The formation of superparamagnetic zeolite hybrid materials through a multistep process

Smith, Daniel Peter (2022). The formation of superparamagnetic zeolite hybrid materials through a multistep process. University of Birmingham. Ph.D.

Smith2022PhD.pdf
Text - Accepted Version
Restricted to Repository staff only until 31 December 2024.
Available under License All rights reserved.
Download (7MB) | Request a copy

Abstract

The development of superparamagnetic hybrid zeolites would allow for easier solid-liquid separations by magnetic methods to use, for example, in the remediation of nuclear waste. The aim of this thesis is to develop and test an optimised route to achieve this.

The work presented starts by building upon the literature to develop and optimise the aqueous ion exchange of transition metals (Fe2+, Co2+, Ni2+, Mn2+, Zn2+) in zeolites A, X and Y using just one step. Then a method of developing magnetic particles which are encapsulated within a vitreous aluminosilicate matrix made from the exchanged zeolites has been developed. The method has been optimised for zeolites A, X and Y using different transition metals. These materials recorded magnetic moments of up to 65.78, 55.95 and 50.05 emu/g of magnetic material for zeolites A, X and Y respectively. The use of a digestion or milling prior to the zeolite synthesis provided the means to reduce particle size and overcome differences in solubility to facilitate nucleation. Finally, several novel synthesis methods for creating a superparamagnetic form of zeolites A, X, Y and chabazite using the vitreous matrix have been developed with magnetic moments of 12.2 emu/g recorded. The final, magnetised zeolites are shown to ion exchange with no reduction in measured capacity.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):