2015/07/14 by Salvador Rodríguez-Gómez Balestra, Salvador R. G. Balestra, Said Hamad +8 · 53 citations
Chemistry · Environmental Science · Physics and Astronomy · #Aluminosilicate #Catalysis #Chemical Synthesis and Characterization #Chemical physics #Chemistry #Composite material #Computational chemistry #Confined space #Crystallography #Diffraction #Distortion (music) #Materials science #Metal-Organic Frameworks: Synthesis and Applications #Metastability #Molecular dynamics #Nanopore #Nanotechnology #Optics #Phase (matter) #Physics #Slippage #Tungsten #Zeolite #Zeolite Catalysis and Synthesis #cond-mat.mtrl-sci #physics.chem-ph
paper · pdf · open access · doi:10.1021/acs.chemmater.5b02103
published in Chemistry of Materials 27(16), 5657-5667 (American Chemical Society)
openalex publication_date 2015/07/14 · arxiv created 2016/05/20 · arxiv updated 2016/05/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Molecular valves are becoming popular for potential biomedical applications. However, little is known concerning their performance in energy and environmental areas. Zeolite RHO shows unique pore deformations upon changes in hydration, cation siting, cation type, or temperature–pressure conditions. By varying the level of distortion of double eight-rings, it is possible to control the adsorption properties, which confer a molecular valve behavior to this material. We have employed interatomic potentials-based simulations to obtain a detailed atomistic view of the structural distortion mechanisms of zeolite RHO, in contrast with the averaged and space group restricted information provided by diffraction studies. We have modeled four aluminosilicate structures, containing Li +, Na +, K +, Ca 2+ cations. The distortions of the three different zeolite rings are coupled, and the six- and eight-membered rings are largely flexible. A large dependence on the polarizing power of the extra-framework cations and with the loading of water has been found for the minimum aperture of the eight-membered rings that control the nanovalve effect. The calculated energy barriers for moving the cations across the eight-membered rings are very high, which explains the experimentally observed slow kinetics of the phase transition as well as the appearance of metastable phases.