Those membranes offer efficient hydrogen separation, by hindering the hydrogen pore diffusion
through the selective adsorption of hydrocarbons.
This hypothesis also has valid stand as surface diffusion has been evoked to explain the too high cation flux in fully saturated conditions, compared to what can be predicted from a simple pore diffusion
model using water diffusion coefficient [16-18].
6c) indicates the effect of pore diffusion
. The general features of an initial steep linear portion and plateau are attributed to the bulk diffusion; intra-particle diffusion and the plateau portion represent the equilibrium.
This implies that the diffusion mechanism of MG dye onto NOAC is operated by pore diffusion
which is the only rate controlling step and not film diffusion.
The kinetics of adsorption was analyzed using pseudo-first-order and pseudo-second-order models and Elovich and Bangham's pore diffusion
models as described in the literature [50-52] and also in our previous works [16,20,21].
The expression used here for determining [eta] is valid for systems where pore diffusion
is dominant, that is, intermediate values of [phi].
In order to apply moment analysis to a pulse response curve to estimate linear adsorption constants or partition coefficients, and free and effective diffusion coefficients, the following assumptions are made: i) the mobile phase is a dilute solution; ii) velocity is constant throughout column cross-section; iii) no chemical reactions occur; iv) Henry's law describes solute uptake linear isotherm; v) intraparticle diffusion is described by pore diffusion
; vi) external mass transfer from the bulk liquid to the pores is described by film mass transfer; vii) axial dispersion effects are considered.
Investigation of pore diffusion
hindrance of monoclonal antibody in hydrophobic interaction chromatography using confocal laser scanning microscopy.
D = effective pore diffusion
coefficient in spherical pellets, [m.sup.2]/s
This suggests that the overall mechanism of reaction is predominantly pore diffusion
The definition of a pore diffusion
coefficient partially overcomes this problem.
and, assuming the accessible porosity equals the total porosity [[eta].sub.tot], the pore diffusion
coefficient [D.sub.p] ([m.sup.2]/s)