Reversible Reaction Of CO2 Research Articles

Novel aminated F-Ce nanosheet mixed matrix membranes with controllable channels for CO2 capture

Membrane separation is a novel technology that has been widely studied for efficient CO2 capture. This study aims to synthesize novel porous amino-functionalized nanosheets using PEI (polyethyleneimine) (PEI-F-Ce) and PEI-F-Ce/polyethylene oxide (PEO) mixed matrix membranes (MMMs). PEI-F-Ce nanosheets were prepared via the electrostatic self-assembly method, allowing for the adjustment of both lateral and pore sizes of the nanosheets by varying the PEI concentration. The MMMs loaded with 2 % PEI-F-Ce-2.5 nanosheets exhibit excellent CO2 permeability (641 Barrer) and outstanding CO2/N2 selectivity (70.1). These values surpassed those of pure PEO membranes by 62 % and 53 %, respectively, exceeding the 2019 upper bound. PEI-F-Ce-2.5 nanosheets with a stable pore channel 3.406 nm improved CO2 transport and showed a large CO2 adsorption capacity of 1.32 mmol g−1, leading to enhanced the CO2/N2 reaction selectivity. Moreover, the reversible reaction of CO2 with –NH2 enhanced the CO2/N2 selectivity by 5.1 times at −20 °C, thereby highlighting its potential for cryogenic gas separation applications.

Preparation of Polyurethane‐Urea Elastomers Using Low Molecular Weight Aliphatic Diamines Enabled by Reversible CO2 Chemistry

AbstractThe use of low molecular weight (LMw) aliphatic diamines for the synthesis of polyurethane‐urea elastomers (PUUEs) is an effective method for introducing abundant, strong hydrogen bonds with the aim of improving the thermal and mechanical properties of PUUEs. However, the reaction between isocyanates and LMw aliphatic diamines is too rapid to produce PUUEs. In this study, PUUEs incorporating LMw aliphatic diamines as chain extenders are prepared via the reversible reaction of CO2 with diamines. The phase separation, thermal properties, and thermomechanical and mechanical properties of polyurethane materials are investigated as the chain extender changed from diol to diamine. Replacing the diol chain extenders with diamine results in the formation of more abundant and stronger hydrogen bonds in PUUEs, which enables the assembly of long range ordered structures and improved microphase separation. The tensile strengths of PUUEs, from 8.4 to 13 MPa, are much higher than their corresponding polyurethanes, owing to the physical crosslinks formed by the more and stronger hydrogen bonds in the PUUEs.

Carbon dioxide promoted reductive amination of aldehydes in water mediated by iron powder and catalytic palladium on activated carbon

A mixture of iron powder and catalytic palladium on activated carbon has been developed for reductive amination of various aromatic aldehydes, including 2-pyridinecarboxaldehyde, in water under CO2 atmosphere. The reversible reaction of CO2 with water could form carbonic acid and hydrogen transfer from water to Pd(0) took place with the presence of iron powder, leading to formation of high-active Pd hydrides for the reductive amination process. On the other hand, the reaction system could be inherently neutralized by ready removal of CO2, thus resulting in facile post-processing.

Sustainable Chemistry: Reversible reaction of CO2 with amines

The reaction of primary and secondary amines with CO2 has been successfully leveraged to develop sustainable processes. In this article, we review specific examples that use the reversible reaction of CO2 with amines to synergistically enhance reaction and recovery of the products. The three cases of interest highlighted herein are: (i) reversible protection of amines, (ii) reversible ionic liquids for CO2 capture and chemical transformations, and (iii) reversible gels of ethylene diamine. These examples demonstrate that the reversible reaction of amines with CO2 is one of the tools in the sustainable technology’s toolbox.

Reversible Covalent Chemistry of CO2.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reversible covalent chemistry of CO2.

Reversible reaction of CO2 with fluorescently active amines in polar aprotic solvent rapidly results in carbamic acids, which significantly enhances the solution fluorescence.