It appears that getting oil and water (or fuel and water) to mix is as simple as degassing the water.
https://www.newscientist.com/article...mix-after-all/
Quote:
If you first remove any gas that is dissolved in the water, it will mix spontaneously and even stay that way indefinitely, according to chemist Ric Pashley of the Australian National University in Canberra.
Once the emulsion has formed, hydroxyl groups from the water adsorb onto the surface of the oil droplets, making them similarly charged and thus preventing them from coming close together.
To test his hunch, Pashley removed almost all the gas from a water-oil mixture by repeatedly freezing and thawing it while pumping off the gases as they evaporated out (Journal of Physical Chemistry B, vol 107, p 1714).
What he saw then was completely unexpected. “The mix spontaneously formed a cloudy emulsion. I was as surprised as anybody,” says Pashley. The result suggests that dissolved gas may be involved in how the force acts.
|
This means that we no longer have to use emulsifiers to keep water in suspension in fuel as means of increasing fuel mileage... boiling the water under a constant vacuum should suffice to remove enough of the dissolved gas to allow emulsification.