Sciencemadness Discussion Board

Emulsifiers

Arkada - 5-11-2021 at 04:11

Hello.
This is my first post, so I might be missing a proper topic for Q&A, but my quesition is:
do emulsifiers in general (soap, vitamin E, tween, etc) prevent solvent extraction?
Eg is it possible to use water emulsion as a reaction solvent for non-polar liquids and then extract products with organic solvent?

Metacelsus - 5-11-2021 at 07:21

If you're doing an extraction with aqueous and organic phases, surfactants/emulsifiers will be a big problem. It might be possible to get around this by using an ionizable surfactant and after the reaction is complete, adjusting pH out of the range where it works well as a surfactant.

RustyShackleford - 5-11-2021 at 13:27

while the presence of emulsifiers does not generally affect the concentration equilibrium between the phases, it will ofc cause a tremendous hinderance in the actual physical process of separating the two.

as for your second question, its indeed possible, and already being applied in some reactions. microemulsions (worth researching, not as simple or obvious as one may think) are being applied to reactions where normally phase-transfer-catalyst is used. the organic solvent domains have such a huge surface area it makes catalyst to transport between the two phases unnecessary, also increses reaction rate significantly.

Arkada - 6-11-2021 at 04:12

Thanks for help!