Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: GregJ7 on March 10, 2020, 11:25:10 AM
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I searched the forums for "hand sanitizer" expecting to get a lot of hits. I'm surprised at how little there was. I have always enjoyed making common home product myself. I would like to make some hand sanitizer for family use. I've had an interest in this for a few years since I noticed the high price (to me) of hand sanitizer some years after its initial popularity. In spite of potential anti-bacterial additions, my understanding is that ethanol is the primary active ingredient and is sufficient for the job. I want to shoot for 60% ethanol in the final product.
To prevent too much drying of the skin (for those that use it frequently), having some skin care properties is desirable. To make it easier to use (and not pour out of one's hand), a thickener is desirable.
I have tried dissolving various substances with Everclear (where I live it is 75.5% alcohol and water for the rest), but am surprised at how poorly they dissolve at room temperature. I have tried:
1. arrowroot powder
2. a cosmetic product that is 99% aloe vera gel
3. raw cocoa butter (at a temperature above its melting point but less than ethyl's boiling point)
I found a comment online that xanthan gum would dissolve in both oil and water, but it is expensive for me to do a 5 minute test only to see it fail. The common thickener in the commercial products I have seen is a form of a carbomer, but I haven't been able to uncover any info about the type used or its properties to know if it would dissolve in the ever-popular home chemical process of "stirring them together." It appears to be the popular choice for commercially-made gels for external hand use.
Presumably, the more thickening power the better (as long as it is cosmetically non-toxic), because it means more skin-friendly ingredients can be added such as aloe vera or cocoa butter (shea butter, etc.).
Does anyone know what non-toxic thickeners will dissolve in Everclear? A suspension would be insufficient for various reasons.
Thanks for any help you can give!
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You can use polyethylen glycol 10000 - 20000.
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glycerol?
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If you figure it out, let us know. Going price right now is something like $4Billion an ounce, so I hear. :/
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Glycerol is a good idea. I wish I'd thought of it! I had some and tried it out. By volume I ended up with 60.4% ethyl alcohol, 19.6% water, and 20% glycerin. It wasn't thick enough to prevent it from dribbling out of one's hand, however, it worked well as an extended for some (rather thick) hand sanitizer I had on hand.
It might work if I start out with 95% or 99% ethyl instead of 75.5% ethyl. It would allow me to add more glycerine and still maintain 60%+ ethyl. I'll have to look into how costly it is. (Everclear is cheap.)
Anyone know what "carbomer" is used for hand sanitizer, and/or the process is for dissolving it in 75.5% ethyl + 24.5% water?
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Problem with glycerol is that you want your sanitizer to evaporate or leave no residue. I don't know that glycerol with do that.
Re: Carbomer. It's a trade name for PAA: https://en.wikipedia.org/wiki/Polyacrylic_acid
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I noticed the residue when I tried it; it wasn't that bad, but after using hand sanitizer I think people, me included, would want a completely clean feeling.
Thanks for the info about Carbomer being polyacrylic acid, and in this case, the common one seems to be sodium polyacrylate. I was able to find a lot more information about it and it looks ideal, so I have ordered some to try.
*In my previous post, I meant "extender," not "extended."
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O yes, Covid-19...
The World Health Organization recommends soap, but nevertheless, hydroalcoholic gel is in huge demand as if it were magic. Unobtainable in France for instance. Making some at home is hence a big temptation.
The scarcity results from regulations essentially. Producing at home looks an interesting initiative. Distribution may be hampered by law. Not my problem here.
For a gel, most patents cite polyacrylate.
Though, the WHO recommends, as a substitute for soap if no drinking water is available, a home-made liquid rather than a gel. I've found it in French, not in English:
https://www.who.int/gpsc/5may/tools/system_change/guide_production_locale_produit_hydro_alcoolique.pdf?ua=1
For 10L according to that source:
- 8.3L of 95% ethanol or 7.5L 99.8% isopropanol
- 0.42L of 3% peroxide
- 0.15L 98% glycerine
- Rest distilled or boiled cooled water
Mix, wait 3 days before use.
The ethanol must be pure, free of methanol and other poisons added to rubbing alcohol. The peroxide is the usual pharmacy concentration - more concentrated could become very dangerous. Glycerine is often 85% concentrated.
Glycerine serves to protect the skin. This proportion won't make a gel. That's better, because I dislike the feeling of a gel after washing my hands. Thickening by glycerine would need >90%, and then <60% alcohol loses the antiseptic effect.
I would not use ethanol and peroxide regularly on my hands. Soap is better.
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I ordered PAA from two different sources, one finely ground, and the other coarsely ground which I subsequently ground fine with mortar & pestle. I also tried Arrowroot. None of these dissolved with room temperature or mildly microwaved temperature and vigorous mixing. Xanthan Gum showed signs of dissolving, although the next day it had mostly fallen out of suspension. It may have been partially dissolved and hours of constant mixing might more successful. I didn't try it.
The simplest successful use I've had is extending commercially prepared hand sanitizer with Everclear. The sanitizer brand I tried it with was so thick that there was hardly any noticeable viscosity change from topping off a 75% full bottle with Everclear. Going 50%/50% would have worked fine.
I am left wondering what process is used to blend the PAA with the ethyl, but don't care enough to investigate further.
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Re: Carbomer. It's a trade name for PAA: https://en.wikipedia.org/wiki/Polyacrylic_acid
Yes and no, mainly no. Carbomer 940 the typical thickener used in commercial formulations is a co-polymer of acrylic acid cross-linked with other monomers. It is a b$*%( to dissolve without high shear mixers etc.
Standard polyacrylic acids will not work.