Static and dynamic dielectric properties of aminoalcohols in their pure liquid state and in mixtures with dioxane

What is behind a gas stream scrubbing liquid? Monoethanolamine/water mixtures as seen by dielectric relaxation spectroscopy

“…We provide reliable DR spectroscopy data covering, to the best of our knowledge, the broadest frequency and concentration range ever studied for this system near room temperature. The present DR data match previously studied limiting cases for 298.15 K, namely, dilute aqueous solutions 23 and neat aminoethanol, 21 and extend the available data base to moderate and high MEA content, including aqueous MEA with 30 mass% of amine, the solution generally considered as the reference absorbent of sour gases. Due to the high sensitivity of the used technique to solute-solute, solute-solvent and solvent-solvent interactions, we obtained unprecedented information on hydration and self-aggregation of MEA in water over the entire miscibility range.…”

“…According to IR spectroscopic data, 18 neat liquid a H-bonded network via intermolecular OHÁ Á ÁN Hbonds is formed, whereas in aqueous solutions, MEA molecules were found to integrate into the H-bonded network of water until at least MEA mole fractions of 0.08. As a result of this extended intermolecular hydrogen bonding, the overall rotational dynamics [20][21][22][23] and diffusion 24 are substantially retarded in liquid MEA [20][21][22]24 and its mixtures with water. 23,24 Evaluation of dielectric relaxation (DR) data obtained by Hornhardt and co-workers 21 for neat MEA and its solutions in dioxane even provided separate relaxation processes for individual MEA molecules and those involved in aggregates.…”

The Global Polarity of Alcoholic Solvents and Water – Importance of the Collectively Acting Factors Density, Refractive Index and Hydrogen Bonding Forces

“…The high average binding energy of the hydrogen bonds is compensated by the entropy gain resulting from the bending and breaking of the hydrogen bonds. This process is different for each monohydric and polyhydric alcohol, as dielectric spectroscopy shows [87–90] . Therefore, one can assume that a certain hydrogen bond density distribution is present and differs for monohydric and polyhydric alcohols.…”

“…This process is different for each monohydric and polyhydric alcohol, as dielectric spectroscopy shows. [ 87 , 88 , 89 , 90 ] Therefore, one can assume that a certain hydrogen bond density distribution is present and differs for monohydric and polyhydric alcohols.…”

9 Dielectric relaxation in solutions

“…187 Excess absorption at high frequencies was also observed for tetraethyleneglycol 188 and for aminoalcohols, which behave in a very similar way to polyols. 189 The competitive effects of self and hetero-association mixtures of mono and dihydric alcohols, eventually diluted in a non-polar solvent, were examined by the groups of Hanna 190 and Stockhausen. 191 Recently, Havriliak and Havriliak argued that the highfrequency wing of glycerol is an artefact arising from the inappropriate representation of the data by plots of eA(n) and eB(n) versus frequency or by Argand diagrams, eB = f(eA), which disappears when the complex polarizabilities, â(n) = (ê 2 1)/(ê + 2), are plotted.…”