摘要 |
<p>Amorphous silicas having a crystalline appearance, at least two surfaces in symmetric relation, a length of about 1 to about 500 mu and a thickness of about 50 A to about 1+82, the length being at least about 10 times the thickness, the amorphous silicas being in the form of primary particles, secondary particles, aqueous dispersions of the particles and shaped bodies.</p> |