Amine-functionalized poly(ionic liquid) brushes for carbon dioxide adsorption

Amine-functionalized imidazolium-based poly(ionic liquid) brushes on titanate nanotubes are synthesized using a convenient “grafting through” technique. The carbon dioxide adsorption performance of the synthesized polymer brushes is evaluated using temperature programmed desorption (TPD) process. TPD profiles of the synthesized polymer brushes after carbon dioxide adsorption reveal that carbon dioxide molecules can adsorb on the synthesized polymer brushes through physical adsorption, reaction with 2-position carbon of imidazole rings, and chemical reaction with amine groups. The total carbon dioxide adsorption capacity of the synthesized poly(ionic liquid) brushes with polymer content of 46 wt.% achieves 2.43 mmol g−1 at 25 °C under carbon dioxide partial pressure of 0.2 bar, higher than that of the corresponding free polymer powders (1.28 mmol g−1) under the same conditions. The total adsorption capacity decreases to 1.46 mmol g−1 after two TPD adsorption/desorption cycles and it however remains almost constant in the later cycles.