Electrical impedance spectroscopy characterisation of supported ionic liquid membranes |
| |
Authors: | Raquel Fortunato, Luí s C. Branco, Carlos A.M. Afonso, Juana Benavente,Jo o G. Crespo |
| |
Affiliation: | aREQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal bCentro de Química Física Molecular, Instituto Superior Técnico, 1049-001 Lisboa, Portugal cDepartamento de Física Aplicada, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain |
| |
Abstract: | Supported liquid membranes (SLMs), prepared by immobilising the room temperature ionic liquids (RTILs) [CnMIM]PF6 (n = 4 and 8) and [C10MIM]BF4 in a polyvinylidene (PVDF) supporting membrane, were prepared and characterised by electrochemical impedance spectroscopy (IS). This non-invasive technique allows the determination of the electrical properties of a given sample, such as the electrical resistance and capacitance under working conditions, i.e., in contact with saline solutions. Bearing in mind that the water content of the ionic liquids can drastically affect their physicochemical properties, impedance measurements of the SLMs, placed between two aqueous solutions, were carried out at regular time intervals, in order to assess the impact of the presence of water inside the RTILs on the electrical properties of supported ionic liquid membranes. The electrical resistance of the SLMs and its variation during long-term operation was also used as a physical parameter to identify the presence/loss of ionic liquid from the pores of the support. Additionally, the comparison of the IS results obtained for the SLMs with those obtained for the supporting membrane was carried out, in order to gather information about electrical changes associated with the presence of ionic liquid in the pores. |
| |
Keywords: | Ionic liquids Liquid membranes Impedance spectroscopy Ion-conducting membranes Membrane stability |
本文献已被 ScienceDirect 等数据库收录! |
|