THERMODYNAMICS OF FORMATION OF POROUS POLYMERIC MEMBRANE BY PHASE-SEPARATION METHOD .6. SUPERMOLECULAR STRUCTURE AND VIRUS SEPARABILITY OF POROUS REGENERATED CELLULOSE MEMBRANE PREPARED BY PHASE-SEPARATION METHOD

An attempt was made (1) to correlate permeation properties such as fil tration rate. filtration coefficient, and critical filtration volume w ith filtration conditions of virus contaminated aqueous solutions thro ugh porous regenerated cellulose membrane, (2) to demonstrate possibil ity of complete rejection of viruses from filtrate, (3) to clarify the captured state of viruses in the membrane and the concentration distr ibution of the captured viruses to the direction of thickness of the m embrane. and (4) to propose the mechanism of capturing viruses with th e membrane by taking into account the membrane structure and a three-d imensional form of pores (i.e., morphology of pores). Porous regenerat ed cellulose membrane prepared by the phase separation method consiste d of the secondary particles of cellulose, and there exist large cavit ies and narrow veins connecting these cavities in the membrane. Most o f virus particles were trapped either in veins by the blocking or in c avities by the accumulation, but a very few of them flowed downstream and finally contaminated in filtrate. A ''critical filtration volume V -c [ml cm(-2)]'' was defined as total filtration volume obtained till the moment when the first virus reached to the opposite (i.e., rear) s ide of the membrane. Complete rejection of viruses from the filtrate w as achieved until total filtration volume reached V-c, which increased with the pressure difference Delta P and concentration of virus in th e filtrand c(0). Without exceeding its V-c, the porous cellulose membr ane will be one of possible membrana designed for the removal of virus from aqueous serum protein mixtures.