Quantification of the Structure of Colloidal Gas-Liquid Interfaces

Mark Vis; Kelly J H Brouwer; Álvaro González García; Andrei V Petukhov; Oleg Konovalov; Remco Tuinier

doi:10.1021/acs.jpclett.0c02464

Quantification of the Structure of Colloidal Gas-Liquid Interfaces

J Phys Chem Lett. 2020 Oct 1;11(19):8372-8377. doi: 10.1021/acs.jpclett.0c02464. Epub 2020 Sep 21.

Authors

Mark Vis^{1

2}, Kelly J H Brouwer^{1

2

3}, Álvaro González García^{1

2

3}, Andrei V Petukhov^{1

3}, Oleg Konovalov⁴, Remco Tuinier^{1

2}

Affiliations

¹ Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
² Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
³ Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Utrecht University, 3508 TA Utrecht, The Netherlands.
⁴ European Synchroton Radiation Facility, 38000 Grenoble, France.

Abstract

We have quantified the structure of the colloidal gas-liquid interface using synchrotron X-ray reflectivity measurements on a model colloid-polymer mixture. The interfacial width shows mean-field scaling with the colloid density difference, and the density profiles appear to be monotonic. Furthermore, our measurements allow us to distinguish between different theoretical polymer descriptions commonly used to model colloid-polymer mixtures. Our results highlight the importance of capturing the correct polymer physics in obtaining a quantitative theoretical description of the colloidal gas-liquid interface.