Abstract
IN view of a recent statement1 “that solutions of macromolecular substances may show an anomalous fall in the coefficient of viscosity at high rates of shear”, it is emphasized once again2 that, at sufficiently high rates of shear, any liquid consisting of elongated molecules must be expected to exhibit a decrease of the coefficient of viscosity with increasing rate of shear. This means that there is only a quantitative, but no qualitative, difference between the dependence of viscosity on rate of shear of so-called Newtonian liquids and that of solutions of macro-molecular substances. Grunberg and Nissan3 estimated that at a rate of shear of about 106 sec.−1 pentane might begin to show an appreciable reduction of viscosity, and Bondi4 predicted that temporary reductions of viscosity would become apparent for shearing stresses of more than 105 dynes/cm.2 for straight hydrocarbon chains with molecular weights of 500 and more. In addition to our own previous results on castor oil and straight mineral oils5, experimental evidence is now presented to prove that a chemically defined liquid, such as tetradecane, suffers an appreciable fall of its coefficient of viscosity over a range of rates of shear extending to about 350,000 sec.−1.
Similar content being viewed by others
Article PDF
References
Ward, A. F. H., Neale, S. M., and Bilton, N. F., Nature, 166, 905 (1950).
Schnurmann, R., and Morris, W. J., “Principles of Rheological Measurement”, 208 (London, 1946).
Grunberg, L., and Nissan, A. H., Nature, 156, 241 (1945).
Bondi, A., J. App. Phys., 16, 539 (1945).
Schnurmann, R., Proc. Int. Rheol. Congr. Holland, 1948, Pt. 2, 142.
Morris, W. J., and Schnurmann, R., Rev. Sci. Instr., 17, 17 (1946).
Schiller, L., and Kirsten, H., Phys. Z., 22, 523 (1921).
Morris, W. J., “Jet Viscometers for High Rates of Shear”, M.Sc. Thesis (Manchester, 1948).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
MORRIS, W., SCHNURMANN, R. Temporary Reduction of Viscosity of Liquids at High Rates of Shear. Nature 167, 317 (1951). https://doi.org/10.1038/167317a0
Issue Date:
DOI: https://doi.org/10.1038/167317a0
This article is cited by
-
Evaluation of high shear viscosity data from jet and concentric cylinder viscometers
Rheologica Acta (1962)
-
Viskosität und Konstitution
Kolloid-Zeitschrift (1952)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.