Effect of hydrodynamic size on colloidal stability and lifetime of Mn-Zn magnetic fluids
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For transformer cooling applications, magnetic particles need to be dispersed in carrier fluids with high colloidal stability for a long period without significant degradation. However, stability of the suspension, especially the long term colloidal stability is a crucial factor for the applications in power transformers because aggregation of particles could cause clogging of micro-channels in transformers. In this article, we have reported effect of hydrodynamic size on the colloidal stability of Mn1-xZnxFe2O4 (MZ) nanoparticles (NPs)–based magnetic fluids. Lifetime of fluids has been determined from the increase in hydrodynamic size of magnetic NPs due to aggregation. Colloidal stability of fluids decreases with increase in the polydispersity of fluids caused by the enhanced dipole interactions between NPs resulting in the aggregation of NPs in chain-like structures.
KeywordsMagnetic fluids Aging Colloidal stability Hydrodynamic particle size
- Vibrating sample magnetometer
- Mn1-xZnxFe2O4 (x = 0−1) fluid
- Mn1-xZnxFe2O4 (x = 0−1) nanoparticles
N. Kaur is thankful to MANF (UGC-New Delhi) (F1-17.1/2015-16/MANF-2015-17-PUN-53556). The financial support from DST New Delhi (DST FIST scheme no. SR/FST/PSI-176/2012) and Council of Scientific and Industrial Research, New Delhi (scheme No. 03(1226)/12/ERM-II) is gratefully acknowledged.
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Conflict of interest
The authors declare that they have no conflict of interest.
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