Presented here is the incorporation and attachment of polyethylenimine (PEI) to a mesoporous silica support. 

Polyethylenimine is reported to be one of the cheapest and most effective carbon dioxide (CO2) removal agents known. Functionalization to a solid support affords a readily utilized form of PEI for CO2 removal applications. 

While others have attempted to incorporate PEI into mesoporous silica, the surface chemistry (acidity) of the silica causes the PEI to clump, blocking the pores, and thus decreasing the CO2 adsorption. In this work, we first treat the surface with a monolayer of amine-silane to neutralize the acidity, then treat with PEI, affording the desired PEI coated mesoporous silica. 

The resulting material is capable of adsorbing 5-6% CO2 by weight. It is readily regenerated by heating in an inert atmosphere or under vacuum. Testing has shown the material to maintain its CO2 capacity over multiple adsorption/regeneration cycles.