Effect of a weak magnetic field on hematite sol in stationary and flowing systems

E. Tombácz, C. Ma, K. W. Busch, M. A. Busch

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

The effect of a weak magnetic field on the aggregation state and electrophoretic mobility of hematite sol was studied in flowing (dynamic) systems as a function of time and electrolyte concentration (0-60 mmol/dm3 KCl) and compared with the effect of the field in stationary (static) systems and flow in the absence of the field. During the entire treatment period, the pH remained almost constant (4.06-4.24). Conductance varied with KCl concentration, but except for minor fluctuations appeared to be unaffected by any form of treatment. While aggregation of hematite was observed during dynamic magnetic treatment (change in turbidity, scattered light intensity, and photon correlation spectroscopy), little effect on aggregation state was observed for the static systems or for the flowing systems in the absence of the field. Mobility also increased during the first 30 min of static and dynamic magnetic treatment. After longer treatment periods (90-120 min), the mobility decreased, but in almost all cases remained larger than in the case of untreated systems. Changes in both mobility and particle aggregation state also showed a significant dependence on electrolyte concentration. These effects are discussed in terms of a magnetohydrodynamic interaction between the magnetic field and the charged colloidal particles, which results only when the particles are made to pass rapidly through the field.

Original languageEnglish
Pages (from-to)278-289
Number of pages12
JournalColloid & Polymer Science
Volume269
Issue number3
DOIs
Publication statusPublished - Mar 1991

Fingerprint

Hematite
Polymethyl Methacrylate
hematite
Sols
Agglomeration
Magnetic fields
magnetic fields
Electrolytes
Photon correlation spectroscopy
Electrophoretic mobility
electrolytes
Turbidity
Magnetohydrodynamics
turbidity
Dynamical systems
magnetohydrodynamics
luminous intensity
ferric oxide
photons
spectroscopy

Keywords

  • aggregation
  • colloid stability
  • Hematite
  • magnetic field
  • magnetohydrodynamics

ASJC Scopus subject areas

  • Polymers and Plastics
  • Materials Chemistry
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

Cite this

Effect of a weak magnetic field on hematite sol in stationary and flowing systems. / Tombácz, E.; Ma, C.; Busch, K. W.; Busch, M. A.

In: Colloid & Polymer Science, Vol. 269, No. 3, 03.1991, p. 278-289.

Research output: Contribution to journalArticle

Tombácz, E. ; Ma, C. ; Busch, K. W. ; Busch, M. A. / Effect of a weak magnetic field on hematite sol in stationary and flowing systems. In: Colloid & Polymer Science. 1991 ; Vol. 269, No. 3. pp. 278-289.
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