Direct determination of three-phase contact line properties on nearly molecular scale

Author(s)
P. M. Winkler, R. L. McGraw, Paulus Bauer, C. Rentenberger, Paul Wagner
Abstract

Wetting phenomena in multi-phase systems govern the shape of the contact line which separates the different phases. For liquids in contact with solid surfaces wetting is typically described in terms of contact angle. While in macroscopic systems the contact angle can be determined experimentally, on the molecular scale contact angles are hardly accessible. Here we report the first direct experimental determination of contact angles as well as contact line curvature on a scale of the order of 1nm. For water nucleating heterogeneously on Ag nanoparticles we find contact angles around 15 degrees compared to 90 degrees for the corresponding macroscopically measured equilibrium angle. The obtained microscopic contact angles can be attributed to negative line tension in the order of -10(-10) J/m that becomes increasingly dominant with increasing curvature of the contact line. These results enable a consistent theoretical description of heterogeneous nucleation and provide firm insight to the wetting of nanosized objects.

Organisation(s)
Aerosol Physics and Environmental Physics, Physics of Nanostructured Materials
Journal
Scientific Reports
Volume
6
No. of pages
7
ISSN
2045-2322
DOI
https://doi.org/10.1038/srep26111
Publication date
05-2016
Publication status
Published
Peer reviewed
Yes
Austrian Fields of Science 2012
103020 Surface physics
Keywords
HETEROGENEOUS NUCLEATION, TENSION, NUCLEUS, SIZE, NANOPARTICLES, PARTICLES, SURFACES, WATER, ANGLE, WORK
Portal url
https://ucris.univie.ac.at/portal/en/publications/direct-determination-of-threephase-contact-line-properties-on-nearly-molecular-scale(7d3fae0c-7151-4baa-8a5b-0ec4843ed30d).html