Polyethyleneimine (PEI) is a synthetic, water-soluble, linear or branched polyamine, cationic organic polymer for carbon dioxide capture, electronic and biomedical applications. PEI modified mesoporous adsorbents can be used to adsorb carbon dioxide. It is considered a typical carrier material and is widely used in gene delivery systems for its ability to build complexes with DNA and support the release of endosomes through the "proton sponge effect".
