Activation Effect of Fullerene C 60 on the Carbon Dioxide Absorption Performance of Amine‐Rich Polypropylenimine Dendrimers

Converting amine‐rich compounds into highly effective carbon dioxide (CO 2 ) sorbents requires a better understanding and control of their properties. The reaction of fullerene C 60 with polyethyleneimine converts the polymer into a high‐performance CO 2 sorbent. In this study, experimental evidence is reported for the activation effect of C 60 on the amine moieties of the polymer. To do so, polypropylenimine (PPI) dendrimers that allowed for a systematic comparison of molecular composition and CO 2 absorption were used. The addition of C 60 to PPI to form PPI–C 60 results in a reduction of the energy barrier of CO 2 absorption, but also in a parallel decrease in the frequency of successful collisions between CO 2 and PPI–C 60 due to a possible disruption of the hydrogen‐bonding network of amino groups and bound water in PPI. This finding supports the existence of a non‐affinity “repulsive” effect between hydrophobic C 60 and hydrophilic amines that forces them to be actively exposed to CO 2 .