Changes in the medium-range order of zeolite A by mechanical and thermal amorphization

Crystalline zeolite A was amorphized by mechanical and thermal treatments, and the resulting changes in the atomic arrangement are characterized by HEXRD, 27Al MAS NMR and Raman spectroscopy. HEXRD measurements revealed that the 6R and 8R rings are distorted and/or destroyed, while the 4R ring is preserved during mechanical treatment, but all rings are distorted and/or destroyed by thermal treatment. Data from 27Al MAS NMR and Raman spectroscopy also support these results. Furthermore, recrystallization behavior is found to be different between mechanically and thermally amorphized solids.