Thursday, February 24, 2011

Fun with chemistry: Anionic, cationic, and non-ionic

Will writes....I'd love to learn more about the whole _____ionic thing and how it applies to lotions/cream, etc. I've read about it, and the more I read the more confused I become. How about dumbing it down and explaining it in your excellent fashion? Just wishing...

Wish no more, Will! When it comes to chemistry, you ask and I will write (and it's not just 'cause flattery works well with me!).

Anionic, cationic, and non-ionic refer to the charge on the ingredient in question. Non-ionic means it has a neutral charge. Anionic means it has a negative charge. And cationic means it has a positive charge.

Take a look at this picture. The head is the thing that carries the charge. If the charge on the head is negative - for instance, something like sodium laureth sulphate with a sodium ion on the head - it will be an anionic ingredient.

If the charge on the head is positive - for instance, something like BTMS-50 - it will be a cationic ingredient.

If the head carries both a positive and negative charge, we get a zwitteronic ingredient (something like our betaines or sultaines, which are also called amphoteric when we're talking about surfactants), which can be positive or negative depending upon the pH level of the product.

This chart really only applies to our surfactants, those with a hydrophilic head and a hydrophobic or lipophilic tail (not just bubbly surfactants, but anything that reduces the surface tension between the two phases of our products, like emulsifiers). If it doesn't fall into the category of surfactants, then we generally have a non-ionic ingredient.

Most of our foaming, bubbling surfactants are anionic or negatively charged. Quaternary cationic compounds like BTMS-50, cetrimonium chloride, cetrimonium bromide, and Incroquat CR, and cationic polymers are positively charged.

In lotions, most of our ingredients are non-ionic or neutrally charged, like our emulsifiers, fatty alcohols (like the cetyl alcohol molecule you see), fatty acids, oils, butters, extracts, hydrosols, humectants, and so on. So when it comes to lotions, we're dealing mostly with non-ionic ingredients.

You can add a cationic ingredient to a lotion - I do it all the time with things like cationic polymers (like polyquat 7, polyquat 10, polyquat 44, and honeyquat) or as our emulsifier, like Incroquat BTMS-50. Cationic ingredients are substantive, meaning they will adsorb to your hair or skin and are substantive. (For more information on substantivity, please click here.) You can add an anionic ingredient to a lotion, but I can't think of any I'd like to add (for instance, I really don't see adding something like SCI to a lotion, despite my love for it!)

You really don't need to worry about charges all that much when it comes to lotions because most of our ingredients are non-ionic and we can easily add some cationics to the mix without fear of any serious problems.

Why add cationic ingredients to a lotion or cream? Generally we add them to a lotion for the skin conditioning benefits (the whole substantivity thing). When we use Incroquat BTMS-50 as our emulsifier or add a cationic polymer to our lotions, we are increasing the skin conditioning features of the lotion (and in the case of honeyquat, we're also adding a humectant, so it's a bonus!)

As an aside, I've said this before but please indulge me for a moment. You cannot have a hair conditioner without a cationic ingredient. The very essence of a conditioner is that it adsorbs to the hair strand and offers substantivity. Without a cationic ingredient, you don't have a conditioner. You might have something else that your hair likes, but it isn't considered a conditioner. 

Do you have chemistry related questions? Ask away! And for more chemistry, please check out the "frequently asked questions" post to the right hand side of the blog!


Jillian said...

Wow, great post!

Heidi said...

hmm.... I am wondering if this is a chemistry question. But I have been wanting to ask, so here goes.

I want to extract the goodness out of different a tincture. Now I know that people use different mediums, like Alcohol, vinegar, and oil. Each is suppose to extract different things from the herbs.

My question is this. I want to use this extraction on the scalp. Oil would be out, too greasy. Would alcohol strip hair of hair dye? Would vinegar also strip the hair dye? I have read too many conflicting reports.

If they do strip the dye, can you suggest a different medium that would be ok for hair and scalp but would also extract the goodness of the herbs.

I thought about water, but not sure if that would get all the goodies. Plus might be a nightmare to preserve.

Hoping this is a chemistry

Thank you!

Will said...

I kinda get it. Even though I said lotions, I think you read into my thoughts a little bit.

I've cautiously been thinking about expanding into a few of the surfactant cleaners, especially your fake cetaphil facial cleanser or spectro-gel (distressing my "natural" soapmaking self).

I'd already be dabbling if there was a local supplier where I could travel to on a whim. Planning takes so much of the fun out of things.

