Molecular weight cutoff values ultrafiltration

Other separators and membranes. The observation that cations or anions can help to maintain charge in an MFC opens the door to new possibilities for using different types of membranes in MFCs. The main function of the membrane is to keep solutions isolated while allowing charge transfer, presumably via small ions. Thus, ultrafiltration (UF) membranes—especially those developed for wastewater applications—may be suitable for use in MFCs. These membranes have tiny pores, with many membranes available that have molecular weight cutoff values below 1000 daltons (IK). UF membranes have appreciable flow through them only under high pressure, and thus under relatively low... 

The retention properties of ultrafiltration membranes are expressed as Molecular Weight Cutoff (MWCO). This value refers to the approximate molecular weight (MW) of a dilute globular solute (i.e., a typical protein) which is 90% retained by the membrane. However, a molecule s shape can have a direct effect on its retention by a membrane. For example, linear molecules like DNA may find their way through pores that will retain a globular species of the same molecular weight. 

Membrane Pore Diameter or Molecular Weight Cutoff. The value of membrane pore diameter will have a major influence on the permeation and separation characteristics for most process filtration applications. The intrinsic membrane permeability is related to the pore diameter for many microfiltration membranes whereas, for ultrafiltration membranes, it is typically indicative of the solute retention properties. Tables 8 and 9 provide typical permeability and retention data for many common MF and UF membranes, respectively.f t ... 

---