J Solution Chem (2010) 39: 1531–1548 DOI 10.1007/s10953-010-9600-3 Volumetric Properties of Ethylammonium Nitrate + γ -Butyrolactone Binary Systems: Solvation Phenomena from Density and Raman Spectroscopy Ramzi Zarrougui · Mahmoud Dhahbi · Daniel Lemordant Received: 28 February 2010 / Accepted: 19 May 2010 / Published online: 13 October 2010 © Springer Science+Business Media, LLC 2010 Abstract The densities of binary mixtures of ethylammonium nitrate (EAN) ionic liquid (IL) and γ -butyrolactone (BL) have been measured over the entire range of concentrations at 293.15, 298.15, 303.15, 308.15, 313.15 and 318.15 K and under ambient pressure. Ex- perimental densities were used to calculate excess molar volumes V E m , isobaric and excess isobaric expansion coefficients α and α E . The excess molar volumes have both negative and positive values, while the excess isobaric expansion coefficients are negative over the en- tire composition range. The V E m values have been fitted to the Redlich-Kister polynomial equation, and other volumetric properties such as the partial molar volumes V mi , the excess partial molar volume V E mi and the partial molar volumes at infinite dilution V ∞ mi were cal- culated. The results have been interpreted in terms of dipole-dipole interactions, hydrogen bonds formation and structural factors of these mixtures. The FT-Raman spectroscopy study of the intensity variations of some characteristic bands such as the C=O stretching band at 1763 cm −1 , C–O symmetric stretching band at 932 cm −1 and C–C stretching band at 872 cm −1 of BL has been undertaken. The solvation phenomenon is evidenced by the mod- ifications of these band intensities due to the presence of the IL ions. Moreover, the Raman spectroscopy corroborates the volumetric study. The average number of BL molecules in the primary solvation shell of the ethylammonium cation lies between 3 and 4 depending on the temperature. Keywords Ionic liquids · γ -Butyrolactone · Excess molar volume · Partial molar volume · Partial molar volume at infinite dilution · Raman spectroscopy R. Zarrougui ( ) · M. Dhahbi Laboratoire Eau et Technologies Membranaires, CERTE, B.P. 273, 8020 Soliman, Tunisia e-mail: ramzi.zarrougui@gmail.com D. Lemordant Laboratoire Physicochimie des Matériaux et des Biomolécules (PCMB, EA4244), Equipe CIME, Faculté des Sciences et Techniques, Université F. Rabelais, Parc de Grandmont, 37200 Tours, France