Physicochemical Characterization of Two Protic Hydroxyethylammonium Carboxylate Ionic Liquids in Water and Their Mixture

Author(s)

Augusto, Ferrari Felipe ; Francisco, Malaret ; Stephen, Eustace ; Jason, Hallett ; van der Wielen, Luuk ; Geert-Jan, Witkamp ; Bruno, Forte Marcus

• Document type: Journal article
• Source: JOURNAL OF CHEMICAL AND ENGINEERING DATA; v. 67, n. 6, p. 17-pg., 2022-06-09.

Abstract

A systematic study on the physicochemical properties of two and 2-hydroxyethylammonium hexanoate ([Mea][Hex])} and their mixtures with water was performed. The density and viscosity were assessed across the entire range of aqueous dilutions between 278 and 393 K. The conductivities, water activities, and surface tension of the binary systems in water were also assessed, and the influence of anions was evaluated. Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and 1H and 13C nuclear magnetic resonance (NMR) techniques were used to study the systems at different IL compositions. The excess molar volumes (VE) and thermal expansion coefficients were calculated, with negative values for VE across the entire concentration range. Density data were fitted to a polynomial for density prediction, function of temperature, and concentration, with the average deviation percentage not exceeding 0.63%. The viscosities of the binary systems were studied considering six different models and were better predicted by the model of Herra??ez et al. at IL concentrations higher than 0.25 mole fraction. The systems containing [Hex]- exhibited higher water activities and lower conductivity and surface tension. All studied systems exhibited a glass transition event, which varied according to the IL composition. The FTIR and NMR analysis confirmed the distinct molecular arrangement of [Mea][Ac] and [Mea][Hex] systems. (AU)

• FAPESP's process: 15/50612-8 - An integrated approach to explore a novel paradigm for biofuel production from lignocellulosic feedstocks
• Grantee: Telma Teixeira Franco
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/24520-4 - New generation biofuel and feedstock pre-treatment challenge: a novel strategy to assess biomass processing using mixtures of ionic liquids and ultrasound, a simultaneous and multivariate approach
• Grantee: Marcus Bruno Soares Forte
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 19/19976-4 - Lignocellulosic biomass processing using ionic liquids for biorefinery application
• Grantee: Felipe Augusto Ferrari
• Support Opportunities: Scholarships in Brazil - Doctorate