TY - JOUR
T1 - Concentration polarization phenomena during dead-end ultrafiltration of protein mixtures
T2 - The influence of solute-solute interactions
AU - van den Berg, G.B.
AU - Smolders, C.A.
PY - 1989
Y1 - 1989
N2 - The flux decline behaviour of some charged proteins and of binary mixtures of charged solutes during unstirred dead-end ultrafiltration has been studied. The mixtures consisted of the proteins bovine serum albumin, (BSA), α-lactalbumin and/or lysozyme. Of special interest were α-lactalbumin and lysozyme because these proteins are physico-chemically identical, except for the sign of their charge at the conditions used (pH = 7.4, I=0.125 N and T=20°C). The ultrafiltration properties were studied using the boundary layer resistance model. Ultrafiltration of single protein solutions of α-lactalbumin and of lysozyme showed identical characteristics. The fouling behaviour during ultrafiltration of binary mixtures of the three components appeared to be dependent on both the charge of the solutes and the (unequal) dimensions of the solutes. A mixture of oppositely charged proteins (i.e., BSA/lysozyme or α-lactalbumin/lysozyme) sometimes showed a considerable increase of the resistance of the concentrated layer near the membrane, depending on the mixing ratio of the two proteins. When equally charged (i.e., BSA/α-lactalbumin) proteins are ultrafiltered, a small decrease of the resistance could be observed, again depending on the mixing ratio of the proteins. The charge of the proteins, especially opposite charges, appeared to influence the flux behaviour more than the slightly denser packing of the solutes (as a result of unequal dimensions) would account for.
AB - The flux decline behaviour of some charged proteins and of binary mixtures of charged solutes during unstirred dead-end ultrafiltration has been studied. The mixtures consisted of the proteins bovine serum albumin, (BSA), α-lactalbumin and/or lysozyme. Of special interest were α-lactalbumin and lysozyme because these proteins are physico-chemically identical, except for the sign of their charge at the conditions used (pH = 7.4, I=0.125 N and T=20°C). The ultrafiltration properties were studied using the boundary layer resistance model. Ultrafiltration of single protein solutions of α-lactalbumin and of lysozyme showed identical characteristics. The fouling behaviour during ultrafiltration of binary mixtures of the three components appeared to be dependent on both the charge of the solutes and the (unequal) dimensions of the solutes. A mixture of oppositely charged proteins (i.e., BSA/lysozyme or α-lactalbumin/lysozyme) sometimes showed a considerable increase of the resistance of the concentrated layer near the membrane, depending on the mixing ratio of the two proteins. When equally charged (i.e., BSA/α-lactalbumin) proteins are ultrafiltered, a small decrease of the resistance could be observed, again depending on the mixing ratio of the proteins. The charge of the proteins, especially opposite charges, appeared to influence the flux behaviour more than the slightly denser packing of the solutes (as a result of unequal dimensions) would account for.
U2 - 10.1016/S0376-7388(00)80857-1
DO - 10.1016/S0376-7388(00)80857-1
M3 - Article
SN - 0376-7388
VL - 47
SP - 1
EP - 24
JO - Journal of membrane science
JF - Journal of membrane science
IS - 1-2
ER -