Thanks for the education!


Tara said...

To make a note on Heidi's question: you can also make an extraction using glycerin (known as a glycerite). Some hair types would like glycerin :)

Frank (and family) said...

Thanks, we've wondered about this, too.

Anonymous said...

Hi, I don't have chemistry background; while I am doing a DIY serum. The product flyer of one ingredient says that cationic emulsifier system should be avoided. I would like to know if any of these emulsifiers is of cationic: Olive Oil PEG 7 Esters (PEG -7 Olivate); Cromollient SCE & Polysorbate 80.

Thanks for your advice in advance!

Susan Barclay-Nichols said...

Hi Anonymous! You can find information about all of those emulsifiers by looking at the bath & body guide to ingredients on my blog (look to your right for the list) or by looking in the emollients/esters list in the "links to lists" sections of the blog.

PEG-7 olivate can emulsify things, but I wouldn't consider it an emulsifier because it's very very limited. It's considered an ester or water soluble oil.

Anonymous said...

Hi Susan,

Thanks for your prompt reply!

I was introduced to your blog by my friend 3 days ago; as what she said, your blog was very informative and you're a great source of DIY.

Keep up your good works so that we can get benefits from your knowledge!

SuperSparrow said...

Hi, Susan. Your posts have been so helpful to me as a progressing newbie to the DIY lotion world. I was wondering if you're familiar with Sodium Behenoyl Lactylate as an emulsifier. I've been experimenting with it and Behenyl Alcohol based on some recipes in the Herbarie's formulary. It's listed as "slightly anionic". How will this effect my formulations and the coditioning power of my lotions?

bala4787 said...

Great Explanation. Hope you could help with my problem.

I am using a anionic wetting agent with my flux for soldering, tinning , brazing of copper and copper alloy(Metal Surface)
My wetting agent dry out at high temperature, resulting in improper joining. My operating temperature is 250Centigrate to 320 C.

Which type of wetting agent to use Anionic, Cat-ionic or Non Ionic or Zwitterionic.

Is a wetting agent with such high boiling point which in inflammable available?

Thank you

Susan Barclay-Nichols said...

Hi bala. I have no idea, sorry. This is a blog for cosmetic chemistry.

Diva Soap said...

Hi Susuan,
I had asked this ealirer, but never got a response from you. Unfortunatelly, I can't find my answers neither on the net, nor from cosmetic experts on forums and groups. So, I will ask one(last)time more- what anionic emulsifier brings to (or takes out from)the lotion. How it differs from the same lotion made with anionic emulsifier? There are numerous suppliers selling Lanette N, but none provide this kind of info, but someone must be buying and using this emulsifier,:-)!? How substantial is the electric charge of an emulsifier for a lotion?
Thank you, if you respond and thank you if you don't (I believe you still have to read this)!

Susan Barclay-Nichols said...

Hi Diva. Sorry, I can't find another comment from you about this topic, so it must have quite some time ago or it's lost in the ether.

There are so many different things an emulsifier brings to a lotion, it's hard to say that this one is anionic so it brings "x" and this one is non-ionic so it brings "y". We use the emulsifier for the skin feel, viscosity, emulsifying abilities, and so on. So I can't say that because Polawax is non-ionic it does this and because Lanette is anionic it does this because there's so much more that happens with the inclusion of the fatty alcohols or the other emulsifiers we use and so on.

I don't know anything about Lannette L as I can't find it locally and haven't used it. You'll have to ask someone who has used this and another emulsifier to see how it compares.

The main thing we worry about when it comes to anionic, non-ionic, and cationic is compatibility. If you're using an anionic ingredient, you don't want to use cationic ingredients and vice versa. When you use non-ionic ingredients, it doesn't tend to matter that much.

Diva Soap said...

Oh thanks for replying, Susan! You wrote about Lanette N (not L) in this post, where I also wrote a comment. That's why I asked you about this emulsifier.
So, basically, I'm safe to use it as long as I don't use any cationic ingredient.
Thanks again for your time and answer!

Ala ud din Jutt said...

Nice post. I like it. This is useful for me. I have more knowledge about it at:

Ange Bunch said...

Would you know what the surfactant is in JetDry rinse aid (for dish washers)? Is surfactant the main component of a rinse agent? And would I be able to buy it somewhere? I've combined some household products and created an amazing shower/tub cleaner, but I'd like to just use the active ingredient from JetDry rather than JetDry itself in my concoction.
Thanks so much.

