Spectroscopic study on the intermolecular interaction of SO_2 absorption in poly-ethylene glycol+H_2O systems

摘要

Poly-Ethylene Glycol (PEG) 300+H_2O solutions (PEGWs) has been used as a promising medium for the absorption of SO_2. We investigated the UV, FTIR, ~1H-NMR, and fluorescence spectra in the absorption processes of SO_2 in PEGWs to present an important absorption mechanism. Based on the spectral results, the possibility of intermolecular hydrogen bond formation by hydroxyl oxygen atom in the PEG molecule with hydrogen atom in H_2O and S…O interaction formation by the oxygen atoms in PEG with the sulfur atom in SO_2 are discussed. This shows that the spectral changes may be due to the formation of -CH_2CH_2O(H)…HOH…and -CH_2-CH_2-O(CH_2-CH_2-)…HOH… in PEGWs and the formation of -CH_2CH_2OH…OSO…, and intermolecular S…O interaction between PEG and SO_2 as the formation of -CH_2CH_2OCH_2CH_2O(H)…(O)S(O)… and -CH_2-CH_2-O(CH_2-CH_2-)…(O)S(O)…. The existence of these bonds benefits the absorption and desorption processes of SO_2 in PEGWs.