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Author: Subject: Neutral skin gel (soap)
pneumatician
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[*] posted on 12-9-2022 at 16:30
Neutral skin gel (soap)


Hi,

the best and simple recipe to make soap skin liquid gel, of around Ph 5.5. All with natural ingredients, nothing of exotic chemicals.

Maybe if a mix a acidic olive oil and sodium hydroxide looking the Ph... and stopping when reach the Ph of 5.5??? this end in a soap?? or in a disgusting soup?
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artemov
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[*] posted on 13-9-2022 at 01:25


I made liquid lye soap from KOH and olive/coconut/castor oil quite a few times. The final pH is always around 8/9.

Lye soap is basically the sodium/potassium salts of fatty acids hydrolysed from triglycerides by the strong base.
Reducing the pH will cause the fatty acids to separate out (protonated?), resulting in a disgusting and probably unusable soap.

From what I read, however, you can use citric acid to stabilise or reduce the pH by just a bit. Exposing it to air/CO2 (curing?) will probably reduce the pH too.

Although the skin's pH is around 5.5, alkaline soaps do not really affect the acid mantle (there's a study on this somewhere).



[Edited on 13-9-2022 by artemov]
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Lionel Spanner
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[*] posted on 14-9-2022 at 04:18


You need synthetic surfactants, e.g. sodium laureth sulphate, to make a neutral or acidic soap. Anything based on fatty acid salts becomes water-insoluble wax/oil when acidified.



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