Monodisperse and polydisperse grades of silica nanospheres and microspheres are offered as free-flowing white powder and have an exceptional degree of roundness: >99%. Monodisperse nanospheres and microspheres in sizes ranging from 250nanometers to 8micron offer CV<10%. Polydisperse grades of silica microspheres offer a more economical option with D50=4-8micron and can be purchased with an optional dimethylpolysiloxane coating, which provides good dispersion and additional resistance to acids, alkalies, UV and moisture.
Silica microspheres are inherently hydrophillic and negatively charged. Aqueous suspensions of silica microspheres rarely require the use of surfactants or stabilizers. Silane coatings enable silica microspheres to be modified to generate functional groups or alter surface properties. Additional advantage of silica microspheres is glass transition temperature of over 1000 degrees Celsius, which makes them suitable for high temperature applications.