| Autor: |
Canongia Lopes JN; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , 2780-157, Oeiras, Portugal.; Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , Avenida Rovisco Pais, 1049-001 Lisboa, Portugal., Esperança JM; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , 2780-157, Oeiras, Portugal., de Ferro AM; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , 2780-157, Oeiras, Portugal., Pereiro AB; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , 2780-157, Oeiras, Portugal., Plechkova NV; The QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen's University of Belfast , Stranmillis Road, Belfast BT9 5AG, U.K., Rebelo LP; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , 2780-157, Oeiras, Portugal., Seddon KR; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , 2780-157, Oeiras, Portugal.; The QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen's University of Belfast , Stranmillis Road, Belfast BT9 5AG, U.K., Vázquez-Fernández I; The QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen's University of Belfast , Stranmillis Road, Belfast BT9 5AG, U.K. |
| Abstrakt: |
This study is centered on the thermophysical characterization of different families of alkylammonium nitrate ionic liquids and their binary mixtures, namely the determination at atmospheric pressure of densities, electric conductivities and viscosities in the 288.15 < T/K < 353.15 range. First, measurements focusing on ethylammonium, propylammonium and butylammonium nitrate systems, and their binary mixtures, were determined. These were followed by studies involving binary mixtures composed of ethylammonium nitrate (with three hydrogen bond donor groups) and different homologous ionic liquids with differing numbers of hydrogen bond donor groups: diethylammonium nitrate (two hydrogen bond donors), triethylammonium nitrate (one hydrogen bond donor) and tetraethylammonium nitrate (no hydrogen bond donors). Finally, the behavior of mixtures with different numbers of equivalent carbon atoms in the alkylammonium cations was analyzed. The results show a quasi-ideal behavior for all monoalkylammonium nitrate mixtures. In contrast, the other mixtures show deviations from ideality, namely when the difference in the number of carbon atoms present in the cations increases or the number of hydrogen bond donors present in the cation decreases. Overall, the results clearly show that, besides the length and distribution of alkyl chains present in a cation such as alkylammonium, there are other structural and interaction parameters that influence the thermophysical properties of both pure compounds and their mixtures. |
