Improving the hydro-stability of MCM-41 by post-synthesis treatment and hexamethyldisilazane coating

Abstract

The stability of siliceous MCM-41 in various aqueous solutions including distilled water, 2-(N-morpholino)ethane sulphonic acid(MES) pH 6 buffer, tris-(hydroxymethyl)aminomethane (TRIS) pH 8 buffer and potassium phosphate pH 6 buffer is presented. The MCM-41 was hydrothermally-synthesised by sodium hydroxide (NaOH), cetyltrimethylammonium bromide (CTAB), fumed silica and distilled water. The structural stability of normal MCM-41 is compared to its stability after post-synthesis hydrothermal treatment alone and after post-synthesis hydrothermal treatment combined with coating with hexamethyldisilazane (HMDS). The combination of post-synthesis hydrothermal treatment and HMDS coating has the be..