Designation	Description
Abbreviations
DBL	Diffusion boundary layer
NMP	N-methylpyrrolidone
PSF	Polysulfone
PVP	Polyvinylpyrrolidone
SEM	Scanning electron microscopy
Symbols
$C$	Concentration
CL	Clearance
$d$	Membrane thickness
$D$	Diffusion coefficient
$d_{hf}$	Inner diameter of the hollow-fiber membrane
$F$	Faraday constant
$f_p$	Volume fraction of pore space in the membrane
$J$	Flux density
$K$	Equilibrium chemical reaction constant
$k_1$ and $k_{-1}$	Dissociation and recombination rate constants, respectively, Equation (2)
$k_d$ and $k_r$	Dissociation and recombination rate constants for water, respectively
$L$	Mass transfer coefficient
$l_{hf}$	Effective length of the hollow-fiber membrane
$m$	Membrane mass
$N_{hf}$	Number of hollow-fiber membranes in the dialyzer
$P$	Membrane diffusion permeability
$R$	Gas constant
$S_{mb}$	Effective surface area of the hollow-fiber membrane in the dialyzer
$T$	Absolute temperature
$t$	Time
$V^A$ and $V^B$	Volume of the diluate and dialysate compartments, respectively
$W$	Mass fraction of water in the membrane
$WC$	Membrane water content
$x$	Coordinate normal to the membrane surface
$z$	Charge
Greek Symbols
$\alpha$	Structural parameter characterizing the arrangement of pores relative to the transport axis
$\delta$	Diffusion boundary layer thickness
$\rho$	Density of the dry membrane
$\phi$	Electric potential
Superscripts/subscripts
A	Diluate compartment
B	Dialysate compartment
dry	Dry state
sw	Swollen state