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Phase Diagrams of Electric-Fduced Aggregation in Conducting ColloidsUnder the application of a sufficiently strong electric field, a suspension may undergo reversible phase transitions from a homogeneous random arrangement of particles into a variety of ordered aggregation patterns. The surprising fact about electric-field driven phase transitions is that the aggregation patterns, that are observed in very diverse systems of colloids, display a number of common structural features and modes of evolution thereby implying that a universal mechanism may exist to account for these phenomena. It is now generally believed that this mechanism emanates from the presence of the long-range anisotropic interactions between colloidal particles due to their polarization in an applied field. But, in spite of numerous applications of the electric-field-driven phenomena in biotechnology, separation, materials engineering, chemical analysis, etc. our understanding of these phenomena is far from complete. Thus, it is the purpose of the proposed research to develop a theory and then test experimentally, under normal- and low-gravity conditions, the accuracy of the theoretical predictions regarding the effect of the synergism of the interparticle electric and hydrodynamic interactions on the phase diagram of a suspension. The main results from our theoretical studies performed to-date enable one to trace how the variations of the electrical properties of the constituent materials influence the topology of the suspension phase diagram and then, by using an appropriate phase diagram, to evaluate how the electric-field-induced transformations will depend on the frequency and the strength of the applied field.
Document ID
20010004322
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Khusid, B.
(City Univ. of New York NY United States)
Acrivos, A.
(City Univ. of New York NY United States)
Date Acquired
August 20, 2013
Publication Date
March 1, 1999
Publication Information
Publication: Proceedings of the Fourth Microgravity Fluid Physics and Transport Phenomena Conference
Subject Category
Fluid Mechanics And Thermodynamics
Funding Number(s)
CONTRACT_GRANT: NSF CTS-93-18820
CONTRACT_GRANT: NCC3-607
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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