Abstract
Highly dipolar molecules become orientationally ordered in the vicinity of a surface due to the electrostatic interaction with their image dipoles. We study this orientational order alpha(2) at the noncritical liquid-vapor interface of critical dipolar+nonpolar mixtures using ellipsometry. The dipolar molecules, which are strongly desorbed from the interface, possess an orientational order which is well described by alpha(2) approximately -t(2beta)D(+/-)(z/xi), where t=|T-T(c)|/T(c) is the reduced temperature relative to the critical temperature T(c), D(+/-) is a universal function of the distance z and the surface correlation length xi=xi(s)(o+)t(-nu), while beta=0.328 and nu=0.632 are standard critical exponents. The dipoles, which are preferentially oriented parallel to the surface, are repelled by their image dipoles, where xi(s)(o+)>xi(b)(o+) (the bulk correlation length amplitude).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Physical review. E, Statistical, nonlinear, and soft matter physics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.