Spontanious nucleation of LTA Zeolite
Simulation of the formation of the LTA framework.
- 648 SiO4 monomers
- 27 SDAs r = 4.64ÅE_O_bind = -0.67 kcal/mol
- 27 SDAs r = 6.88ÅE_O_bind = -0.34kcal/mol
- Volume =144 x 144 x 144Å
There is a repulsion between the SDAs so they won’t approach each other much closer then their expecteddistances in the zeolite we are trying to make
We start with all the particles randomly distributed over the simulation volume.At first small oligomers are formed especially around thesmallerSDAs as themonomerconcentration is a bit higher here due to the attraction.Next to the small SDAs these oligomers subsequently form rings and partial cages as monomers continue to accumulate from the solution.
These partial cages are now large enough that they start to have a significant attraction around the larger SDA.This starts the formation of the large cages. Over time the small clusters coalesce to form larger LTA crystallites.
The total run time of the simulation is about 25 ns and the calculations were performed in LAMMPS.
