Viscosity, self-diffusion coefficients and PFG-LED NMR
Choose solvent/temp first
Solvent
Temp
Viscosity
Use
------------ Water ------------
Water
20
o
C
0.01002
Water
99
o
C
0.002848
----------- Organic -----------
Ether
20
o
C
0.00233
Chloroform
20
o
C
0.0058
Methyl alcohol
20
o
C
0.00597
Benzene
20
o
C
0.00652
Ethyl alcohol
20
o
C
0.012
Benzyl ether
20
o
C
0.0533
Glycol
20
o
C
0.199
Glycerin
20
o
C
149.0
Stokes eqn D
S
=k
B
T/6πηR
Viscosity
Poise
Temperature
Kelvin
Diff. Coeff.
cm
2
/s
Radius
nm
for R = f/D
s
, current f =
= k
B
T/6πη
USEFUL INFO:
During time τ =
seconds
molecules travel sqrt(2Dτ) =
nm
DIFFUSION CONTROLLED RATE
for the given solvent (i.e. viscosity)/temperature
k
d
= 8RT/3η x 10
4
L mol
-1
s
-1