Abstract
Mordenite was obtained in high yield from an aqueous hydrogel of composition 2.4 Na 2O . A1 2O3 . 11 SiO 2 . 219 H 20, left to crystallize in static Pyrex auto-claves at 165°C for 3 days. The progressive variation of pH and density of the liquid phase with synthesis time suggest that mordenite crystallites are grown at the expense of the solid hydrogel, through a liquid phase ion-transportation type mechanism. Coexisting phases such as analcite or various silica polymorphs appear with longer heating times. Combined bulk (EDX, proton induced Y-ray emission) and surface (XPS)analytical techniques revealed that the outer layer of the mordenite crystallites is enriched in silicon with respect to their core. This inhomogeneous Si-Al distribution and the formation of the coexisting phases is discussed in terms of a partial dissolution of the Si-rich Pyrex walls of the autoclave, after a long heating in alkaline medium.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
