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Free keywords:
Dodecasil 1H; template; temperature program; crystal morphology; particle size
Abstract:
The synthesis of Dodecasil 1H was studied in the system SiO2/1-adamantylamin/NH3/water with the objective of controlling the particle size and the morphology of the crystals. Since nucleation occurs in a very early stage of the synthesis, the heating rate to the final temperature and/or holding points during heat up have a strong influence on both parameters. Crystals smaller than 150 μm could only be obtained by the use of seed crystals, which are completely consumed in the synthesis with subsequent new nucleation. Using seed crystals, the expensive template 1-adamantylamine can be substituted with cheaper reagents such as sodium dodecyl sulfate or trimethylethylammonium bromide and, in addition, by using certain heating rates the amount of additional template can be reduced to zero.
