Physical Sciences and Mathematics Commons^™

Investigations Of The Crystallization Processes Of Molecular Sieves, Lu Zhang

Electronic Thesis and Dissertation Repository

Molecular sieves have been used extensively in industrial fields. A better understanding of their crystallization processes is very useful for controlling the structural properties in order to meet the industrial needs. This thesis focuses on examining the crystallization of several catalytically important molecular sieves by dry gel conversion (DGC) method which includes steam-assisted conversion (SAC) and vapor-phase transport (VPT), or hydrothermal synthesis (HTS) method or a combination of both.

For SAPO-34 templated by DEA, it crystallizes similarly under SAC and VPT conditions. It forms from the transformation of a semi-crystalline layered phase. When morpholine was used as the template, the …

Hydrothermal Chemistry, Crystal Structures, And Spectroscopy Of Novel Fluorides And Borates, Christopher Underwood

All Dissertations

This dissertation is a two-part manuscript highlighting the utilities of the hydrothermal method for exploring phase space, then extending that to the targeted growth of potentially useful materials. Chapters 3 - 5 discuss the synthesis of Group 4 fluorides and oxyfluorides. The study of this class of compounds in regards to their single crystal structures is a rich, but neglected area. Among the Group 4 metals, compounds based on Zr and Ti have been extensively studied, while those based on Th and Hf are sparsely reported and those based on Ce(IV) are nearly completely neglected. Using the hydrothermal method, many …