December 22, 2024, 10:53:04 PM
Forum Rules: Read This Before Posting


Topic: SODIUM METASILICATE turning into gel?  (Read 9058 times)

0 Members and 1 Guest are viewing this topic.

Offline robron

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
SODIUM METASILICATE turning into gel?
« on: May 15, 2009, 02:16:00 AM »
I am in the process of formulating a low pH detergent with high cleaning ability. the formula is as follows, water,sodium metasilicat(andro),STPP and sodium hydroxide.  once blended the formula seems to stay in solution, however the moment i try to lower my pH it starts to turn into gel at around 9.5 and then when i add my solvents and surfactants, it splits!

Does anyone have any info on how to keep metasilicat in solution around pH 8!

thanks

Rob

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7976
  • Mole Snacks: +555/-93
  • Gender: Male
Re: SODIUM METASILICATE turning into gel?
« Reply #1 on: May 15, 2009, 03:20:06 AM »
Metasilicid acid shows pKa1 about 10 and below this pH precipitation of H2SiO3 take place.
AWK

Offline eugenedakin

  • Oilfield Consulting Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 658
  • Mole Snacks: +88/-2
  • Gender: Male
  • My desk agrees with the law of entropy
    • Personal Website
Re: SODIUM METASILICATE turning into gel?
« Reply #2 on: May 17, 2009, 07:22:31 PM »
Hello robron,

Sodium metasilicate needs to be present in excess of caustic.

You may want to try a different chemical that is stable at this pH.

Best wishes,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

Offline robron

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
Re: SODIUM METASILICATE turning into gel?
« Reply #3 on: May 19, 2009, 08:58:32 PM »
Thank you for your response! greatly appreciated!

Do you have any other ideas? I have tried Phosphates STPP and TKPP! But still no where near metasilicates performance.

Thank you once again

Offline eugenedakin

  • Oilfield Consulting Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 658
  • Mole Snacks: +88/-2
  • Gender: Male
  • My desk agrees with the law of entropy
    • Personal Website
Re: SODIUM METASILICATE turning into gel?
« Reply #4 on: May 20, 2009, 08:27:14 PM »
Hi robron,

With all of the potential aspects of sodium metasilicate, which property do you want to substitute? If it is the caustic portion, then substitute caustic soda. If it is the abrasiveness, then add finely ground calcium carbonate.

Thanks for answering my question,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

Offline 408

  • Chemist
  • Full Member
  • *
  • Posts: 796
  • Mole Snacks: +103/-30
Re: SODIUM METASILICATE turning into gel?
« Reply #5 on: May 20, 2009, 09:07:52 PM »
Metasilicid acid shows pKa1 about 10 and below this pH precipitation of H2SiO3 take place.

That is not the reason for gel formation however...  protonation of metasilicate allows acid catalyzed sol-gel synthesis to occur, and gel formation is resultant from the crosslinked Si-O-Si polymer network forming.  Not from precipitation of a discreet species.

Offline robron

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
Re: SODIUM METASILICATE turning into gel?
« Reply #6 on: May 21, 2009, 12:38:13 AM »
ok so to get this right!

Any contact with any acid will result in gel formation or (SI-O-SI)! is this correct?

As the reply from eugene! as far as i know the reasons for Sodium Metasilicates are, Firstly as a high alkaline base(which i can sustitue with caustic) Cleaning aid,Emulsifier,Defloculant,Soil suspension and prevent soil deposition!

I really appreciate the advice from you all!

Thanks


Offline eugenedakin

  • Oilfield Consulting Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 658
  • Mole Snacks: +88/-2
  • Gender: Male
  • My desk agrees with the law of entropy
    • Personal Website
Re: SODIUM METASILICATE turning into gel?
« Reply #7 on: May 27, 2009, 08:15:46 PM »
Hi robron,

In summary, yes, lowering the pH with acid will form gels.

As for the other properties, do you need to have all of these, or are some properties more important than others?

Sincerely,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

Sponsored Links