摘要 |
<p>Silicon dioxide powder in the form of aggregated primary particles has a specific pore length L of 2.5×105 to 4×105 m/mug, where L is defined as the quotient formed from the square of the BET surface area and the cumulative 2-50 nm pore volume determined using the BJH method, as per the formula L=(BET×BET)/BJH volume. A silanized silicon dioxide powder in the form of aggregated primary particles has a specific pore length L of 2.5×105 to 3.5×105 m/mug, and in it the surface area of the aggregates or parts thereof is occupied by chemically bound silyl groups. A thermal insulant comprises the silicon dioxide powder and/or the silanized silicon dioxide powder.</p> |