Susan Barclay-Nichols said...

HI Ange. Sorry, I have no idea, although a quick Google search did turn up quite a few interesting pages. It sucks that we can't easily get information about the ingredients they use, eh? Even if I didn't want to replicate the product, it'd be nice to know what's in it!

I don't make suggestions about household products as it's really easy to destroy a washer or dishwasher with the wrong ingredients. Oh, it won't happen the first or even the tenth time, but when a friend of mine had to replace her expensive front loading machine after a mere two yeras because she was making her own detergent, I vowed to not get involved in that kind of formulating.

Renee Ng said...

Hi Susan,
I hv encountered a problem when making a cream facial cleanser. I know that basic lotion is in fact already a cleanser per se, but I would like to add some lathery quality into it. I used 25% oil phase which includes 6% emulsifier (and I am using olivoil Emulsifier which is an Non-ionic emulsifier) . Well everything was nice and neat before adding the surfactant ( I use 12% POTASSIUM COCOYL GLYCINATE), but once I added in the surfactant , everything separated. The "lotion" became watery again. In the end I needed to add xanthan gum to thicken it up

1)Could you pls tell me the reason behind ?
2) And if I really wanna add some lathery quality into the cream cleanser, what can I do?
Thanks a lot

Renee Ng said...

Hi Susan,
I hv encountered a problem when making a cream facial cleanser. I know that basic lotion is in fact already a cleanser per se, but I would like to add some lathery quality into it. I used 25% oil phase which includes 6% emulsifier (and I am using olivoil Emulsifier which is an Non-ionic emulsifier) . Well everything was nice and neat before adding the surfactant ( I use 12% POTASSIUM COCOYL GLYCINATE), but once I added in the surfactant , everything separated. The "lotion" became watery again. In the end I needed to add xanthan gum to thicken it up

1)Could you pls tell me the reason behind ?
2) And if I really wanna add some lathery quality into the cream cleanser, what can I do?
Thanks a lot

Susan Barclay-Nichols said...

Hi Renee! Can you please post your exact recipe in percentages and process so I can help you further?
Why not try making a surfactant based product to which you add creaminess instead of trying to add lather to a lotion? Just a thought...

Renee Ng said...

Hi Susan, I used the followings:
Oil phase 25% 5g
✓ 6% 1.2g Castor oil
✓ 5% 1g Sweet Almond oil
✓ 5% 1g Coconut oil
✓ 4% 0.8g Shea butter
✓ 5% 1g olivoil Emulisifer
Heated Water phase 66% 13 g
✓ 21% 4.2g Distilled water
✓ 20% 4g Rose water hydrosol
✓ 6% 1.2g 15drops Glycerine
✓ 4% 0.8g Methylglycerine
✓ 3% 0.6g Hydrolysed silk protein
✓ 12% 2.2g potassium cocoyl glycerine
✓ Citric acid
Cool down phase 9.1% 1.8g
✓ 3% 0.6g 12 drops chamomile extract
✓ 2% 0.4g 8 drops NMF
✓ 1% 0.2g 4 drops seaweed extract
✓ 0.5% 1 drop Lavender oil+1 drop Rosemary oil
✓ 2% 0.4g 10% diluted potassium sorbate
✓ 0.6% 0.12g phenoxyethanol.
It failed and then I tried again using very simple ingredients to find out where went wrong and I used the followings:
1) 19% Shea butter
2) 6% olivoil emulisifer
3) 54% water
4) 12% potassium cocoyl glycerine
And I didn't proceed to the cool down phase as it became watery again once I added the surfactant

Could u pls tell me the reason behind?
And how to add creaminess to the cleansing product?
Thx so much for your reply !

Denise Van Winkle said...

Susan, I recently switched out emulsifying wax nf for btms 25 in my grape seed lotion. I felt the ew nf was too waxy and the btms 25 just has a nicer feel.

However, even after letting the lotion settle, after putting it in containers and tapping it down, the containers expand, and the lotion foams out. The lotion hasn't gone bad-I know about that all too well. All is well when using the btms 25 in conditioner, or when using the emulsifying wax nf in the lotion.

I thought it was because btms 25 is cationic, but now I think that's not it. The recipe is:

Distilled water 39%
Coconut water 39%
BTMS 25 7%
Grape seed oil 15%
Germall Plus Powder Preservative .2%

I'm at a loss as to why it's foaming up only with this formulation.

I hope you might have some insight.

Thanks Susan!