Measurement of the transmittance coefficient spectrum of Cuprophan and RP69 membranes: applications to middle molecule removal via ultrafiltration.

The transmittance coefficients of Cuprophan PT-150 and Rhone-Poulenc AN69 have been defined over a broad MW range. The results can be completely characterized by a simple Gaussian distribution employing 2 parameters, the selectivity and the mean molecular diameter. The selectivities of the membranes studies are identical. The mean MW at 50% cutoff for Cuprophan and RP69 are 2,500 and 11,500, respectively. A membrane model illustrating a semi-empirical correlation between permeability and transmittance has been developed.