Excess properties, intermolecular structure, and CO2 absorption performance of n-propanol/isopropanol and 3-diethylaminopropylamine binary mixed system

Abstract

In this work, the density (ρ) and viscosity (η) values were measured experimentally for the n-propanol (NPA) /isopropanol (IPA) (1) + 3-diethylaminopropylamine (DEAPA) Abd et al. (2020) (2) binary mixed system at T = 298.15–318.15 K and P = 100.5 kPa. To further study the physical and chemical properties of the binary mixed system, their excess molar volume (V_m^E), viscosity deviation (Δη), and excess Gibbs free energy (ΔG^⁎E) were calculated, through which there is an interaction between 3-diethylaminopropylamine and n-propanol/isopropanol molecules. To validate the reliability of the basic data, several semi-empirical models were used to predict the experimental densities and viscosities, among which the Jouyban - Acree model (J-A) and the nonlinear least squares method for fitting the density data of the binary mixed system to the composition and temperature, the McAllister four-body viscosity model was used to fit the viscosity data to the composition of binary mixed systems, and the calculated results of ΔG^⁎E, Δη and V_m^E were fitted using the Redlich-Kister (R - K) equations. In addition, the presence of intermolecular hydrogen bond (IHB) structure of the form as -OH···NH₂- in the system was demonstrated by spectroscopic characterizations including Raman, ultraviolet (UV) and nuclear magnetic resonance hydrogen spectroscopy (¹H NMR), and the existence of IHBs among the binary mixed system was further verified based on computational chemical theory. Finally, the CO₂ uptake studies were conducted to compare with the monoamine and alcohol-amine mixed solutions to provide a new way for CO₂ capture.