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  • zno and ph in a lotion

    Posted by DrArlen on December 18, 2019 at 9:09 pm

    Good night, i am working on a lotion using 8percent or more zno. this zno is not coated with silica dimethicone or anything else. As i know the ph should be 7 or lower(5 or 6). I have used citric acid and metered the ph of lotion 5,7. 1 or 2 hours later i metered the ph of lotion 7,1. why it has increased. what should i do saving my zno becoming an anion. Please help me. I am accepting book suggestions of this topic too. Thank you a lot.

    DrArlen replied 4 years, 10 months ago 3 Members · 3 Replies
  • 3 Replies
  • MArchambault

    Member
    December 19, 2019 at 6:29 pm

    I think Zinc needs to be above 7.

  • chemicalmatt

    Member
    December 23, 2019 at 3:57 pm

    That much ZnO will not be soluble in any workable amount of acid; which you may only use acetic or mineral acids (e.g. HCl, HNO3) anyhow, so give up on solvating it, just disperse it in oils or paraffinics like everyone else does. That way, your pH is irrelevant.

  • DrArlen

    Member
    December 23, 2019 at 8:37 pm

    Yes i am dispersing in some parafins and oils as you say. If i do that way will not the zno be amphoteric. I want to adjust the ph below 7 at the end. when i want to adjust ph lower the 7, i need citric acid %2 and this makes the lotion more viscous.

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