Simply pure

Colloidal silica

We produce colloidal dispersions of silica particles in water under the trade name Köstrosol®. The particles are made from high-purity alkali silicate. They are spherical and generally non-crosslinked and are hydroxylated at the surface.

The reactivity of our colloidal silica can be modified and changed according to their target application. The binder effect or the polishing properties of the materials can therefore be adjusted precisely.

For the optimum choice of material, select your product from our colloidal silica portfolio or tell us your specific application. We are happy to develop a product according to your specific application properties.


To find perhaps the ideal product that suits your application you have two options.

You can use also the filter below, to search directly for your application. If you couldn't find your application or a product doesn't meet your requirements or you need a consultation, then please contact our staff who will be happy to help.


Product data


  • Particle sizes from 3 to 100 nm
  • Silica concentrations from 7 to 50%
  • Specific surface area 40 to 800 m²/g (according to Sears)
  • Application-specific modifications (e.g. ammonium-stabilised, aluminate-modified, cationic etc.)
  • Definable particle size distributions (narrow, broad, monomodal or bimodal etc.)

Example applications:

  • Binders in ceramic compounds for high temperature applications
  • Clarification of wine, beer and fruit juice concentrate
  • Polishing agents in wafer and memory-chip production
  • A component of silicate-based paints and plasters
  • Retention aids in papermaking


The trade name of our silica sols contains two pairs of digits to represent the basic properties of the materials:

  • The first pair gives the average particle diameter (in nm).
  • The second pair gives the solids content in mass%.
  • Letters in the name refer to special modifications (e.g. AS for ammonium stabilised).