Reaction of Amino-Terminated PAMAM Dendrimers with Carbon Dioxide in Aqueous and Methanol Solutions.

Beijun Cheng,Angel E Kaifer

doi:10.3390/molecules27020540

Abstract

Polyamines have been used as active materials to capture carbon dioxide gas based on its well-known reaction with amines to form carbamates. This work investigates the reactions between three amino-terminated poly(amidoamine) (PAMAM) dendrimers (G1, G3 and G5) and CO2(g) in aqueous (D2O) and methanolic (CD3OD) solutions. The reactions were monitored using 1H NMR spectroscopy, and yielded dendrimers with a combination of terminal carbamate and terminal ammonium groups. In aqueous media the reaction was complicated by the generation of soluble carbonate and bicarbonate ions. The reaction was cleaner in CD3OD, where the larger G5 dendrimer solution formed a gel upon exposure to CO2(g). All reactions were reversible, and the trapped CO2 could be released by treatment with N2(g) and mild heating. These results highlight the importance of the polyamine dendrimer size in terms of driving changes to the solution’s physical properties (viscosity, gel formation) generated by exposure to CO2(g).

Highlights

Carbon dioxide reacts with amines to form carbamic acid [1]
This r tion has been used in supramolecular systems and is potentially useful to rem used in supramolecular systems [2,3] and is potentially useful to remove carbon dioxide gas from dioxide industrialgas emissions and, perhaps, for CO2 absorption as an atmospheric carbon carbon from industrial emissions and, perhaps, for CO 2 absorption as an capture and storage (CCS)
We conclude that the reaction of CO2 (g) with amine-terminated PAMAM

Summary

Introduction

Carbon dioxide reacts with amines to form carbamic acid [1]. This r tion has been used in supramolecular systems [2,3]. Is potentially useful to rem used in supramolecular systems [2,3] and is potentially useful to remove carbon dioxide gas from dioxide industrialgas emissions and, perhaps, for CO2 absorption as an atmospheric carbon carbon from industrial emissions and, perhaps, for CO 2 absorption as an capture and storage (CCS) method [4]. Mospheric carbon capture and storage (CCS) method [4].

Methods

Discussion

Conclusion