Effect of polyether amine canopy structure on carbon dioxide uptake of solvent-free nanofluids based on multiwalled carbon nanotubes

A series of specific solvent-free nanofluids with ionically tethered polyether amine terminated polymers were successfully prepared and evaluated based on multiwalled carbon nanotubes (MWCNTs). The newly synthesized sorbents exhibited enhanced carbon dioxide (CO₂) capture capacities compared to their corresponding polyether amine and pristine MWCNTs. The effects of polyether amine canopy structure such as amine types, Molecular weight (Mw), Ethylene Oxide/Propylene Oxide (EO/PO), viscosity and melting point on CO₂ capture capacities were investigated. It had been demonstrated that the sorbents impregnated with more unprotonated amine groups and higher Mw or EO/PO showed larger CO₂ capture capacities and good stabilities over multiple adsorption-desorption cycles. Last but not least, we also demonstrated that the lower melting point and viscosity were beneficial for the CO₂ uptake.