Interlocking dendritic fibrous nanosilica into microgranules by polyethyleneimine assisted assembly: in-situ neutron scattering and CO₂ capture studies

Amine-based solid nano-adsorbents have shown tremendous potential for mitigating the CO₂ emissions from fossil fuel-based power plants. The conventional approaches for achieving nano-adsorbents utilize the loading of the amines in well-defined mesopores which face several challenges including, pore blocking, slow adsorption kinetics, and pressure drop in the temperature swing adsorption/desorption cycle. These challenges were resolved by using dendritic fibrous nano-silica (DFNS), with unique fibrous morphology consisting of both mesopores and macropores. However, the nanosized particles of DFNS did not allow efficient use of these sorbents for CO₂ capture with required stability and kinetics. In this work, we report the synthesis of DFNS microgranules using the one-step evaporation induced assembly of the nanometer-sized DFNS particles and polyethyleneimine (PEI), keeping textural properties of the DFNS intact