Separation of aqueous solutions of nonionic organic solutes by ultrafiltration

Diffusive and convective protein transport through asymmetric membranes

“…The results were well described by an inverse dependence of pore length on the cube of the solute diameter, although there is no independent justification for this type of dependence. Tsapuik et al (1990) recently measured the sieving coefficient of several small solutes (MW 92 to 342) and polyethylene glycols (MW 400 to 40,000) through cellulose acetate, polysulfonamide, and track-etched polyethylene terephthalate membranes. The results were consistent with the flux dependence given by Eq.…”

“…No comparison with hydrodynamic theory was presented. Instead, Tsapuik et al (1990) analyzed the data by assuming that S, = + and that D,,,/D, = 4'. The effective membrane thickness (6,) was then evaluated from the sieving data for each solute using Eq.…”

Evaluation of dialysis membranes using a tortuous pore model

“…Nakao and Kimura (1981) applied the straight pore model to the analysis of data from ultrafiltration experiments, and reported that the value of the parameter A,/Ax in the model increased by the third power of the solute's Stokes radius. Tsapuik et al (1990) found that effective membrane thickness decreased as molecular weight increased for cellulose acetate membranes, but the effective membrane thickness was independent of molecular weight for track-etched membranes. Unlike the straight pore model, however, this study did not account for the friction factor.…”

Review of Dynamic Membranes

“…Further analysis of these results in terms of friction factors in the system provides additional information about the interaction of the two solutes with each other and with the solvent and membrane interface (Szaniawska and Spencer 1997). Xu and Spencer (1997a) applied a one-dimensional fine-porous ultrafiltration membrane model by Tsapiuk et al (1990) to the nanofiltration of salts and dyes by dynamic membranes. Since the model is one-dimensional, it does not take into account interactions between different solutes in the system.…”

“…Since the model is one-dimensional, it does not take into account interactions between different solutes in the system. According to the model the rejection, r, is given as (Tsapiuk et al 1990 where Pe,,, is the internal Peclet number (J/k m ), Pe, is the external Peclet number (J/k s ), k m is the solute mass transport coefficient in the active layer of the membrane and k s is the solute mass transport coefficient in the concentration layer. Nanofiltration experiments were performed with single electrolyte solutions on membranes similar to those described by Szaniawska and Spencer (1994) in order to calculate the parameters k m , k, and σ.…”