Sciencemadness Discussion Board

Breaking a stable emulsion

khourygeo77 - 8-11-2021 at 17:36

Hello,

I have been struggling in breaking a tough type of emulsion. The emulsion consists of this: Alcohol, water and plant extract. When I make a herbal tincture or herbal alcohol distilled liquor (which contains alcohol, water and volatile herbal compounds), then I dilute with water, I get a turbidity and a cloudy water.

Heating and cooling, or even distilling doesn't manage to break the emulsion. Adding salt or even sugar in the aim of changing the densities after making the dilutions doesn't solve the problem as well

Any ideas? I know centrifuging is a possibility. But for the moment, I cannot afford to do that.

Thanks for your time

BromicAcid - 8-11-2021 at 18:54

You hit the big ones, adding sugar/salt will adjust the polarity as well, have you tried adding more alcohol? You can add something that's more non-polar like pentane that might help break it. Otherwise you're left with physical manipulations like vacuum cycling or mechanical vibration. Those are some of my go-tos when all else fails. Well, that and changing the solvent but then it's not really a tincture anymore.

arkoma - 8-11-2021 at 19:30

a vibrating dildonic device. seriously. hold it against side of sep funnel.

SWIM - 8-11-2021 at 20:10

Sometimes you can break emulsions like that by filtering.

In Industry they'd use a pressure filter, but vacuum filtering through a Buchner funnel has worked for me in some cases.

Try to avoid pulling such a high vacuum that the filtered solution starts to boil, as that may just make a new emulsion.

However are you sure the herbal extract is soluble in the dilute solution?
If your extract contains oils which go out of solution on dilution then the filtration will not make a valuable contribution.

If solubility is the problem then you'll probably have to use a higher alcohol content to keep things clear.

Are you familiar with Raki?
The way it gets cloudy when diluted is a good analogy for what I'm talking about.
The anise oil goes out of solution and forms a suspension when the alcohol level gets too low.

If you're not familiar with Raki, the Greek beverage Ouzo does the same thing.

EDIT: I'm not sure if I get what you're trying to achieve here.

Do you just want a clear solution, or are you hoping to separate the oils from the solution?

If the latter is the case, can you use a nonpolar solvent to extract them?


[Edited on 9-11-2021 by SWIM]

khourygeo77 - 9-11-2021 at 00:29

Quote: Originally posted by BromicAcid  
You hit the big ones, adding sugar/salt will adjust the polarity as well, have you tried adding more alcohol? You can add something that's more non-polar like pentane that might help break it. Otherwise you're left with physical manipulations like vacuum cycling or mechanical vibration. Those are some of my go-tos when all else fails. Well, that and changing the solvent but then it's not really a tincture anymore.


Alcohol is the problem here. Adding it will stabilize the emulsion.

The only reason I cannot separate the oils is because they are so attached to the alcohol, in solution and in distillation..

I tried adding hexane to a hydroalcoholic tincture, it partially worked. But it didn't work at all when I tried to extract the oils out of the distilled alcoholic liquor..

Can you provide more info about the cited physical manipulations like expected prices and which devices I can use and how they work? I am a complete amateur about this stuff...

Thanks

khourygeo77 - 9-11-2021 at 00:44

Quote: Originally posted by SWIM  
Sometimes you can break emulsions like that by filtering.

In Industry they'd use a pressure filter, but vacuum filtering through a Buchner funnel has worked for me in some cases.

Try to avoid pulling such a high vacuum that the filtered solution starts to boil, as that may just make a new emulsion.

However are you sure the herbal extract is soluble in the dilute solution?
If your extract contains oils which go out of solution on dilution then the filtration will not make a valuable contribution.

If solubility is the problem then you'll probably have to use a higher alcohol content to keep things clear.

Are you familiar with Raki?
The way it gets cloudy when diluted is a good analogy for what I'm talking about.
The anise oil goes out of solution and forms a suspension when the alcohol level gets too low.

If you're not familiar with Raki, the Greek beverage Ouzo does the same thing.

EDIT: I'm not sure if I get what you're trying to achieve here.

Do you just want a clear solution, or are you hoping to separate the oils from the solution?

If the latter is the case, can you use a nonpolar solvent to extract them?


[Edited on 9-11-2021 by SWIM]


The herbal extract's oils form a stable emulsion with the dilute solution. However, some sediments get separated and fall down but it is mainly some waxes and other stuff. My aim is to separate the oils as they form a very tight bond with the alcohol

Filtration will not help.

I am very familiar with Raki. I tried it on similar alcoholic beverages but the oils will never get out of solution no matter how much I dilute the liquor. My aim is to break the suspensions and separate the oil from the alcohol

Non polar solvents don't work at all on distilled liquors but partially work on herbal tinctures.

SWIM - 9-11-2021 at 00:45

If you just want the volatile oils you could try steam distillation of the plant material.

This is common practice for making essential oils, but in some cases takes a lot of steam.

Or how about evaporating the tincture to a viscous fluid, dissolving in a non-polar solvent, and extracting with water to remove the water soluble elements.

Could you tell us what you're extracting/trying to get?

khourygeo77 - 9-11-2021 at 02:00

Quote: Originally posted by SWIM  
If you just want the volatile oils you could try steam distillation of the plant material.

This is common practice for making essential oils, but in some cases takes a lot of steam.

Or how about evaporating the tincture to a viscous fluid, dissolving in a non-polar solvent, and extracting with water to remove the water soluble elements.

Could you tell us what you're extracting/trying to get?


I know how to extract essential oils by using different methods. But this method interests me more because it will allow me to use much less heat or energy.

