Fumed Silica is type of white, non-toxic, odourless and amorphous inorganic fine chemistry products which is made of the chlorosilane with the pyrohydrolysis under the oxy-hydrogen flame state.
Fumed SiO2 (CAS number 112945-52-5), also known as pyrogenic silica because it is produced in a flame, consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles which then agglomerate into tertiary particles.
Fumed SiO2 can be divided into hydrophilic type and hydrophobic type in accordance with their different surface treatments.
Properties | Unit | Typical Value | Standardization |
/ | / | 200 | / |
Specific surface area (BET) | m2/g | 200±25 | GB/T 20020-2005 |
pH-value in 4% dispersion | m/m % | 3.6~4.5 | ISO787-9 |
Loss on drying ( 2h @ 105ºC) | m/m % | ≤1.5 | ISO787-2 |
Loss on ignition(2h @ 1000ºC,based on material dried for 2h @ 105ºC) | m/m % | ≤2.5 | ISO3262-1 |
Sieve residue (45μm) | m/m % | ≤0.05 | ISO787-18 |
Tamped density (based on material dried for 2h @ 105ºC) | g/L | 25~60 | ISO787-11 |
Silica content (based on ignited material) | m/m % | ≥99.8 | ISO3262-20 |
Carbon content (based on material dried for 2h @ 105ºC) | m/m % | ≤0.2 | ISO3262-20 |
ferrum dioxide content | m/m % | ≤0.003 | ISO3262-20 |
Corundum content | m/m % | ≤0.05 | ISO3262-20 |
titanium dioxide content | m/m % | ≤0.03 | ISO3262-20 |
Applicaton:
Fumed SiO2 serves as a universal thickening agent and an anticaking agent (free-flow agent) in powders. Like silica gel, it serves as a desiccant. It is used incosmetics for its light-diffusing properties. It is used as a light abrasive, in products like toothpaste. Other uses include filler in silicone elastomer and viscosity adjustment in paints, coatings, printing inks, adhesives and unsaturated polyester resins. It is also used in the production of cat litter box filler.
Fumed Silica 150: it is mainly used for acidic silicone rubber, RTV silicone rubber (low moisture content) and neutral silicone rubber
Fumed Silica 200: it is mainly used for high-temperature vulcanized silicone rubber, organic silicone defoamer, advance printing ink, powder coating, PVC resin, unsaturated polyester resin thickening, thixotropic agent, pharmaceutical powder, tabular preparation, cosmetics etc.
Fumed Silica 380: it is mainly used for silicone rubber, silicone grease and sealing materials of capacitance packaging with high transparency and high tear resistance.