Chemistry Reference
In-Depth Information
the compression procedure, some disorder is induced within the mono-
layer. After stopping the compression, the molecules tend to arrange them-
selves such that an optimum order of the alkyl chains and of the head
groups is attained. This is largely the relaxation process that is also en-
countered on a slick-covered undulating water surface. With regard to the
PME films, it is well-documented >4@ that the ester head group performs a
“flip-flop”-like change in its orientation (the so-called
E/Z-
isomerisation).
As a consequence, the head group is prevented from hydration by the adja-
cent water layer during compression of the mono
layer, and,
vice
Fig. 3.
Morphology of a PME-film
spread of
n-
hexane as determined by
BAM;
Fig. 4.
Same as Fig. 3, but com-
pression status 0.24 nm
2
/molecule
compression
status
0.34
nm
2
/molecule; 1 mm = 100 Pm
Fig. 5.
Same as Fig. 3, but compression
status 0.20 nm
2
/ molecule
Fig. 6:
Morphology of a PME-film
spread of ethanol as determined by
BAM; compression status 0.415 nm
2
/
molecule; 1 mm = 100 Pm
