This is interesting and vast topic and text books have been written on this..

However, read this review, its a good start.

dx.doi.org/10.1016/j.cis.2009.10.003

mix a solvent whose CMC value is very high or can be broken by electrochemically.

Mechanisms of Stability of Oil-in-Water and Water-in-Oil emulsions are different. When water face if Continious, Stability follows DLVO theory. When Oil Phase is Continious, tails of natural surfactants in Crude Oil are responsible for high stability.

In the case Oil is Ashphaltenic, WATER-IN-OIL Emulsion is really very stable, separation becomes the problem.

Matt is right. As water solubility in oil is not zero, the KELVIN effect works with emulsions. Smaller droplets are getting dissolved and water molecules are getting tranported intu Larger Droplets. This mechanism of destabilization is on the finer molecular level and beyond Colloidal Stability.

Fellows ! Is any one can clear stabilization effect due to hydration forces ?

Thanks, MATT, this line of reasoning is known to me. As a matter of fact I was one of the authors of the paper dealing with the Theory of ELECTRIC DOUBLE LAYER, accounting for HYDRATION FORCES (JCIS, 1978 ). But some people are claiming HYDRATION EFFECT coused by H -bond, etc., never providing theoretical explanation, nor experimental data. But may be I have missed something. I tried to post this question on RG, but redactor nulifies my attemts, my computer skills are low.

Please, POST This question on my behalf, let's see what people know on the subject. Thanks, Alex.

Sure, thanks, Matt. NINHAM runs this whitch-craft for decades. No theory and no valid experiments.

Thanks for information, Matt. I had in mind Hydration of Inorganic Ions only. But that is fine to work on more complicated cases as well.

MATT, please, lookk at my CV on this website. 2 papers were published in JCIS, 1978.

The first author is Y.GUR, he was my PhD student at the time.

Sure, MATT, we help one another, thank you and thanks to this RG network. Keep in touch, my e-mail is [email protected]

Regards from Holy Land,

Alex

Sure, Rey, Laurie SCHRAMM is the great expert in Surfactants and their Applications to Oil Recovery. Just a year ago Laurie and I published paper on the subject: " OSMOTIC REPULSION FORCE DUE TO ADSORBED SURFACTANTS". You may find this paper helpful. It is posted in full on my RG site, the very first paper.

Of, couse, Ray, I am happy to help younger scientists. I worked for over 20 years at the ALBERTA RESEARCH COUNCIL, CANADA, Heavy Oil Department. As the Heavy Oil is always Ashphaltenic, the WATER - IN - OIL Emulsions were extremally stable. But we lacked QUANTITATIVE MECHANISM for this great STABILITY. About year 2000 Dr. SCHRAMM, at the time ARC Vice-President, Energy, pressed me to provide theoretical solution of the problem, but I failed. It came to me as a vision some 11 years later, as I retired and moved South. I informed Dr. SHRAMM of the result, he immidiately supported Eq.5 as in the paper, so we spent next 2 month writing this paper. I was lucky that he did not lose interest, as he is a busy person, President of the SASKATCHEWAN RESEARCH COUNCIL.

Thanks for your interest,

Alex Babchin

I wish you success, Ray. When I was under 50, I had the complex of small, insufficient knowlege. I don't have it anymore, but I am over 70 ! So, don't worry, you have time.

Keep in touch, Ray, I am happy to share my experience. Alex.

I have e-mail supported by remote server in Russia: [email protected]

So, Ray, no traces of my current location are visuble by any big brother.

I was born in Russia under Comrade Stalin, he was big FATHER.

Kind regards, Alex

Reasons for coalescence in o/w and w/o are the same.

Of coarse thermodynamically both are unstable. Insufficient stabilization leads to high probability of coalescence. For o/w stabilization is not necessarily of electrostatic origin. In a lot of cases it is provided by nonionic surfactants.

Interestingly it was found that in case of insufficient stabilization coalescence happens in the moment when droplets detach after they have approach each other.