Molecular Self-Diffusion Coefficients in Solutions of Dimethylsulfoxide in Monoethanolamine

The molecular self-diffusion coefficients of dimethylsulfoxide (DMSO) in monoethanolamine (MEA) are measured by means of proton NMR spin-echo spectroscopy at 304.6 K and DMSO concentrations varying from 0 to 30 mol %. The drop in the self-diffusion coefficient of MEA observed at low DMSO concentrations is attributed to the solvophobic effect DMSO molecules exhibit in solutions in MEA. The results obtained for the considered system are compared to similar data for the DMSO–ethylene glycol system. The differences between the two systems are explained by the higher lability of spatial hydrogen bond networks in liquid MEA, compared to ethylene glycol.