Sunday, April 14, 2013

Weekend Wonderings: Adding surfactants to emulsified scrubs, solidification points of powdered surfactants, where to find SLS in Canada, and substituting surfactants

In this post, Experiments in the workshop: Black cocoa butter emulsified sugar scrub, Stephany writes: Could I incorporate a little bit of surfactant in this to make it foamy???And in this post on facial scrubs, Stephany offers a potential recipe. (Click to see it.)

An interesting thought, but no, you can't add surfactants to a product that is all oil. Firstly, we don't want to add water to anything with salt or sugar in it as it will dissolve them, which means you might end up with a solid chunk of stuff in the bottom of your container. This also means you need a preservative that works with water soluble ingredients.

And secondly - and the bigger issue - oil and bubbles do not mix, so adding surfactants will do nothing. Adding as much as 10% oils to a body wash or shampoo can completely destroy the bubbles and lather, so having as much as 70% oils will mean you won't even notice the surfactants exist! I suggest instead that you check out one of the nice surfactant based scrubs we made and add a few oils to that!

Related posts:
Facial scrubs: Using the surfactant base to make scrubs - part 1
Using water in salt or sugar scrubs
Answering e-mails: Salt or sugar in water based scrubs

In the Weekend Wonderings comment post, 7slaper asks: My weekend wondering is about surfactants, to be precise the "clouding" point of liquid surfs. (like the titer point of oils) Let's say I buy liquid DLS (INCI Disodium Lauryl Sulfosuccinate, aqua) with a concentration of 65%. It is clear as water. I ran out of the liquid, so decided to make it myself: 65% powdered DLS in water. When heated the solution was clear; cooled down to room temp (20°C): clear as well, but afer a few days it became cloudy and after two weeks it looked like a bottle of milk! Disappointment all over. :(

I tried this with other surfs, like SLS for a household product. Results are the same. I think only the 5% solution is still clear after some months. You are the surf guru Susan; Any ideas why this happens?

I don't think of myself as a surfactant guru - more an enthusiast with an eye to becoming an acolyte then maybe a guru! But I'm on my way up the ladder! :-)

As for the cloud point of surfactants, I have written about it in a few places briefly... The important of temperature - an example and titer points - but I think the key is more about the solidification point of our surfactants rather than the titer point. Liquid surfactants will have cloud points whereas powdered surfactants have solidification points or temperatures.

Check out this data sheet on Bioterge AS-90 (powder), which is C14-16 olefin sulfonate (same as Bioterge AS-40, only this is a powder. You can find it at Voyageur Soap & Candle, which is where I found the picture). As you can see, the appearance of this product at 25˚C is "off white, free flowing beads". If you dissolve this powder in water, when it reaches around room temperature it might return to this state. Liquid C14-16 olefin sulfonate has a cloud point of 7˚C or 45˚F, so it'll become cloudy at those temperatures. The powder will become solid at a temperature much higher than that.

They are the same ingredient - both AS-40 and AS-90 are C14-16 olefin sulfonate - but they are in different states with one being liquid, one being solid. I don't think you can make a liquid version of it without cloudiness. If you're trying this with your powdered surfactants at home, don't forget that the moment you add water to something - preferably distilled water - you must add a broad spectrum preservative.

I chose C14-16 olefin sulfonate as I have experience with both the liquid and solid ingredient. I realize 7slaper is asking about DLS sulfosuccinate, but I haven't worked with that powder. 

Michelle asked in an e-mail if I knew where to get SLS in Canada. Sorry, I don't. I know where to get SLSa - which you can find as Lanthanol in some places. You can get it at Voyageur Soap & Candle, Aquarius, Creations from Eden (I think), and many other locations. Look for SLSa or Lanthanol. (Always know your INCI for the product as well - find it here!) I know you can get it at Brambleberry in the States, but that wasn't the question!

What difference will using SLSa cause in your product? I don't know as I've never used SLS and it will depend upon the product. If you're making bubble bars, I think it should be the same, but you may need to increase the cream of tartar to make the bar harder. In shampoo bars, it doesn't seem to make a difference. And you could use Bioterge AS-90 powder in the product instead. I've tried my favourite bars with AS-90 and I quite like them, although I did find them a little too degreasing for my tastes when coupled with the liquid. (As above, AS-90 and AS-40 are both C14-16 olefin sulfonate.) The kids in my youth program loved them, but I thought they made my hair greasier too quickly! I didn't notice a difference in the hardness of the bars.

Substituting one surfactant for another might result in a small change, a larger change, or no change at all! Each offer different things to the product, so I suggest checking the surfactant chart or surfactant section of the blog to ensure you are getting what you want. For instance, switching C14-16 olefin sulfonate for decyl glucoside changes a lot, including foaming, lathering, bubbling, cleansing, and thickening properties. Some surfactants thicken well with salts and things like Crothix, others don't.

If you find a recipe on the blog that calls for Bioterge 804, be advised this is hard to find. Instead, read the INCI for the ingredient - look at this post - and figure out what you might buy instead. I'm afraid I don't know the ratios, but a search at Stepan (the manufacturer) might help with this!

I can go into greater detail about substituting surfactants if that interests anyone! 

And if you are writing to me to ask about a surfactant based thing, you must include your entire recipe and process if you want me to help you figure out what you've done. Telling me you followed my recipe exactly can't possibly be true as you aren't going to do everything exactly the way I did it. And maybe I'm the one who screwed it up by writing something down incorrectly! Please make it easier for me to help you!

Do you have a comment or question? I check all the comments on the blog every day, but it would be kinda nice if we could keep them in one place like this Weekend Wonderings comment page! Get on over there and share your wonderings!


Stephany&Stacia said...

Oh wow Susan, thank you for this, I feel so honored that my question was good enough to appear on your blog! lol :) Thanks for everything, keep up the good work!

Anonymous said...

Knowing how busy you are, I'm just so glad to see people talking about playing with chemistry! No matter what you write, it's interesting. Thank you.

Katherine Chiu said...

I would love to know how to substitute surfactants. I can't possibly buy all of the different ones that out there. I'd like to have 2 or 3 top performers to choose from. It would be fabulous if you would cover that topic! Thank you for all that you do.

Lucy Townsend said...

Loving the whipped butters..hoping to have the time soon to experiment.. Hope you don't mind a question on surfactants, I'm still trying to formulate a sensitive scalp shampoo. I am trying to enhance foaming and thickening product, otherwise I'd have to use a ton of guar gum.. I've been looking at formulations in the uk and coco glucocide seems to be used in organic formulations, and ultra sensitive products, I couldn't find this on your blog so wondered if it goes under another name.
Otherwise, I'll next try sci. Not sure which is considered to be milder??
Many thanks

7slaper said...

Thank you so much for your answer Susan. :) And excuses for my late reaction; the flu got the better of me. :(

I think it finally dawned on me!

The powdered surfs don't truly dissolve in water :D
I assumed it was a matter of saturation (compare sugar or salt - seeing salt crysals on your skin when you dry up after having a swim in the sea or honey in which the sugar crystalizes).

This explains the "miracle" of shampoo - which only contained 10% powdered SCI - I made in summer some years ago. It was clear at first at RT, but the next morning the shampoo was opaque, then again when the temp went up, it became clear again. :D

Liquid SCI is still on my wish list

Thanks again, you're the best!

Aljonor said...

Hey Susan:

Wholesale Supplies Plus has a free recipe on adding surfactants in an scrub; however, she is using the melting and pour soap and a foaming whip. Below is the link.
it is called Debbie's "Best Ever" Gingerbread Scrub.