The dialysis membrane is a key component of the haemodialyser. Determination of the membrane solute permeation and ultrafiltration characteristics is important in predicting haemodialyser performance. In some membrane permeation test cells, there are additional mass transfer resistances present due to fluid films adjacent to the membrane surface. This can mask the true permeability of the membrane. Test cell designs should therefore seek to minimise or eliminate any fluid film resistances In this project, solute permeability results were compared using two types of permeation test cells, namely a radial flow cell and a dynamic test cell. In the radial flow cell, fluid streams are directed perpendicular to the membrane surfaces in an attempt to reduce the fluid film thickness. In the dynamic test cell, the fluid streams are passed at high velocity through an open-pore rigid metal support structure that generates localised mixing at the membrane surfaces. Fluid film resistances are proportionately greater for the transfer of low molecular weight solutes and for high flux membranes. Therefore, the transfer of urea (60 mol wt) was studied in a polyacrylonitrile-based membrane AN69ST. Permeability of a higher molecular weight solute, caffeine, (194.2 mol wt) was also determined.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:502354 |
| Date | January 2008 |
| Creators | Ebdiwi, Nouri |
| Publisher | University of Strathclyde |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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