https://doi.org/10.1007/s100510050305
Anomalous adhesion in adsorbed polymer layers
1
Department of Applied Mathematics,
Research School of Physical Sciences and Engineering,
Australian National University, Canberra, ACT 0200, Australia
2
Institut Charles Sadron (CNRS UPR 22)
and University Louis Pasteur,
6 rue Boussingault, 67083 Strasbourg Cedex, France
3
Laboratoire de Chimie et de Physicochimie des Assemblages
Supramoléculaires
Organisés (CNRS URA 448) ,
Institut Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
Corresponding author: a Jean-Marc.DiMeglio@ics.u-strasbg.fr
Received:
12
November
1997
Accepted:
6
March
1998
Published online: 15 May 1998
Anomalous adhesion behaviour observed in the polydimethylsiloxane/heptane/silica system is reported. This behaviour is characterised by the infrequent appearance of one or more elastic minima which occur in addition to the ever-present primary adhesion. The resulting elastic force is attributed to loops connecting the tip to the substrate and can be described by two models; a worm-like chain, and a freely jointed chain. Both models give similar values for the characteristic segment length of around 0.24 nm and indicate that the chains have been extended by between 90 to 95% of their chain contour length before desorption. In some cases multiple adhesions were observed between tip and substrate and have been used to suggest a method for determining the distribution of adsorbed polymer loops.
PACS: 68.45.-v – Solid-fluid interfaces / 82.70.-y – Disperse systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998