Home Cosmetic Science Talk Formulating Fumed silica and yellowing?

  • Fumed silica and yellowing?

    Posted by beautysci on August 11, 2015 at 8:02 pm

    I have been trying to make a clear lip scrub using a fumed silica gellant. However, all versions yellow significantly at 45C. I have a hunch it is the fumed silica, because I read somewhere that small sized silica can contribute to some yellowing in formulas. 

    Has anyone experienced yellowing of a clear product with fumed silica? 
    Thank you for your help. 
    David08848 replied 8 years, 8 months ago 5 Members · 6 Replies
  • 6 Replies
  • Bobzchemist

    Member
    August 11, 2015 at 8:42 pm

    Does it yellow without the fumed silica? What about using precipitated silica?

  • Chemist77

    Member
    August 12, 2015 at 5:33 am

    @Bobzchemist Are there any fixed standards to make a choice between the two?????? Or the formulation can accommodate both depending on the final properties desired???? 

    I have used Aerosil 200 in my lip gloss (clear) with good suspension of large glitter particles and it was based on Indopol H100 among other things from Scher esters. To tell you frankly it had a good suspension effect in that anhydrous formulation. 
  • Bobzchemist

    Member
    August 12, 2015 at 3:30 pm

    Precipitated silica is a scrub/abrasive ingredient. Fumed silica is a suspending/thickening ingredients, that is useless as a scrub, due to it’s ultra-small particle size. By trying the formula with precipitated silica, it should be possible to determine if there’s a problem with silica generally, or just with the fumed version.

    Precipitated and fumed, by the way, are referring to how the silica is manufactured.
  • Chemist77

    Member
    August 13, 2015 at 3:47 am

    @Bobzchemist Thanks that makes everything quite comprehensible. But that raises another question, do you need to suspend precipitated silica since it is just an abrasive???

  • kot

    Member
    September 4, 2015 at 8:01 pm

    Can fumed silica be used in hair serums?

  • David08848

    Member
    September 4, 2015 at 8:21 pm

    I purchased a quantity of fumed silica a few years ago and when we moved last year I found it again, portions of the top of the bag had turned quite a shade of deep yellow while the rest remained white so that may just the nature of the beast whether it is in a formula or left on its own over time.  I need to get rid of it but need to know where…

    David

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