Eyring Equation for Viscosity
(Hiementz-96)
-
k
is Boltzmann's constant and
T
is temperature.
is a cluster of constants:
-
is the distance over which the displacement occurs (Hiementz-94)
-
is the forward distance a molecule moves in a single flow step
(Hiement-94)
-
the frequency of the steps (Hiementz-94)
(I assume this has the units of reciprocal time...)
is the frequency at which
molecules cross the energy barrier. (Hiementz-92)
Eyring based his theory on the idea that there was an energy barrier to
transcend for a polymer motion to occur. That's what I get out of
reading Hiementz-91. Below we see a formula which defines K(R) as a
function of A.
We've already defined k(R) as the frequency at which "steps"
occur. A is the frequency at which steps occur at infinite temperature.
This follows from the math above, for we can make the exponent term go
to 1 by making (- Delta epsilon* / kT) go to zero, and we can do that
by making kT infinitely large, and since, k is constant only T remains
for us to manipulate. (breathe)
is the rate of shear (Hiementz-77)
Last Update- September 11, 1995- wld