I have not found any literature referring to the role of electrostatic forces in water or oil based ferrofluids coated with ionic surfactants. Do they play any role in applications of ferrofluids? What can be the possible magnitude of these forces to completely neglect them?
I typed "ferrofluid emulsion + "electrostatic repulsion"" into Google Scholar and found a significant number of relevant papers. Including those that I expected from the Bordeaux group on using ferrofluid droplets to measure inter-droplet repulsion.
Thank you Alan, I was looking in thermal and fluid domain literature and couldn't found any mention of electrostatic forces. I certainly have keywords to look at right place now.
In coating of oliec acid it should be known whether you are creating chemisorb or physically adsorb on the surface of the particle. If it is chemically adsorb, then electrostatic repulsion does not come into a picture, rather it is a stearic repulsion and dipolar interaction plays an important role. As both the forces affects the thermal properties of the magnetic nanofluid. You can refer our paper on "maneuvering of thermal conductivity..." and other papers on ultrasonic studies available from research gate.
The role of these surfactants, which are coated on the surface of magnetic nanoparticles is stabilization. They increase long-term stability of ferrofluids.
However, if you want to tune interfacial tension of the ferrofluids then you need to add other types of surfactants, eg. Span 80 for oils or tween 20 for water - based ferrofluids.
Dear Dr. Jaykumar, thank you for your informative comment. I was looking for something similar.
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