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AEROSIL® R 812 S

1 of 33 products in this brand
AEROSIL® R 812 S is hydrophobic fumed silica grade treated with HMDS (Hexamethyldisilazane). It is even more hydrophobic than AEROSIL® R 812 and convenient for stabilizing a defoamer and well suitable as a component of foam control agents.

INCI Name: Silica Silylate

Chemical Name: Silica gel, pptd., cryst.-free

Functions: Anti-Caking Agent, Rheology Modifier, Thickener, Viscosity Modifier

CAS Number: 112926-00-8

Chemical Family: Silica

Safety Data Sheet

Knowde Enhanced TDS

Identification & Functionality

Chemical Family
CASE Ingredients Functions
CAS No.
112926-00-8
EC No.
601-214-2

Features & Benefits

Benefit Claims
CASE Ingredients Features

Applications & Uses

Application Format
AP/Deo Applications

Properties

Physical Form
Physico-Chemical Properties
ValueUnitsTest Method / Conditions
Tamped Density (ex plant)approx. 60g/l
Specific Surface Area (BET), Multipoint195 - 245m²/g
SiO₂ Content (based on ignited material)min. 99.8wt %
pH Value (in 4% dispersion)5.5 - 9.0ISO 787-9
Loss on Drying* (at 105 °C, 2 hours)max. 0.5wt %ISO 787-2

Regulatory & Compliance

Certifications & Compliance

Technical Details & Test Data

Sedimentation Stability of Defoamer Formulations

To prepare the model defoamer formulations, 2 weight-% each of the silica products listed above were incorporated in a mixture consisting of polyethersiloxane (38 weight-%, TEGO 5861, Evonik Goldschmidt GmbH and mineral oil (60 weight-%, ONDINA® 913, Shell). For incorporation of the silica we used a rotor-stator system Ultra-Turrax® at 10.000 rpm for 1 minute. The quality of dispersion and the sedimentation stability of the defoamer formulations obtained was recorded at intervals of 7, and 31 days and 6 months by means of a) microscopic evaluation and /or b) rheological measurements (see Figure 2 and 4) and subsequently visual inspection.

Figure 2 Methods used for evaluation of the dispersion and sedimentation stability of the model defoamer formulation a Microscopy for checking the quality of the dispersion b Rheology for viscosity measurements

AEROSIL® R 812 S - Sedimentation Stability of Defoamer Formulations

Figure 3 Sedimentation stability of hydrophobic AEROSIL* and SIPERNAT® containing model defoamer formulations. The higher the number of an isoline, the more stable the model defamer formulation is expected to be against settling. The relative position of the black dots in this and the following figures represent the same silica grades as shown in Figure 1

AEROSIL® R 812 S - Sedimentation Stability of Defoamer Formulations - 1

On the other hand, the rather hydrophobic precipitated silica products SIPERNAT® D 10 and SIPERNAT® D 17, the structure modified fumed silica grades AEROSIL* R 9200 and AEROSIL R 7200, and the slightly hydrophilic AEROSIL* R 816 are located in the upper (green and blue colored) part of the diagram in Figure 3. They are therefore not expected to have sufficient sedimentation stability in the tested model defoamer formulation. Combinations of precipitated and fumed silica may improve the stability of the formulation considerably; however, this is beyond the scope of this brochure and will be explored in the future.

Every black dot represents the same silica grade as shown in Figure 1. The higher the number of an isoline, the more stable the respective model defoamer formulation is expected to be against settling. For example, a silica grade positioned in the red or yellow area means that the model defamer it is based on should have very good or good sedimentation stability. The following hydrophobic AEROSIL* fumed silica products were actually found to have good or very good sedimentation stability:

Packaging & Availability

Country Availability
Packaging Type
Regional Availability
  • North America