Surface diffusion of direct dyes in porous cellulose membranes

Intraparticle diffusion of phosphates in OH‐type strongly basic ion exchanger

“…They also studied an intraparticle mass transfer in a bidispersed porous ion exchanger by mutual ion exchange . To prove a parallel transport of surface and pore diffusions, extensive studies on the mass transport of various direct dyes through porous cellulose membranes were previously conducted (Gutsche and Yoshida, 1994;Maekawa et al, 1989;Nango et al, 1989;Yoshida et al, 1986Yoshida et al, , 1989Yoshida et al, , 1991. They measured not only uptake curves but also concentration profiles and theoretically proved the existence of a parallel transport by using the experimental uptake curves and concentration profiles.…”

Effects of sulfonated surfactants on parallel diffusion of mono azo dye with high aggregation constant into cellulose membranes

“…The thickness of the water‐swollen membrane ( l ) was 38.6 μm as measured by a membrane‐thickness meter (Kohbunshi Keiki Co., Ltd.). The void fraction (ϵ P ) and the volume per unit dry cellulose ( V ) in a water‐swollen state were 0.733 and 2.38 dm 3 /kg, respectively, as measured by the pycnometric method 3…”

“…In our previous articles1–9 we elucidated the diffusion behavior of sulfonated dyes into the water‐swollen cellulose membranes on the basis of the parallel diffusion model, which consists of surface and pore diffusion. It was revealed that the dye molecules diffuse in parallel on the surface of the pore wall and in the pores of the cellulose.…”

Pretreatment of Corn Stover with Twin-Screw Extrusion Followed by Enzymatic Saccharification

“…Congo red is a direct dye. It was proposed that the Langmuir isotherm can satisfactorily model the adsorption of direct dyes onto cellulose substrates at very low concentrations [34]. The prerequisites for Langmuir adsorption include the formation of a monolayer, thus the SSA can be derived from the maximum amount of adsorption of the dye [25].…”