12-01
Monolayer
and aggregate formation of a modified phthalocyanine
on mica determined by a delicate balance of surface interactions, Surface
Science 606 (2012) 830-835
F.J. van den
Bruele, W. de Poel, H.W.M. Sturmans,
S. Pintea, R. de Gelder, D. Wermeille,
M. Juríček, A.E. Rowan, W.J.P. van Enckevort and E. Vlieg
Abstract:
An ordered layer of a phthalocyanine modified with
ether tails can be formed onmuscovite mica if removed
from solution and dried. This ordered layer forms on potassium terminated as
well as on sodium terminated mica, but not on a hydronium
terminated surface. The molecules lie flat on the surface, as shown by AFM and
X-ray diffraction, giving a layer thickness of approximately 1 nm. In
solution, however, no in-plane ordering exists. The material is attracted to
the substrate surface but instead of ordering, it aggregates in a liquid-like
mobile fashion. This is likely caused by the fact that the water present in
solution has a stronger interaction with the potassium ions on the mica surface
than with the ether tails of the phthalocyanine.