Chemistry Reference
In-Depth Information
acid methyl ester (methyl
Z
-9-octadecenoate; OLME), and methyl palmi-
tate (methyl hexadecanoate; PME), see Figure 2.
(a)
CH
3
HO
O
CH
3
(b)
H
3
C
O
O
CH
3
(c)
H
3
C
O
Fig. 2.
Chemical structures of typical slick-forming compounds, a.) oleyl alcohol
(
Z
-9-octadecen-1-ol; OLA), b.) oleic acid methyl ester (methyl
Z
-9-octadecenoate;
OLME), and c.) methyl palmitate (methyl hexadecanoate; PME)
By the way of contrast, crude oil spills mainly consist of alkanes (“
par-
affins
”), cycloalkanes, and aromatic compounds, i.e., chemicals that exclu-
sively exhibit a hydrophobic character, because no hydrophilic head group
is present. As a consequence, a small drop of high-boiling paraffin oil,
placed onto the water surface, maintains its form as a drop, floating in a
depression as shown in Figure 3. Depending on the amount and the viscos-
ity of the crude oil mixture as well as on the specific environmental condi-
tions the drop will leave this idealised form, flattens out and becomes thin-
ner. However, the final thicknesses thus achieved still remain orders of
magnitude larger than those of a monomolecular film shown in Figure 1.
air
paraffin oil
water
Fig. 3.
Simplified representation of a drop of high-boiling (= long-chain) paraffin
oil lying on a water surface
