One of the easiest ways to improve stability is to increase the dispersed water phase to >60%. This increases the viscosity of the emulsion due to internal phase packing. Using the correct emulsifier and level is also critical. I recommend starting with around 5% total emulsifier and reducing the level to the point of failure to help identify the optimal level.
Consider using combinations of polymeric and non-polymeric emulsifiers, since they normally work better. Modern polymeric emulsifiers have significantly improved the quality and stability of water-in-oil emulsions. They cover the emulsion interface better and have made it possible to easily incorporate up to 90% water. However, they migrate to the interface slower than monomeric types.
You also should use electrolytes in all w/o emulsions. Electrolytes help partition more emulsifier to the interface and help reduce the interfacial tension. Typically divalent electrolytes like Magnesium Sulfate work the best. I also like to homogenize all w/o emulsions to reduce the particle size. This typically is done when the emulsion is <50C. Be careful not to over homogenize, which can result in viscosity loss over time.
My favorite water in oil emulsifiers are:
(Click EU below for product listings in Europe.)
Polymeric
- Cithrol™ DPHS (PEG-30 Dipolyhydroxystearate-Croda) (EU)
- Dehymuls® PGPH (Polyglyceryl-2 Dipolyhydroxystearate-Evonik) (EU)
- ABIL® EM 180 (Cetyl PEG/PPG-10/1 Dimethicone-Evonik, good with silicones) (EU)
- ISOLAN® GPS (Polyglyceryl 4 Diisostearate Polyhydroxystearate/Sebacate- Evonik) (EU)
Non-polymeric
- Fluidanov 20X (Octyldodecanol, Octyldodecyl Xyloside- Seppic, works well with DPHS type of emulsifiers)
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Hi,
I have a question regarding increasing the dispersed phase water, to >60% to stabilize w/o emulsion. Don’t we see inversion (o/w instead of w/o) if we have >60% of water in the formulation?
Could you please suggest the percent of oil phase components in a formulation to have stable w/o emulsion?
Thank you
Hi, i might be on the wrong page. but i do need help pretty badly.
i am trying to make a perfect oil in water solution.
i am trying to make a White Carbol which consisted of Pine Oil, Citronella oil and surfactant.
I have been testing for 6 months and yet to find the best formulation.
1. i have 20mL of pine and 20mL of Citronella mixed. and then i added about 5mL of tergitol (NP-9) , it was perfect white and i thought i have succeeded in making a milky white emulsion. and so i added about 500mL of water and 200mL of CMC (thickening agent) and leave it overnight. i found out that my emulsion started to seperate badly. all the water at the bottom and about 1cm of white layer which i supposed to be the emulsion(i m nt too sure what is that). is it because i added so much water that destabilize the emulsion ? if so how do i make a 4L Carbol with 20ml of PIne oil and 20mL of Citronella oil ? please help
Hi there, I just come across this thread and I am hoping you can help. I am trying to make a cream using magnesium chloride. I have after many failures changed emylisfiers to olive 900, am I now able to put the dissolved mag flakes in the water phase or w i ‘ll I be best to add at the end once the w/o emulsion have f opened and cooled. Thanks so much
Most people use Magnesium Sulfate Hexahydrate (Epson salt) however Magnesium Chloride should also work..Salts need to be added before emulsification
Hi!
I trying to make a emulsion O/W let me explain mi problem:
Hi!
I trying to make a emulsion O/W let me explain mi problem:
I have 99.5 g corn oil and 4.1 g soybean lechitin mixed, then I try to make a emulsion with 95 mL water and 5 mL of first mixed. I can see a milk white emulsion, but after a 1 minute I see a cream layer. Somebody can hellp me to stebilize my emulsion?
I make a test with pH 6 and pH 4, but I can´t see changes
What emulsifers/coemulsifers do you recommend for formulating a water in oil emulsion solid stick/bar for hair conditioner?
My water is phase is not greater than 10% total weight.
Thank you
Dear Margaret:
Example emulsifiers to try include: Cithrol DPHS (PEG-30 Dipolyhydroxystearate-Croda), Cithrol PGTL (Tri(Polyglyceryl-3/Lauryl) Hydrogenated Trilinoleate-Croda) and Dehymuls PGPH (Polyglyceryl-2 Dipolyhydroxystearate-Evonik).
Thanks for reading!
George
Greetings please kindly assistance. ” The best way to stabilize this type of emulsion is to use around 2-3% low molecular weight polyethylene wax (MP ~80C) in the oil phase. – George Deckner”
If I use the MP-80C in the oil phase can I still use HLB emulsifier (Alacel – 1689) in the water phase mostly glycerin? Thank you
Dear Esther:
Water in oil emulsions require low HLB emulsifiers in the oil phase. High HLB emulsifiers in the water phase will create instability.
Thanks for reading!
George
Hi there, I need your help.
Last time, I try to make a w/o emulsion, where the oil phase consists of: 20% Span 80, 12% of PIBSA, 50% of mineral oil and 18% of paraphin wax. The W phase consists of 90% ammonium nitrate, 10 % water. The ratio between W/O phase is 93,5/6,5. But the emulsion is not stable after 2 months storage at ambient environment. So how do I improve the stability more than 6 months.
Thank you!
Dear Tri:
No, this sounds like something illegal. Ammonium Nitrate is used in explosives.
Thanks for reading,
George