Conversion of O/W to W/O - Chemists Corner

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Conversion of O/W to W/O

Posted by ssdc on March 16, 2015 at 2:20 am

Dear All,

I came across a formulation using both w/o and o/w emulsifier to form the emulsion. And it claims that the initial state of the emulsion is o/w but after applying the phase transform to w/o, thus leaving a residue on the skin.

I tried searching for materials on this but cant find any. Do any of you here knows the chemistry behind this phenomenon

Thank you

ssdc replied 9 years, 1 month ago 3 Members · 3 Replies
3 Replies

MakingSkincare

Member
March 16, 2015 at 4:00 am

Many chemists use the hlb system, using a low HLB (w/o) emulsifier paired up with a high HLB (o/w) emulsifier to create an emulsification system eg o/w. (You can read more about this and download a calculator here - http://www.makingskincare.com/hlb-calculator/ )

When the product is applied to the skin there is much shear force applied which will re-emulsify the product. The water level in the emulsion will drop so the emulsion turns an O/W emulsion to a W/O emulsion. Then it will leave an oily film as the water evaporates further.
gangarani

Member
March 16, 2015 at 4:34 am

@Making skincare thanks a lot for the link..(HLB)..
ssdc

Member
March 16, 2015 at 10:14 am

@makingskincare thank you for the information.

I would like to know if I am only using 1 type of emulsifier (either w/o or o/w emulsifier) will the phase transformation still takes place? If this still takes place then in a normal o/w emulsion I assume the water still evaporate right?

On the other hand, for a w/o emulsion the water is in the inner phase can it be evaporated easily?

I hope you can help me in this

Thank you

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