ISSN:
1435-1528
Keywords:
Second normal stress difference
;
concentrated suspensions
;
coneand-plate rheometer
;
steady shear
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Abstract In the present work the measurement and description of the second normal stress difference in pure viscoelastic fluids and in suspensions of these fluids is discussed. The various measurement methods implemented to date are described briefly. Following this, the cone-and-plate distance method, which was introduced by Jackson and Kaye, is discussed. The analysis method of this experimentally relative simply implemented technique is modified. This is done by assuming that the ratio ψ* of the second normal stress difference to the first is independent of shear rate. This permits the precalculation of the measured function with ψ* as a curve parameter. The best possible fit of the measurement leads to the determination of ψ*. This method is used to measure the normal stress ratio of pure polyisobutene and of a 34.5% suspension of the same fluid. The result for the pure fluid matches literature values; ψ* of the suspension was found to have negative sign, as for the pure fluid, but to be of much greater magnitude.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00366508
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