The AEROPILs Generation: Novel Poly(Ionic Liquid)-Based Aerogels for CO2 Capture

Abstract

CO₂ levels in the atmosphere are increasing exponentially. The current climate change effects motivate an urgent need for new and sustainable materials to capture CO₂. Porous materials are particularly interesting for processes that take place near atmospheric pressure. However, materials design should not only consider the morphology, but also the chemical identity of the CO₂ sorbent to enhance the affinity towards CO₂. Poly(ionic liquid)s (PILs) can enhance CO₂ sorption capacity, but tailoring the porosity is still a challenge. Aerogel's properties grant production strategies that ensure a porosity control. In this work, we joined both worlds, PILs and aerogels, to produce a sustainable CO₂ sorbent. PIL-chitosan aerogels (<i>AEROPILs</i>) in the form of beads were successfully obtained with high porosity (94.6-97.0%) and surface areas (270-744 m²/g). <i>AEROPILs</i> were applied for the first time as CO₂ sorbents. The combination of PILs with chitosan aerogels generally increased the CO₂ sorption capability of these materials, being the maximum CO₂ capture capacity obtained (0.70 mmol g^-1, at 25 °C and 1 bar) for the CHT:P[DADMA]Cl_30%<i>AEROPIL</i>.