CHARACTERIZATION OF IONIC LIQUIDS AND THEIR MIXTURES WITH CO-SOLVENTS BY DYNAMIC LIGHT SCATTERING (DLS)
The paper focuses on the determination of thermophysical properties of ionic liquids and their mixtures with co-solvents by dynamic light scattering. The presentation of the methodological principles of dynamic light scattering and its experimental realization includes light scattering from the bulk of fluids and the application of the method to fluid surfaces, also called surface light scattering. Specific examples are given for a variety of thermophysical properties accessible both by dynamic light scattering from the bulk of fluids and by surface light scattering, i.e., thermal and/or mutual diffusivity, dynamic viscosity, speed of sound, sound attenuation and dynamic or kinematic viscosity, surface tension, and interfacial tension. Besides offering a significant contribution to a reliable database, the determination of macroscopic thermophysical properties by dynamic light scattering provides also a close insight into the bulk structure and the fluid structure at the phase boundary of ionic liquid co-solvent mixtures. The simultaneous determination of viscosity and surface tension suggests that no co-solvent is present at the phase boundary if its concentration is below a certain threshold, depending on the strength of Coulomb interactions. Furthermore, the results indicate a possible formation of hydrogen-bonded complexes in ionic liquid co-solvent mixtures. By the combination of viscosity and diffusion measurements via the Stokes-Einstein relation the correlation length of the concentration fluctuations is accessible. The latter indicates that water is linked in a special state to the ions in mixtures with ionic liquids.
Andreas Paul Fr(a)ba Alfred Leipertz
Erlangen Graduate School in Advanced Optical Technologies (SAOT), University of Erlangen-Nuremberg,P Institute of Engineering Thermodynamics (LTT), University of Erlangen-Nuremberg,Am Weichselgarten 8,
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
1253-1268
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）