Chemistry Reference
In-Depth Information
Fig. 3.
Measured static surface elasticity (solid lines) as a function of surface pres-
sure for the three surface films of Figures 3 and 4. Solid symbols are elasticity
values predicted for the three films from their mass spectra using the LDA-derived
D1 scores and the linear relations in Table 2. The shaded area indicates the over-
all range of elasticity values observed for the suite of 30 microlayer
4. Summary
In the absence of a rigorous theoretical model for multicomponent surface
films, an empirical method for relating the composition and molecular
structure of complex natural surface films to interfacial physical properties
has been explored. The method combines chemical and structural data with
statistical analysis. The advantages of this approach are that (1) it facili-
tates identification of the end-member components in complex mixtures
that determine the elasticity of microlayer films and (2) allows reasonably
accurate estimates of static elasticity from surface pressure and the mass
spectrum of the microlayer SAOM. This approach will be extended in fu-
ture work to
in situ
mapping of slick composition and surface elasticity by
coupling advanced ion trap mass spectrometers, which are capable of de-
tecting and measuring individual film components in unresolved mixtures,
with continuous microlayer sampling.
