Temperature and CO2 responsive polyethylenimine for highly efficient carbon dioxide releaseElectronic supplementary information (ESI) available: 1H and 13C NMR spectrometry of the acylation reaction, the reactor setup together with a absorption and desorption measurement. See DOI: 10.1039/c4ra13710h

Post combustion carbon dioxide capture with aqueous polymer solutions is a field of major interest. Via acylation of commercially available polyethylenimine ( b -PEI) with butyric anhydride, lower critical solution temperature (LCST) behaviour together with a reversible pH shift was found in water as well as in CO 2 containing aqueous solutions. As expected, a low CO 2 absorption capability of the acylated thermosensitive b -PEI was measured in a stirred tank reactor. However, the observed improved CO 2 release in the desorption process associated with the LCST behaviour of the polymer is a "green" tool to face high efficiency loss in standard CO 2 capturing processes. Temperature and CO 2 responsive behaviour and highly efficient carbon dioxide release was achieved via acylation of commercial available polyethylenimine.