Combined Surface Light Scattering and Pendant-Drop Experiments for the Determination of Viscosity and Surface Tension of High-Viscosity Fluids Demonstrated for Ionic Liquids

Zhai Z, Jander JH, Bergen A, Cui J, Meyer K, Koller TM (2022)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2022

Journal

International Journal of Thermophysics Springer Verlag (Germany)

Book Volume: 43

Article Number: 178

Journal Issue: 12

DOI: 10.1007/s10765-022-03103-z

Abstract

The present study provides a strategy for the determination of the viscosity and surface tension of high-viscosity fluids in the form of ionic liquids (ILs) at equilibrium conditions by combining surface light scattering (SLS) and the pendant-drop (PD) method within one experimental setup. Through the study of the same sample under identical conditions by both methods inside a closed system, the surface tension determined via the PD method can be directly used to evaluate the dynamics of surface fluctuations of ILs with an overdamped behavior probed by SLS for accessing their viscosity. In connection with the SLS experiments, variations in the applied detection geometries in reflection and transmission direction and in the probed wave vectors down to relatively small values were also addressed. The reliability and self-consistency of SLS and the PD method applied within the same sample cell has been proven by investigating the reference fluids tris(2-ethylhexyl) trimellitate (TOTM) and n-dodecane featuring relatively high and low viscosities. For the two studied model ILs of opaque to non-transparent color, i.e., the hydrophobic 1-methyl-3-octylimidazolium hexafluorophosphate ([OMIM][PF6]) and the hydrophilic 1,3-bis(2-(2-methoxyethoxy)ethyl)imidazolium iodide ([(mPEG2)2Im]I), the combination of PD measurements and SLS experiments in reflection direction performed at ambient pressure between (303 and 373) K allowed access to the viscosity and surface tension with typical relative expanded uncertainties of (4 and 2) %. These results agree well with own viscosity data from capillary viscometry and experimental data in the literature, demonstrating the performance of the novel approach for the contactless in-situ measurement of viscosity and surface tension of fluids with relatively high-viscosity such as ILs.

Authors with CRIS profile

Ziwen Zhai Collaborative Research Centre 1452/1 Catalysis at Liquid Interfaces (CLINT) Julius Jander Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Alexander Bergen Collaborative Research Centre 1452/1 Catalysis at Liquid Interfaces (CLINT) Junwei Cui Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Karsten Meyer Lehrstuhl für Anorganische und Allgemeine Chemie Thomas Manfred Koller Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP)

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies

Related research project(s)

Properties of the gas/liquid interface of Interface-enhanced SILP systems (B04) (SFB 1452 CLINT B04) Catalysis at Liquid Interfaces (CLINT) (SFB 1452 CLINT) Jan. 1, 2021 - Dec. 31, 2024

How to cite

APA:

Zhai, Z., Jander, J.H., Bergen, A., Cui, J., Meyer, K., & Koller, T.M. (2022). Combined Surface Light Scattering and Pendant-Drop Experiments for the Determination of Viscosity and Surface Tension of High-Viscosity Fluids Demonstrated for Ionic Liquids. International Journal of Thermophysics, 43(12). https://dx.doi.org/10.1007/s10765-022-03103-z

MLA:

Zhai, Ziwen, et al. "Combined Surface Light Scattering and Pendant-Drop Experiments for the Determination of Viscosity and Surface Tension of High-Viscosity Fluids Demonstrated for Ionic Liquids." International Journal of Thermophysics 43.12 (2022).

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