SELECTIVE CO2 CAPTURE AND PHOTO-SWITCH IN NANOPOROUS MATERIALS

The potentials of nanoporous materials for gas capture, separation and catalysis is emerging as an important research area for energy and environment issues. Our contribution was directed to the design and synthesis of customized materials for selective CO2 sequestration. MOFs and nanoporous polymers endowed with dynamic and responsive to chemical and photo-irradiation stimuli were prepared. In particular, a novel MOF family built by bipyridine-based pillars and layers of cycloaliphatic ligands were organized in stable interpenetrated architectures. Thy showed accessible galleries for favourable CO2 diffusion with well-defined pressure gates, useful for most effective deliverable-gas cycles. The steric and electronic properties of the pores was drove a virtually total selectivity towards nitrogen, as shown by competitive breakthrough runs under typical industrial fume release gas-mixture composition (15/85 N2/CO2). In turn, gas sorption influences the dynamic properties of the framework. The intriguing dynamic modulation was addressed by gas anisotropy and relaxation-time solid-state NMR measurements. Moreover, the integration of photo-active moieties in the very frame of polymeric porous frameworks (POPs or POPs) allowed for the construction of covalent contractile mano-sponges. The photo-switch as a monomeric unit exhibited a 100% conversion in the solid state, unlike photo-switch in solution. Structure expansion-contraction cycles corresponded to CO2 adsorption-desorption phenomenon.