation of Aqueous Solutions of a Triblock Copolymer Studied by Rheological Techniques and Scanning Calorimetry, Journal of Physical Chemistry 98, 12320, 1994. 

For the continuous mode, we utilized a dynamic rheological technique, Fourier transform mechanical spectroscopy (FTMS) (77,75), which provided a powerful method for monitoring, simultaneously, the evolving dynamic moduli at several frequencies during the course of photo-cross-linking. In this technique, an oscillatory strain, y, was applied to the sample, such that... 

Figure 8. The extent of reaction as a function of UV exposure time, collected from real-time FTIR, along with the elastic modulus (GO as a function of UV exposure time, measured by the in situ rheological technique, shows that an appreciable elastic modulus appears only after high extents of reactions are reached.

In this section we deal with perhaps the most conceptually difficult of all the responses observed in linear viscoelastic materials. This is the response of a material to an oscillating stress or strain. This is an area that illustrates why rheological techniques can be considered as mechanical spectroscopy. When a sample is constrained in, say, a cone and plate assembly, an oscillating strain at a given frequency can be applied to the sample. After an initial start-up period, a stress develops in direct response to the applied strain due to transient sample and instrumental responses. If the strain has an oscillating value with time the stress must also be oscillating with time. We can represent these two wave-forms as in Figure 4.6. 

Much less is known about the settling of particles in fluids exhibiting a yield stress. Barnes (39) suggests that this is partly due to the fact that considerable confusion exists in the literature as to whether or not the fluids used in the experiments do have a true yield stress 39. Irrespective of this uncertainty, which usually arises from the inappropriateness of the rheological techniques used for their characterisation, many industrially important materials, notably particulate suspensions, have rheological properties closely approximating to viscoelastic behaviour. 

J.W. Goodwin and W.B. Russel Rheology and Rheological Techniques. Curr. Opin. Colloidal Interface Sci. 2, 409 and references therein (1997). 

It was of interest to compare the results obtained with the FRAP technique with those obtained with classical surface rheological techniques. Our detailed knowledge of properties of solutions of /3-lg containing Tween 20 made this an ideal system on which to compare the methods. Firstly, surface shear viscosity measurements were performed on the Tween 20//3-lg system [47] using a Couette-type torsion-wire surface rheometer as described previously [3,48]. All the experiments were carried out at a macroscopic n-tetradecane-water interface at a fixed protein concentration of O.Olmg/ml. In the absence of Tween 20, the surface shear... 

Viscosity. This parameter can be monitored by standard rheological techniques. The rheological properties of emulsions, reviewed by Sherman (1983), can be complex, and depend on the identity of surfactants and oils used, ratio of disperse and continuous phase, particle size, and other factors. Flocculation will generally increase viscosity thus, monitoring viscosity on storage will be important for assessing shelf-life. 

Whorlow, R.W. Rheological Techniques, Ellis Horwood Chichester, England, 1980. 

Whorlow RW. Rheological Techniques. Chichester, UK Ellis Harwood 1980. 

Application of Rheological Techniques to Milk Fat and Milk Fat-Based Dairy Products... 

The Pitch-Mesophase-Coke Transformation As Studied by Thermal Analytical and Rheological Techniques... 

Whorlow R, "Rheological Techniques", Ellis Horwood, Chichester, 2nd Ed, 1992. 

This paper describes the general methodology and some results of the study of thermoset systems by rheological techniques, chiefly in steady rotation. Analysis of the experimental cure curve is described in detail, and the use of chemorheologioal data to correlate and predict product performance as well as provide guidance for formulation, is discussed. 

Mitchell, J. R. 1984. Rheological techniques, in Food Analysis Principles and Techniques, eds. 

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