Water Structure and Transport in Zeolites with Pores in One or Three Dimensions from Molecular Dynamics Simulations

Molecular dynamics simulations were carried out to explore the kinetic and structural properties of water diffusing through several types of zeolite with pore sizes that make them suitable for application as membranes for small ion filtering. Zeolites with pores in one and three dimensions were considered, and insights into the effect of the structures of the zeolites were obtained by studying diffusion and ordering of the confined water. Interestingly, water molecules in the zeolites with pores in one dimension showed up to 2.5-fold higher diffusivities than in those with pores in three dimensions for a given water density and a similar pore diameter. The distribution of water molecules across pores and the number of water molecules in a specified region were also investigated to determine the effects of pore shape and size on the water assembly. The arrangement and the number of water molecules in a cluster were observed to depend heavily on the shape and size of pores. The present study provides a deeper understanding of how various structural features affect the dynamics and structure of the water within zeolites