ABSTRACT
Nomenclature and Classification of Types . . . . . . . 188
Differences among the Types . . . . . . . . . . . . . . . . . 189
After-Treated Synthetic Amorphous Silicas . . . . . . 191
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Improvement of Mechanical Properties . . . . . . . 192
Rheological Additives . . . . . . . . . . . . . . . . . . . . . 192
Carrier Applications . . . . . . . . . . . . . . . . . . . . . . . 192
Surface Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Pigment Effects . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Electrical Effects . . . . . . . . . . . . . . . . . . . . . . . . . 194
Adsorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Use of After-Treated SAS for the Improvement
of Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Other Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Handling of SAS . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Questions Regarding Registration and Approval . . 197
Toxicology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Skin Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Peroral Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Pure synthetic silicon dioxide in powdered form is discussed. After a brief history, the significance of this
product group is shown by the total production quantity in the Western hemisphere. A clear classification
of synthetic silicas is given, and the principal differences between thermal and wet-process products are
illustrated. After-treated silicas are also discussed. Various applications of synthetic silicas are described
in detail. Questions about useful handling methods, registration, approval, and toxicology are addressed.