An Experimental and Theoretical Investigation of the Magnetization Properties and Basic Electromechanics of Ferrofluids,
Abstract
The purpose of this study is to investigate the basic magnetization processes and properties of ferrofluids and to apply these findings to the magnetic-field-coupled hydrodynamics (i.e. ferrohydrodynamics) of these colloidal liquids. This document reports progress over the last 12-month period. In basic ferrofluid properties studies, the authors have discovered a previously unreported agglomeration effect in commercially available 200 Gauss water-base ferrofluid. Upon the application of a uniform or non-uniform magnetic field, A.C. (60 Hz) or D.C., and any strength from 5 Oe to 230 Oe (limited by experimental apparatus), the formation of large agglomerates of up to 10 to the 9th power magnetite particles and with diameters from 10 to 20 micrometers has been observed. Agglomerate size increases with the magnetic field strength. The larger agglomeration effect in water-base ferrofluid can be explained theoretically as due to the larger diameter particles present in water-base fluid. Other theoretical results include (1) a calculation of the particle size dependence of the minimum magnetic field which is necessary for two particles to agglomerate, and (2) an estimate for the growth of sinking agglomerates due to scavenging.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1975
- Accession Number
- ADA016655
Entities
People
- D. A. Krueger
- T. B. Jones
Organizations
- Colorado State University