To begin dry all glassware in the oven for at least two hours before use. To ensure a moisture free surface. Store the aminosilane DAS within a septum capped lid bottle.
Consider the appropriate DAS loading to increase the probability of the aminosilane. Locating the silanol groups on the silica for covalent bonding. Add the desired amount of silica support in a round bottom Schlenk flask equipped with a magnetic stir bar.
And insert a rubber septum into the reaction vessel before removing air and moisture from the vessel connected to the Schlenk line. First open the reaction vessel's stopcock to connect it to the vacuum for about 30 seconds. Then close the stopcock, switching to an inert gas supply for another 30 seconds.
Insert a line of inert gas into the septum capped lid bottle containing anhydrous toluene. Use a gas tight syringe to draw the desired amount of toluene and purge the syringe with inert gas. Before removing the solvent from the bottle, ensure the magnetic stir bar inside the reaction vessel is stirring smoothly, and puncture the septum on the reaction vessel with the gas tight syringe containing the anhydrous toluene, and transfer the toluene into the vessel.
After removing the inert gas needle from the toluene, change the needle head. Then, as demonstrated previously, transfer the desired amount of DAS to the reaction vessel. Use an adapter to attach a line from the Schlenk apparatus to a water condenser with the help of vacuum grease.
Wrap the bottom of the condenser apparatus with polytetrafluoroethylene or PTFE tape, and attach a septum to the bottom of the condenser. After subjecting the line to vacuum and inert gas cycle three times, attach the condenser apparatus to the round bottom Schlenk flask. Then attach the cold water lines to the water condenser and turn on the water circulation.
Lower the reaction vessel into a silicone oil bath at a temperature of 80 to 100 degrees Celsius. Close the stopcock to the inert gas on the round bottom Schlenk flask, and leave the stopcock on the condenser open. Stir the reaction while heating for six hours.
After that cool the reaction vessel to room temperature. Next, connect the Erlenmeyer filer flask to the vacuum via a hose. Place a rubber bung at the opening before placing a Buchner funnel on top of the rubber bung.
After placing a filter within the Buchner funnel, wet the filter with anhydrous toluene. Switch on the vacuum before quickly dispensing the solution onto the filter to collect the solid grafted amine silica on filter paper. Rinse the collected material three times with about 10 milliliters of anhydrous toluene.
Using a clean, dry laboratory spatula, transfer the white grafted silane material from the filter paper to a vial. After covering the vial with punctured aluminum foil, place it in a vacuum oven and turn on the vacuum. Set the oven to about 100 degrees Celsius.
And allow to dry for approximately 18 hours to remove excess toluene.
