Home Cosmetic Science Talk Formulating Thickening oil with silica dimethyl silylate

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  • Thickening oil with silica dimethyl silylate

    Posted by JonahRay on January 11, 2021 at 9:07 pm

    Hi friends! I’m trying to thick an oil consisting of equal parts squalane, CCT, and octyldodecanol with silica dimethyl silylate. Sometimes and not always I get a bit of seperation of the product. One of the oils seems to come out of the gel. I’m thinking it’s octyldodecanol but does anyone have any thoughts about silica dimethyl simulate and its compatibility with these 3 emollients?

    JonahRay replied 3 years, 10 months ago 2 Members · 10 Replies
  • 10 Replies
  • ngarayeva001

    Member
    January 11, 2021 at 9:41 pm

    It doesn’t perform well with high polarity oils (the one I have is covasilic 15). I tried it in both octyldodecanol and CCT and it didn’t thicken them at all. I have not tried it in squalane, but it thickens hydrogenated polyisobutene. Since those two are both hydrocarbons and low polarity the thickening you see is probably due to squalane. And it is not surprising you see separation. Your oils have different polarities.

  • JonahRay

    Member
    January 11, 2021 at 9:46 pm

    It doesn’t perform well with high polarity oils (the one I have is covasilic 15). I tried it in both octyldodecanol and CCT and it didn’t thicken them at all. I have not tried it in squalane, but it thickens hydrogenated polyisobutene. Since those two are both hydrocarbons and low polarity the thickening you see is probably due to squalane. And it is not surprising you see separation. Your oils have different polarities.

    @ngarayeva001 Thanks for your reply! If I were to keep the same oil profile and add in an additional oil thickening agent like polyamide-3. Would it likely improve the situation? If not is there anything you would recommend?

  • JonahRay

    Member
    January 11, 2021 at 9:49 pm

    @ngarayeva001 or I also have polyhydroxy stearic acid

  • ngarayeva001

    Member
    January 11, 2021 at 9:52 pm

    Cannot guarantee as I have not tested that myself but usually C12-15 Alkyl Benzoate helps with mixing silicones and high polarity oils, so maybe adding some to your blend helps it to mix properly. Speaking of polyamide-3, I tried polyamide-8 and it thickens quite well on its own. I read polyamide-3 thickens better than 8, so try it without silica. Polyamide-3 should be suitable for medium to high polarity.

  • ngarayeva001

    Member
    January 11, 2021 at 9:55 pm

    Polyxydroxystearic acid is for dispersing pigments. It has some thickening properties but not much. It will also make your  oil blend cloudy. Btw, I had my eye on polyamide-3 for a while. Have you tried it? I wonder if it allows creating a transparent product? Polyamide-8 isn’t bad but it’s cloudy (and for non-polar oils)

  • JonahRay

    Member
    January 11, 2021 at 10:12 pm

    @ngarayeva001 I haven’t tried polyamide-3 on its own but I’ve used it in combo with silica dimethyl silylate. I’ll try to increase the level of polyamide-3 and hope for the best! It doesn’t seem to ALWAYS separate, just sometimes.

  • ngarayeva001

    Member
    January 12, 2021 at 12:12 am

    Even if it separates sometimes it’s a stability issue that needs to be addressed. Polarity should be considered when mixing oils. They all are very different.

  • JonahRay

    Member
    January 31, 2021 at 10:39 pm

    Okay so I tried thickening squalane and CCT with my silica dimethyl silylate and they both thickened really well. I don’t have any octyldodecanol left to try. I tried to thicken a blend of squalane and CCT with polyamide-3 but even at 10% polyamide-3 it was barely thickened and also very cloudy. So when the gel-balm is in an airless pump it remains together but as you pump it out it almost gets thicker like what settles to the bottom is thicker and heavier? If you are willing to help @ngarayeva001 I can send you the whole formula privately?

  • ngarayeva001

    Member
    January 31, 2021 at 11:30 pm

    sorry, I haven’t worked with polyamide-3 to make any assumptions. I actually should get it in two weeks, so if I discover anything useful I will post here. Again, if I have to guess, the issue you encounter is most likely due to polarity.

  • JonahRay

    Member
    February 1, 2021 at 2:11 am

    @ngarayeva001 okay sounds good! I do find it really annoying to melt - I have to bring everything up to like 100C before it melts completely or it’s just a bunch of sticky blobs. 

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