Excess properties, spectral analysis and computational chemistry of (1,3-propanediol + ethylenediamine) ion-like liquids for CS2 capture

Abstract

Density and viscosity of (1,3-propanediol (1,3-PDO) (1) and ethylenediamine (EDA) (2)) ion-like liquids were measured at T = (293.15–318.15) K with the step of 5 K under atmospheric pressure. On the basis of basic density and viscosity, the activation thermodynamics and excess properties of the ion-like liquids, including the excess molar volume (VmE), partial molar volume (V¯), apparent molar volume (Vφ), thermal expansion coefficient (αP), viscosity deviation (Δη), activation enthalpy change (ΔH*), activation entropy change (ΔS*), activation Gibbs energy (ΔG*) and excess Gibbs energy of activation of viscous flow (ΔG*E), were systemically researched. Meanwhile, the Jouyban-Acree model and the nonlinear least-squares method were used to fit the density, the McAllister three-body equation, McAllister four-body equation and the Arrhenius equation were used to fit dynamic viscosity and viscosity, and the R-K equation was used to fit the excess molar volume, viscosity deviation and excess Gibbs energy of activation of viscous flow. After that, based on Fourier Transform infrared spectroscopy (FTIR), Raman spectral (Raman), ultraviolet spectral (UV), fluorescence spectral (FLS) and nuclear magnetic resonance spectroscopy (1H NMR) spectral results and density functional theory (DFT) calculation results, it is proved that there are hydrogen bonding of 1,3-PDO with EDA as the form of ···HOCH2CH2CH2OH···NH2CH2CH2N(H2)···. In addition, the existence of ion-like interaction and van der Waals effects in ion-like liquids was novelty found. This provides preliminary work preparation for exploring the absorption and fixation of CS2 in ion-like liquids.