Ultrafiltration of colloidal solutions containing L, D-phenylalanine, trans-4-hydroxy-L-proline and their copper complexes Original Research Article

The effects of the composition of a surfactant colloidal solution containing nonylphenylpolyoxyethylene ether, theracemic mixture of L,D-phenylalanine, trans-4-hydroxy-L-proline and/or their copper complexes upon the flux of permeate and the resistance of the hydrophilic membrane and additional layer formed during ultrafiltration were studied. It was found that colloidal solutions containing the nonionic surfactant and additionally phenylalanine, the selector and their complexes with copper can be ultrafiltrated through hydrophilic membranes made of regenerated cellulose with a cut-off of 10 kDa with satisfactory fluxes. Both the permeate flux and resistance depend upon the concentration of the surfactant, but the effect of phenylalanine and the selector is negligible. The decisive effect was observed for copper complexes with phenylalanine and the selector as the complexes significantly decrease the permeate flux and increase the resistance of the additional layer.