Biomedical Engineering Reference
In-Depth Information
Fig. 10
Representative SLS power spectra from water at 25
◦
C. The three diffraction
orders, 4th, 5th and 6th, correspond to
k
= 26295, 32431 and 38 548 m
-1
, respectively. The
frequency shift for the 4th order is indicated by
f
s
while the full width at half-maximum
intensity for the 5th order is indicated by
∆
f
s
Fig. 11
Π
and
ε
s
vs.
A
isotherms for PVAc on water at 23
◦
C. Surface pressure
Π
(represented
by the
circles
)andthestaticelasticity
ε
s
(represented by the
solid curve
)areplottedasafunc-
tion of area per monomer. The
open circles
at large
A
correspond to good solvent conditions.
The
filled circles
correspond to the region of increasing
ε
s
as well as deviation from a power
law scaling. The
open circles
at small
A
correspond to a collapsing film
Two other technical issues must be discussed briefly. In deducing the vis-
coelastic parameters through the dispersion equation from the power spec-
trum of SLS, it must be corrected for the instrumental broadening. The other
