where Wt is the water uptake at time t; We2 is the theoreti- cal equilibrium water uptake for second-order kinetic; and k2 is the specific rate constant for the second-order swelling kinetic. The fitting of the experimental data by the second-order swelling model was evaluated by the coefficient of determination [r2, (Foo
k2W2 t
Wt = e2
1 + We2k2t
(4) & Hameed, 2010)]. The model calculations were illustrated in relaxation in the network of beads