Microwave-Assisted Hydrothermal Green Synthesis of Analcime Icositetrahedra: Insight into Intermediates Formed in the Reversed Crystal Growth Process

作者：Samadi Maybodi Abdolraouf^*; Pourali S Masoomeh

来源：European Journal of Inorganic Chemistry, 2014, 2014(7): 1204-1210.

DOI：10.1002/ejic.201301381

• Zeolites
• Analcime
• Microwave chemistry
• Reversed crystal growth
• Template synthesis

This contribution reports new details that we have observed in the early stages of the reversed crystal growth of zeolite analcime icositetrahedra synthesized by a facile microwave-assisted hydrothermal method in the presence of sodium carboxymethyl cellulose (CMC) as a green template. The detailed time-dependent evolution of the crystallization and the morphology of the crystals were elucidated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analysis. Under microwave irradiation and in the viscous environment provided by CMC, some kinetically controlled stages provided new information about the early stages of analcime crystal growth; hollow microsphere thin-shell nanoplatelets and nanorods orderly fill the core, and this creates a thick core. The influence of parameters such as CMC concentration, microwave irradiation time, and hydrothermal reaction time on the crystallinity, size, and morphology of the analcime crystals was thoroughly investigated. Perfect large analcime icositetrahedra were obtained only at CMC concentrations and long microwave irradiation times. Moreover, the employment of acid-treated seeds led to the formation of analcime nanocrystals of 60 +/- 20 nm accompanied by the retained ANA parent. Our results suggest that these newly revealed orientations of the precursors could shed light on the early stages of reversed crystal growth of other zeolites and microstructured materials in the field of materials science and crystal engineering.

• 出版日期2014-3