Nanoporous Materials: Pillared Clays and Regular Silicas as an Example of Synthesis and Their Porosity Characterization by X-ray Diffraction

Zr-PILC synthesis Two grams of a montmorillonite rich clay (for instance Bentonite CAS-No-1302-78-9) in 200 mL of water are stirred for a minimum of 2 hours, but preferably overnight. 50 mL of an aqueous 0.1 mol/L Zirconium(IV) oxychloride octahydrate (ZrOCl2·8H2O; CAS-No-13520-92-8) solution are then dropwise added to the clay dispersion (an isobaric dropping funnel can be used) under strong stirring. The mixture is then aged for 2 hours at 40 oC without stirring but under reflux, after which the solid phase is separated by centrifugation. Remove a small amount of solid for X-ray (the “Before washing” sample). Insert the solid in a dialysis tubing (example: cellulose membrane for retaining proteins of molecular weight 12000 or greater) that was previously boiled, close both sides of the tube and insert it in a container with distilled water (at least 500 mL). Keep in water preferably during a week and, occasionally, change with new water. After this time open the dialysis tube, remove the slurry and evaporate the water (use a rotary evaporator, but do not set the temperature above 60 oC). Remove a small amount of solid for X-ray (the “After washing” sample). Dry at 90-100 oC, put the solid in an alumina boat and calcined at 350 oC for 2-3 hours preferably in a open tubular oven or other type of oven that allows some degree of air to enter in it.