X-ray Reflectivity Study of Thermal Capillary Waves and the Interfacial Profiles of Water-Alcohol Mixtures

ORAL

Abstract

The liquid/vapor interfaces of water-alcohol (methanol, ethanol, and propanol) mixtures were investigated by X-ray reflectivity. Analysis of X-ray reflectivity data shows that the interfacial widths (surface roughnesses) of all mixtures at a fixed temperature depend solely on the surface tension of the mixture, and the intrinsic surface roughness is on the order of inter-atomic distances, and within error, independent of solution constituents. The implications of our results in the regard to the origin of the intrinsic roughness and the capillary wave-vector cutoffs applicable to X-ray scattering will be discussed.

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Authors

  • Yoonnam Jeon

    • Department of Physics and Program of Integrated Biotechnology, Sogang University, Seoul, Korea

  • Jaeho Sung

    • Department of Physics and Program of Integrated Biotechnology, Sogang University, Seoul, Korea

  • Doseok Kim

    • Department of Physics and Program of Integrated Biotechnology, Sogang University, Seoul, Korea

  • Wei Bu

    • Ames laboratory and Department of Physics and Astronomy, Iowa State University, USA

  • David Vaknin

    • Ames laboratory and Department of Physics and Astronomy, Iowa State University, USA