Characterization of a gel-derived silica intended for use as a reference material

A new candidate surface area and pore volume reference material is proposed. A mesoporous gel-derived silica monolith has been investigated by nitrogen sorption and mercury intrusion porosimetry. BET specific surface area (165.5 m2 g−1), specific pore volume (0.986 cm3 g−1) and mean pore radius (11.9 nm) have been monitored for up to 12 months by nitrogen sorption. No significant changes occurred following either storage or repeated usage. The pore volume measured by mercury intrusion is in excellent agreement despite significant compression. The pore structure remained unaltered despite multiple mercury intrusion cycles up to high pressure. This remarkable stability and durability confers properties that compare favorably with those of commercially available reference materials. The primary advantage of the gel-silica monolith is the elimination of errors associated with powder sampling.