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Zustand: New. In English.

Zustand: New. The behavior of water in silicalite and dealuminatedzeolite Y (DAY), two highly hydrophobic zeolites,was investigated at different temperatures in therange 100-600 K by molecular dynamics simulationsusing the Compass forcefield. The full flexibilityof water.

Taschenbuch. Zustand: Neu. Neuware - The behavior of water in silicalite and dealuminatedzeolite Y (DAY), two highly hydrophobic zeolites,was investigated at different temperatures in therange 100-600 K by molecular dynamics simulationsusing the Compass forcefield. The full flexibilityof water molecules and the zeolite framework wasconsidered. The results show that the behavior ofwater is more complex in silicalite than in DAY.Three different activation energies for waterdiffusion were obtained in silicalite in the range250-600 K compared to two for DAY. The values ofthese activation energies are discussed in detailand are related to the strength of hydrogen bondsand the zeolite structure. From the radialdistribution functions (RDFs), it is shown thatwater mostly exists in the gas phase at roomtemperature in silicalite, whereas liquid-like wateris observed in DAY. The self-diffusion coefficientsof water and the RDFs were obtained as functions oftemperature in order to explain the differentbehaviors of water in the two all-silica zeolites.The influence of loading on the self-diffusioncoefficients also was investigated for both crystals.…