Effect of Molecular Structure on the CO2 Separation Properties of Hydrophobic Solvents Consisting of Grafted Poly Ethylene Glycol and Poly Dimethylsiloxane Units

This work describes the preparation of a set of nine new novel hydrophobic PEG-substituted solvents. These solvents include linear, T-shaped, and disubstituted conformations of the PEG grafted with PDMS molecule. The effect of changing both the molecular conformation and length of PEG side arm on the physical properties and CO2 absorption capacity was studied. These solvents are intended for separation of CO2 and H2 in precombustion CO2 capture and are intended to replace the current-state-of-the-art glycol-based solvents and operate at a higher temperature. The properties of the disubstituted solvents are exceptionally well suited for precombustion CO2 capture applications because of their hydrophobicity, high CO2 solubility, low evaporation rate, and lack of foaming.