Synthesis and Characterization of Novel Facilitated Transport Membranes for CO2 Separation

As a response to the growing concern linked to the anthropogenic contribution to global climate change due to carbon emission, a large amount of research is now focused to develop new technologies for its capture prior to the release in the atmosphere. Amongst the various methodologies, gas separation membranes occupy an ever-growing share of the separation technologies. In particular, facilitated transport membranes (FTMs) are gaining an exponentially large interest in the research community. These films rely on a reversible reaction between a target component in the gas feed and functionalized groups embedded in the membrane matrix. Throughout this work different kinds of FTMs have been synthesized and tested, in order to gain insight on their permeation properties. A first part of the work was dedicated to the study of Polyvinyl alcohol based membrane, which were functionalized in two different ways: by the grafting of amine functionalized molecule to the polymeric chain and by the addition of nanoparticles provided with amine moieties. Subsequently, the main study presented in this thesis concerned the synthesis of selective films, resulted by the blending of polyvinylamine (for the functionality) and nanocellulose (for the structural support). Various ratios of the two components where explored at different degrees of humidity and good results were achieved, maxing the CO2/N2 selectivity at 211 the CO2/CH4 one at 122 at 35 °C. When swelling at high humidity was observed, several polymer modification were employed to tackle the issue, ranging from chemical cross-linking, thermal treatment and polymer purification. This allowed to increase the CO2/CH4 selectivity up to 410 at 35 °C and minimize swelling. Overall, it was possible to synthesize performing amine based fixed site facilitated transport membranes for the separation of carbon dioxide and find new methods for the improvements of their characteristics.