Measurement of the Structural Unit in magnetic dispersions

摘要

Measurement of the Structural Unit (SU - containing both the solid phase and trapped-fluid within their associated structures) in magnetic dispersions has been carried out using Hindered Settling (HS) analysis that uses scanning column magnetometry and cone & plate rheology techniques. From this, an equivalent Stokes' particle diameter, d, of (5.2≤ d≤ 8.2) microns was determined that is approximately 22 times larger than the iron oxide particles of our formulation. A previous computer simulation based on HS theory produces complete concentration-height profiles of the sedimenting system over time that compare well when using a correspondingly large trapped-liquid fraction of around the 84% of the SU volume determined here, giving confidence in the result. As interest in iron oxide suspensions for potential biomedical and chemical decontamination/catalysis applications continues to grow an understanding of their structures is likely to become increasingly important.