Revealing the Effects of Weak Surfactants on the Dynamics of Surface Fluctuations by Surface Light Scattering

Koller TM, Kerscher M, Köksal A, Stockerl M, Klein T, Fröba AP (2023)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2023

Journal

Journal of Physical Chemistry B American Chemical Society

Book Volume: 127

Pages Range: 10647-10658

Journal Issue: 49

DOI: 10.1021/acs.jpcb.3c06309

Abstract

Surfactant monolayers at liquid interfaces induce a viscoelastic behavior that influences the dynamics of surface fluctuations probed by surface light scattering (SLS). Recent thermophysical property research on viscosity and interfacial tension of liquid organic hydrogen carrier (LOHC) systems based on diphenylmethane suggested that such viscoelastic effects may also be present here, although not being expected a priori. To prove the hypothesis that the LOHC intermediate cyclohexylphenylmethane (H6-DPM) can induce a surfactant-like behavior, binary mixtures of diphenylmethane (H0-DPM) or dicyclohexylmethane (H12-DPM) with small amounts of H6-DPM were studied by SLS in combination with conventional viscometry and tensiometry and molecular dynamics simulations between (303 and 473) K. Only in mixtures with H0-DPM which has a slightly larger surface tension than H6-DPM, the presence of the latter compound causes a significant effect on the dynamics of surface fluctuations, especially on their damping. In analogy to the concentration-dependent behavior observed for a monolayer of a highly amphiphilic ionic surfactant on the surface of water at ambient temperature, the orientation of H6-DPM molecules with respect to the surface appears to change from a preferentially perpendicular to a parallel alignment with increasing temperature. This demonstrates that viscoelastic effects including accompanied surface orientation effects can be resolved by SLS even for weakly asymmetric surface-active molecules such as H6-DPM in its diluted mixtures with very similar species.

Authors with CRIS profile

Thomas Manfred Koller Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Manuel Kerscher Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Anil Köksal Sonderforschungsbereich 1411 Produktgestaltung disperser Systeme / Design of Particulate Products Tobias Klein Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Andreas Paul Fröba Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP)

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies

Related research project(s)

Thermophysical properties of the LOHC system for conditions related to high-performance release of hydrogen Emissionsfreier und stark emissionsreduzierter Bahnverkehr auf nicht-elektrifizierten Strecken Jan. 1, 2019 - Dec. 31, 2023

How to cite

APA:

Koller, T.M., Kerscher, M., Köksal, A., Stockerl, M., Klein, T., & Fröba, A.P. (2023). Revealing the Effects of Weak Surfactants on the Dynamics of Surface Fluctuations by Surface Light Scattering. Journal of Physical Chemistry B, 127(49), 10647-10658. https://dx.doi.org/10.1021/acs.jpcb.3c06309

MLA:

Koller, Thomas Manfred, et al. "Revealing the Effects of Weak Surfactants on the Dynamics of Surface Fluctuations by Surface Light Scattering." Journal of Physical Chemistry B 127.49 (2023): 10647-10658.

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