Home
Resources
Publications
Thermal Collapse and Hierarchy of Polymorphs in a Faujasite-Type Zeolite and Its Analogous Melt-Quenched Glass

Thermal Collapse and Hierarchy of Polymorphs in a Faujasite-Type Zeolite and Its Analogous Melt-Quenched Glass

Theresia Palenta, Sindy Fuhrmann, G Neville Greaves, Wilhelm Schwieger, Lothar Wondraczek

J Chem Phys. 2015 Feb 28;142(8):084503.

PMID: 25725741

Abstract:

We examine the route of structural collapse and re-crystallization of faujasite-type (Na,K)-LSX zeolite. As the first step, a rather stable amorphous high density phase HDAcollapse is generated through an order-disorder transition from the original zeolite via a low density phase LDAcollapse, at around 790 °C. We find that the overall amorphization is driven by an increase in the bond angle distribution within T-O-T and a change in ring statistics to 6-membered TO4 (T = Si(4+), Al(3+)) rings at the expense of 4-membered rings. The HDAamorph transforms into crystalline nepheline, though, through an intermediate metastable carnegieite phase. In comparison, the melt-derived glass of similar composition, HDAMQ, crystallizes directly into the nepheline phase without the occurrence of intermediate carnegieite. This is attributed to the higher structural order of the faujasite-derived HDAcollapse which prefers the re-crystallization into the highly symmetric carnegieite phase before transformation into nepheline with lower symmetry.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AS21241	Faujasite Type Zeolite			Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: