Diffusivities of Ternary Mixtures of n-Alkanes with Dissolved Gases by Dynamic Light Scattering

Heller A, Giraudet C, Makrodimitri ZA, Fleys MSH, Chen J, van der Laan GP, Economou IG, Rausch MH, Fröba AP (2016)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2016

Journal

Journal of Physical Chemistry B American Chemical Society

Publisher: AMER CHEMICAL SOC

Book Volume: 120

Pages Range: 10808-10823

Journal Issue: 41

DOI: 10.1021/acs.jpcb.6b08117

Abstract

Theoretical approaches suggest that dynamic light scattering (DLS) signals from low-molecular-weight ternary mixtures are governed by fluctuations in temperature as well as two individual contributions from fluctuations in concentration that are related to the eigenvalues of the Fick diffusion matrix. Until now, this could not be proven experimentally in a conclusive way. In the present study, a detailed analysis of DLS signals in ternary mixtures consisting of n-dodecane (n-C12H26) and n-octacosane (n-C28H58) with dissolved hydrogen (H-2), carbon monoxide (CO), or water (H2O) as well as of n-C12H26 or n-C28H58 with dissolved H-2 and CO is given for temperatures up to 523 K and pressures up to 4.1 MPa. Thermal diffusivities of pure n-C12H26 and n-C28H58 as well as thermal and mutual diffusivities of their binary mixtures being the basis for the ternary mixtures with dissolved gas were studied for comparison purposes. For the investigated ternary mixtures, three individual signals could be distinguished in the time-resolved analysis of scattered light intensity by using photon correlation spectroscopy (PCS). For the first time, it could be evidenced that these signals are clearly associated with hydrodynamic modes. In most cases, the fastest mode observable for ternary mixtures is associated with the thermal diffusivity. The two further modes obviously related to the molecular mass transport are observable on different time scales and comparable to the modes associated with the concentration fluctuations in the respective binary mixtures. Comparison of the experimental data with results from molecular dynamics simulations revealed very good agreement.

Authors with CRIS profile

Andreas Heller Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Cédric Giraudet Erlangen Graduate School in Advanced Optical Technologies (SAOT) Michael Rausch Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Andreas Paul Fröba Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP)

Related research project(s)

Investigation of the diffusion coefficient of hydrogen, carbon monoxide, and water in n-alkanes by dynamic light scattering / Experimental investigation of surface tension and viscosity of representative wax samples at reaction conditions Nov. 9, 2015 - Dec. 31, 2017

Involved external institutions

National Centre for Scientific Research (NCSR) "Demokritos" GR Greece (GR)

How to cite

APA:

Heller, A., Giraudet, C., Makrodimitri, Z.A., Fleys, M.S.H., Chen, J., van der Laan, G.P.,... Fröba, A.P. (2016). Diffusivities of Ternary Mixtures of n-Alkanes with Dissolved Gases by Dynamic Light Scattering. Journal of Physical Chemistry B, 120(41), 10808-10823. https://doi.org/10.1021/acs.jpcb.6b08117

MLA:

Heller, Andreas, et al. "Diffusivities of Ternary Mixtures of n-Alkanes with Dissolved Gases by Dynamic Light Scattering." Journal of Physical Chemistry B 120.41 (2016): 10808-10823.

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