Noncapillary-Wave Structure at the Water-Alkane Interface

Dragoslav M. Mitrinović; Aleksey M. Tikhonov; Ming Li; Zhengqing Huang; Mark L. Schlossman

doi:10.1103/PhysRevLett.85.582

Noncapillary-Wave Structure at the Water-Alkane Interface

Dragoslav M. Mitrinović, Aleksey M. Tikhonov, Ming Li, Zhengqing Huang, and Mark L. Schlossman

Phys. Rev. Lett. 85, 582 – Published 17 July 2000

Abstract

Synchrotron x-ray reflectivity is used to study the interface between bulk water and bulk $n$ -alkanes with carbon numbers 6 through 10, 12, 16, and 22. For all interfaces, except the water-hexane interface, the interfacial width disagrees with the prediction from capillary-wave theory. The variation of interfacial width with carbon number can be described by combining the capillary-wave prediction for the width with a contribution from intrinsic structure. This intrinsic structure is determined by the gyration radius for the shorter alkanes and by the bulk correlation length for the longer alkanes.

Received 23 March 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.582

Authors & Affiliations

Dragoslav M. Mitrinović¹, Aleksey M. Tikhonov¹, Ming Li¹, Zhengqing Huang², and Mark L. Schlossman^1,3,*

¹University of Illinois at Chicago, Department of Physics, 845 West Taylor Street, Chicago, Illinois 60607
²Brookhaven National Laboratory, National Synchrotron Light Source, Upton, New York 11973
³University of Illinois at Chicago, Department of Chemistry, 845 West Taylor Street, Chicago, Illinois 60607