Pressure-induced symmetry changes in body-centred cubic zeolites.

ABSTRACT: Previous work has shown a strong correlation between zeolite framework flexibility and the nature of structural symmetry and phase transitions. However, there is little experimental data regarding this relationship, in addition to how flexibility can be connected to the synthesis of these open-framework materials. This is of interest for the synthesis of novel zeolites, which require organic additives to permutate the resulting geometry and symmetry of the framework. Here, we have used high-pressure powder X-ray diffraction to study the three zeolites: Na-X, RHO and ZK-5, which can all be prepared using 18-crown-6 ether as an organic additive. We observe significant differences in how the occluded 18-crown-6 ether influences the framework flexibility-this being dependent on the geometry of

SUBMITTER: Nearchou A 

PROVIDER: S-EPMC6689579 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature