Relevant parameters for obtaining high-surface area materials by delamination of magadiite, a layered sodium silicate
Résumé
Layered silicates can be used for the preparation of high surface area materials by intercalation with organic cations followed by ultrasonication. The relevant parameters for delamination (exfoliation) of cetyltrimethylammonium bromide exchange magadiite are investigated. Using a magadiite wet cake, performing the delamination in water and recovering the solid phase by acidification allow increasing the surface area of the final material by a factor of ca. 20 (553 vs. 30 m2 g−1) compared to the standard procedure. The role of each step is analysed and the material resulting from the optimised procedure can be described as creased silicate layers. This results in a microporous-mesoporous material with about 60% of the surface in pores larger than 2.0 nm.