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Shear Indxuced order of Cncenirated Dispersions

Published online by Cambridge University Press:  28 February 2011

Eruce J. Ackerson
Affiliation:
Department Of Physics, Oklahoma State University, Stillwater, Ok 74078
T .A. Morris
Affiliation:
Department Of Physics, Oklahoma State University, Stillwater, Ok 74078
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Abstract

The microstructure or interparticle ordering in concentrated dispersions of colloidal pmma (polymethylnethacrylate) particles in a mixture of tetralin and decalin have been monitored using light scattering techniques. These sterically stabilized, uniformly sized, nearly hard, colloidal spheres are observed to exhibit an equilibrium phase transition from a liquid-like ordering to a crystal-like ordering of suspended particles as the volume fraction of solids increases. The crystals have a close packed - random stacked structure. At the largest volume fractions a nonequilibrium glassy phase results.

Samples at different volume fractions are subjected to steady and oscillatory shear flow. Four basic structures are observed to exist: liquid or distorted liquid-like, string-like, sliding or randomly stacked layers, and face centered cubic (FCC) structures. Oscillatory shear studies will be reported here and are made as a function of strain amplitude and shear history, in addition to volume fraction. Generally, oscillatory shear is effective in ordering samples. For example, an unstable FCC ordering can be induced in an equilibrium liquid-like sample.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1. Scott, G.D., Nature 188, 908 (1960).Google Scholar
2. Kittel, C., Introduction to Solid State Physics, 5th ed. (Wiley, New York, 1976), chapter 1.Google Scholar
3. Bernal, J.D., Nature 183, 141 (1959).Google Scholar
4. Scott, G.D., Charlesworth, A.M., and Mak, M.K., J. Chem. Phys. 40, 611 (1964).Google Scholar
5. Bernal, J.D., Proc. Roy. Soc. 280, 299 (1962).Google Scholar
6. Ackerson, B.J., J. Rheol. (to be published).Google Scholar
7. Hoover, W.G. and Ree, F.H., J. Chem. Phys. 49, 3609 (1968).Google Scholar
8. Pusey, P.N., J. Phys. (Paris) 48, 709 (1987).Google Scholar
9. Paulin, S.E. and Ackerson, B.J., (submitted to the Physical Review Letters).Google Scholar
10. Pusey, P.N., van Megen, W., Nature 320, 340 (1986).Google Scholar
11. Kittel, C., Introduction to Solid State Physics, 5th ed. (Wiley, New York, 1976), chap. 2.Google Scholar
12. Pusey, P.N., van Megen, W., Bartlett, P., Ackerson, B.J., Rarity, J.G., and Underwood, S.M., Phy. Rev. Lett. 63, 2753 (1989).Google Scholar
13. Ackerson, B.J., Hayter, J.B., Clark, N.A., and Cotter, L., J. Chem. Phys. 84, 2344 (1986);Google Scholar
13a Pieranski, P., Contemp. Phys. 24, 25 (1983).Google Scholar
14. Krieger, I.M., Adv. Coll. Interface Sci. 3, 111 (1972).Google Scholar
15. Woodcock, L.V., Phys. Rev. Lett. 54, 1513 (1985).Google Scholar
16. Aastuen, D.J.W., Clark, N.A., Cotter, L.K., and Ackerson, B.J., Phys. Rev. Lett. 57, 1733 (1986).Google Scholar
17. Russel, W.B., Phase Transitions, (to be published).Google Scholar
18. Patzold, R., Rheol. Acta. 19, 322 (1980).Google Scholar
19. Hoffman, R.L., Trans. Soc. Rheol. 16, 155 (1972).Google Scholar
20. Hoffman, R.L., J. Coll. Interface Sci. 46, 491 (1974).Google Scholar
21. Nelson, D.R. and Halpern, B.I., Phys. Rev. B19, 2457 (1979);Google Scholar
21a Young, A.P., Phys. Rev. B19, 1855 (1979);Google Scholar
21b Shi, L.T. and Krakow, W., Phys. Rev. B34, 7407 (1986).Google Scholar