Towards Designing Composite membranes for CO2 Separation: The Inclusion of Hybrid TiO2-PEG Structures and the Study of their Interfaces

Abstract

This thesis work aims towards designing hybrid membranes for CO2 separation in the post-combustion process. The different methods of existing technologies are compared and assessed for their merit, and the decision of using inorganic titanium dioxide supports integrated with a grown polymeric/PEG layer is made. First, the structure of the interfacing group is determined and narrowed down to phosphonic-based or silane-based anchoring groups. The modification of various titanium oxide surfaces (i.e. particle, flat and porous) is performed with each group, and particles were found to yield the highest surface modification. Secondly, the functionalized particles of titania were then studied for their potential with si-ATRP and si-ROMP. In the case of phosphonic acid functionalized titania, the particles yielded a bromine terminus that could be used for si-ATRP. In the case of the silane grafted titania particles, further functionalization was required to ultimately yield a norbornenyl group that can be used for si-ROMP. Both techniques were shown to work, and were thus applied to longer ceramic tubes. Finally, the development of two pathways (“Coating Onto” and “Grafting From”) were assessed for their ability to modify the tubular ceramic support and preliminary gas separation tests were performed.