Hydrophobic fumed silica

AEROSIL® fumed silica—product groups

Hydrophobic fumed silica
AEROSIL^® grades	BET surface area [m²/g]	Loss on drying [wt.%]	pH	Carbon content [wt.%]
AEROSIL^®R 972	110 ± 20	≤ 0.5	3.6‑5.5*	0.6‑1.2
AEROSIL^®R 974	170 ± 20	≤ 0.5	3.7‑4.7	0.7‑1.3
AEROSIL^®R 104	150 ± 25	-	> 4.0	1.0‑2.0
AEROSIL^® R 106	250 ± 30	-	> 3.7	1.5‑3.0
AEROSIL^® R 202	100 ± 20	≤ 0.5	4.0‑6.0	3.5‑5.0
AEROSIL^® R 805	150 ± 25	≤ 0.5	3.5‑5.5	4.5‑6.5
AEROSIL^® R 812	260 ± 30	≤ 0.5	5.5‑7.5	2.0‑3.0
AEROSIL^®R 812 S	220 ± 25	≤ 0.5	5.5‑7.5	3.0‑4.0
AEROSIL^® R 816	190 ± 20	≤ 1.0	4.0‑5.5	0.9‑1.8
AEROSIL^®R 7200	150 ± 25	≤ 1.5	4.0‑6.0	4.5‑6.5
AEROSIL^®R 8200	160 ± 25	≤ 0.5	> 5.0	2.0‑4.0
AEROSIL^®R 9200	170 ± 20	≤ 1.5	3.4‑5.0	0.7‑1.3
AEROSIL^® R 711	150 ± 25	≤ 1.5	4.0‑6.0	4.5‑6.5

* Narrower pH possible, depending on region.
The data represents typical values.

Hydrophobic fumed silica
AEROSIL^® grades	BET surface area [m²/g]	Chlorides [ppm]	Water-dispersible Fraction [wt.%]
AEROSIL^® R 972 Pharma	110 ± 20	≤ 250	≤ 3.0

Numerous grades of hydrophobic AEROSIL^® fumed silica have been developed to solve particular technical problems. AEROSIL^® hydrophobic fumed silica are produced by chemical treatment of hydrophilic grades with silanes or siloxanes. In the finished product the treatment agent is chemically bonded to the previously hydrophilic oxide. AEROSIL^® hydrophobic products are characterized, among other things, by a low moisture adsorption, excellent dispersibility, and their ability to adjust rheological behavior, even that of polar systems.

AEROSIL^® grades such as R 7200, R 8200 and R 9200 undergo additional structural modification which makes it possible to offer further support to our customers in the development and enhancement of their products. An example of this would be higher loading levels in liquid systems with little impact on viscosity.

Positive effects:

Optimum rheology during processing
Thickening of polar liquids, e.g. epoxy resins
Reinforcement of silicone elastomers
High levels of loading, e.g. molding compounds
Excellent water-repelling properties, leading to improved corrosion protection
Improvement of dielectric properties, e.g. in cable compounds
Free-flow of powders, e.g. in fire extinguishers
Increased scratch resistance, e.g. in paints and plastics