The essential oil sticks to the alcohol so well. If I try to evaporate it, the essential oils will evaporate as well as the alcohol. They form an azeotrope.

I just need to know how I can break the bond between alcohol and essential oils. My purpose is to find a new type of extraction (different from hydrodistillation, steam distillation, CO2 extraction etc).

The extraction's exact aim is to to separate essential oils from an alcoholic solution. I believe there must be a very simple solution (whether chemical or physical...)

BromicAcid - 9-11-2021 at 04:46

Agree with SWIM, have seen filtrations break emulsions several times.

Fantasma4500 - 9-11-2021 at 08:14

ultrasonic vibrations may help seperate the emulsions
otherwise, try with DCM? distills over at 40*C and you can always flush the DCM out of plant material using water

maybe check reagents and acquisition, one guy just posted about making his own centrifuge

khourygeo77 - 10-11-2021 at 13:47

Quote: Originally posted by Antiswat  
ultrasonic vibrations may help seperate the emulsions
otherwise, try with DCM? distills over at 40*C and you can always flush the DCM out of plant material using water

maybe check reagents and acquisition, one guy just posted about making his own centrifuge


I cannot store DCM appropriately. And what really interests me is to break the ethanol & oil bonding.

Can you provide more info about ultrasonic vibrations? This seems interesting but I don't know from where to start (what device I need to use, how expensive it is...). I'd need to generate some very loud sounds?

khourygeo77 - 10-11-2021 at 13:49

Quote: Originally posted by BromicAcid  
Agree with SWIM, have seen filtrations break emulsions several times.


What kinds of filtrations? There are many types..

BromicAcid - 10-11-2021 at 15:09

Usually shoot it through a 0.25 micron encapsulated using nitrogen pressure. Really just depends on what you have.

khourygeo77 - 10-11-2021 at 15:24

Quote: Originally posted by BromicAcid  
Usually shoot it through a 0.25 micron encapsulated using nitrogen pressure. Really just depends on what you have.


Chemistry isn't exactly my domain so I don't understand exactly what you mean. Using 0.25 micron porous material might make it work you mean?

Btw. Chromatography might work but I am not sure

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7398001/

I tried all methods except for chromatography. I guess I'll need to do some research because I couldn't grasp if it works or not, and if there can be a material capable of only adsorbing the alcohol without the oil...

khourygeo77 - 10-11-2021 at 16:13

"The human body is composed of around 100 trillion cells. Essential Oils are composed of around 40 million trillion molecules per single drop! How can so many molecules fit into a single drop? They are extraordinarily small, which enables them to pass through all of our tissues and directly into our cells."

I wonder if there is a procedure that allows separation of mixtures by molecule size?

Chromatography & Molecular sieves might work. Also, the methods chemists use in research papers to identify volatile compounds in wine should work as well..

[Edited on 11-11-2021 by khourygeo77]

[Edited on 11-11-2021 by khourygeo77]

clearly_not_atara - 10-11-2021 at 20:43

Idea: replace the ethanol with glacial acetic acid, extract into GAA, add to water and neutralize with NaHCO3 or similar.

walruslover69 - 10-11-2021 at 21:55

you could extract with pentane and evaporate to yield your oil

Fantasma4500 - 18-12-2021 at 04:14

as for ultrasonic, it was just an idea. cheaper devices can only run 5 minutes at a time

if you want some bulk solvent, go for gasoline, distill it. i got some fractions coming over at about 40*C, they stank quite a bit though
and i got a decent amount also up to 60*C
at about 110*C you will get toluene, thats what you wanna avoid as solvent because it stinks really bad

Monoamine - 18-12-2021 at 08:49

This does not sound like an emulsion to me...
If your solution becomes turbit when adding more water it most likely means that your phytochemical are not water soluble. In that case you should be able to extract them out using a non-polar solvent.

In fact, if it is an emulsion the you can extract the ethanol out of the emulsion by simply extracting the emulsion itself with a nonpolar solvent that is very miscible with ethanol but not with water (for instance ethyl acetate). This will also extract the ethyl acetate-soluable phytochemicals from your emulsion.

Also why do you need a tincture? If you have dried powdered extract then you should also be able to dose it better if it's for consumption.

Do you have a picture of the emulsion?

karlos³ - 18-12-2021 at 11:54

Just pull it through a pad of celite in the frit.
Emulsion = gone.

Maybe pull it directly into a funnel, because "re-frothed" emulsions(just invented the word re-frothed!) tend to emulsify up again in the joseph funnel(sorry thats an inside joke.... we call one of ours "Sepp" which stands for joseph actually in bastard/bavarian german, and in consequence we had to call the sep funnel joseph funnel :D).

Organikum - 21-12-2021 at 15:17

An older textbook says that filtration through a plug of fine glasswool (lab glasswool which is much finer then the one for insulation) breaks virtually every emulsion. There are glassfiber filters available which do about the same.

Be every careful with the application of vacuum as too much reintroduces the emulsion.

On the other hand I discovered that gravity filtration through a N95 mask (cheapest kind available, just hang it in a plastic funnel) is rapid and works splendidly in removing even very fine particles and also any kind of emulsion like when so often you have a turbid layer of organic solvent on the water phase you can either wait, and wait, and wait or just pour the whole shebang through a N95 and miraculously end up with two clear layers calling for instant separation.
The masks take on some liquid and must be squeezed dry after use (or cut a circle and use with a tiny bit of vacuum) but thats the only issue I discovered.

I also propose that the middle layer of the masks, one alone or several put together is the the long searched for OTC membrane for electrolytical processes of all kind, filling the gap between obnoxious flower pots and salt-plugs and Nafion XYZ membranes doped with unobtainium hemisulfate.


/ORG