Predictability of performance of reverse osmosis membranes from data on surface force parameters

Determination of interaction forces and average pore size and pore size distribution and their effects on fouling of ultrafiltration membranes

“…Since force constants B and D are available for the BSA-polymer-water system in Table II, the membrane performance data such as the separation of BSA solute and (PR)/(PWP) ratio can be calculated for PS-V-1, CA-400-5, and PPPH 8273-2 membranes, the average pore size and the pore size distribution of which are given in Table I, under given operating conditions. The theories and analytical procedures have been fully developed in our earlier papers (Matsuura and Sourirajan, 1981;Matsuura et al, 1981a) and summarized in our recent work (Matsuura et al, 1982;Sourirajan and Matsuura, 1982). Briefly, the surface force-pore flow model, on which the calculation is based, assumes straight cylindrical pores.…”

“…The quantity d indicates the distance between polymer surface and the center of the macromolecular solute. The data on the surface excess obtained by applying eq A-l to the chromatography experimental result can be related to the potential function by (Matsuura et al, 1982) r/cb = C (ß~ / -1) d(d) (A-3) ''D™, By equating D as a first approximation, to the size of the macromolecular solute, such as Stokes' law radius, the force constant B can be calculated by using eq A-2 and eq A-3 in conjunction with the experimental value for F/cb. The values for /cb, D and B so obtained are listed in Table for several synthetic macromolecular solutes with respect to polymers used in this study.…”

Effect of Polymer Membrane Material on Reverse Osmosis Separations of Free Radicals in Aqueous Solutions

“…An exactly identical experimental result was obtained in the previous work ( 3 ) . This is due to the very strong attractive interaction force between Solute VII and CA-398 material and the relatively large size of the pore existing in the membrane cellulose acetate material (15). Although there are other cases where the solute is preferentially adsorbed to the polymer material (all radical solutes with respect to CA-398 material and radical Solute VI and nonionized Solute VII wi1.h respect to PPPH 8273 material), the solute separation increases with the increase in the operating pressure, since the strong attraction is compensated for by the steric hindrance effect.…”

Effect of shrinkage on pore size and pore size distribution of different cellulosic reverse osmosis membranes

“…The control of the average pore size and the pore size distribution on the membrane surface in the membrane formation process has a major effect on the performance data of the membrane produced, such as pure water permeation rate, product rate, solute separation, fractionation of different solutes, and membrane fouling in the RO/UF processes (Chan et al, 1982(Chan et al, ,1984a(Chan et al, , 1984bLiu et al, 1984; Matsuura et al, 1984; Matsuura and Sourirajan, 1983; Sourirajan and Matsuura, 1982;Taketani et al, 1983). In view of its importance, the changes of the average pore size and the pore size distribution during the shrinkage process of cellulose acetate (CA-398) membranes and also during the solvent evaporation process of aromatic polyamidohydrazide membranes were studied in our earlier work (Chan et al, 1984a,b) by determining the average pore size and the pore size distribution of membranes on the basis of the surface force-pore flow model for reverse osmosis transport.…”