Diffusivity of oxygen into carriers entrapping whole cells

The effective diffusivity of oxygen, D e , in Ca‐alginate and PVA–SbQ gels was measured using a two‐chamber vessel with a membrane between the two chambers. The effect of cell density, C c , on D e in Ca‐alginate gels was studied. The effective diffusivity of oxygen decreased with increasing cell density, to C c = 170 kg dry cells/m 3 gel. The dependency of D e on cell density was discussed in terms of a random‐pore model. The model correlated well with experimental data, i.e., kD e / D 0 = 0.86(1 − 1.47 × 10 −3 C c ) 2 . Here, k is the partition coefficient, and D 0 is diffusivity in water.