Absorption
  Models absorption (by diffusion and relaxation) versus time. Under reconstruction
2025.Feb.19 21:23:02
xF Weight of Fickian diffusion (fraction, in [0–1]).
kF, kR s−1 Diffusivity rate, relaxation rate (both T−1).
d m Diameter of particle (L).
h, tfin s Print step, final time (both T).
vsSqrt Plot vs. √t.
Show values Show the graph coordinates.
 Absorption, as applied to a "spherical" particle of a superabsorbent polymer, is considered by Fickian diffusion and relaxation. The particle diameter is d, xF is the fraction ("weight") undergoing Fickian diffusion (1−xF, relaxation), and kF and kR are the respective absorption rates.
References: Plate: Diffrela030706

• Rosa, F., J. Bordado, M. Casquilho, 2002, "Kinetics of water absorbency in AA/AMPS copolymers: applications of a diffusion-relaxation model", Polymer, 43, pp 63-70 (doi10.1016/S0032-3861(01)00596-1).

• Rosa, F., J. Bordado, M. Casquilho, 2007, "Polímeros superabsorventes: potencialidades e aplicações" (pdf, class="decnone">=), Ingenium, 98, pp 156-158.

• Abramowitz, M., and I. A. Stegun, Handbook of mathematical functions", 10.th printing, Nat'l Bureau of Standards (USA), now NIST, Nat'l Inst. of Standards and Technology. (Google search... downloadable)

• Fick, Adolf Eugen (1828-04-01–1901-08-21): Fick's law of diffusion Wikip., Google search...

• 1910-07-06: Collatz, Lothar, birthday.

 
 
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Created: 2003-07-06 — Last modified: 2016-07-05