This example dataset is produced by calculating the BE_RPA using 300 data points, qmin = 0.001 Å-1, qmax = 0.7 (Å-1) and the above default parameter values.
MODEL
Borue-Erukhimovich RPA
AUTHOR/MODIFICATION
G. Nisato 30 NOV 1998
Alan Munter 08 JULY 1999, converted to Java
APPROVED FOR DISTRIBUTION
DESCRIPTION
Calculates the form factor, P(q), in the Borue-Erukhimovich random phase approximation (RPA) for a system of linear polyelectrolytes.
Resolution smeared version is also provided.
VARIABLES
Input Variables (default values):
| Parameter | Variable | Value |
|---|---|---|
| 0 | K (barns) | 10.0 |
| 1 | Lb (Å) | 7.1 |
| 2 | h (Å-3) | 12.0 |
| 3 | b (Å) | 10.0 |
| 4 | Cs (mol/L) | 0.0 |
| 5 | alpha | 0.05 |
| 6 | C (mol/L) | 0.7 |
| 7 | Incoherent Background (cm-1) | 0.0 |
USAGE NOTES
The function calculated is:
K = contrast factor of the polymer (barns = 10-24 cm2) = a2 with: a = (bp - vp/vsolvent * bsolvent)
where: bp = Sum of the scattering lengths of the atoms constituting the Monomer of the polymer under consideration
vp = partial molar volume of the polymer
vsolvent= partial molar volume of the solvent
Lb = Bjerrum length(Å)
This parameter needs to be kept constant for a given solvent and temperature!
h = virial parameter (Å3)
See Ref. (1) for the correct interpretation of this parameter. It incorporates second and third virial coefficients and can be negative.
b = monomer length (Å)
Cs = concentration of monovalent salt (mol/L)
Alpha = ionization degree : ratio of charged monomers to total number of monomers
C = polymer molar concentration (mol/L)
Bkd = Background
The returned value is in units of [cm-1]
REFERENCES
Borue, V. Y.; Erukhimovich, I. Y. Macromolecules 21, 3240 (1988).
Joanny, J.-F.; Leibler, L. Journal de Physique 51, 545 (1990).
Moussaid, A.; Schosseler, F.; Munch, J.-P.; Candau, S. J. Journal de Physique II France 3, 573 (1993).
Raphaël, E.; Joanny, J.-F. Europhysics Letters 11, 179 (1990).
TEST DATASET
This example dataset is produced by calculating the BE_RPA using 300 data points, qmin = 0.001 Å-1, qmax = 0.7 (Å-1) and the above default parameter values.