A Rapid Analysis of Ultrafiltration Membrane Structure

Abstract

Abstract The possibility of using protein calibration data for rapid analysis of ultrafiltration membrane structure is discussed. It is shown that structure analysis based on calibration data gives the possibility of determining the mean membrane pore radius, and the view of distribution of pores by size, to reveal and to asses the microscopic membrane defectness, to estimate the thickness of selective layer, and also to correlate the structure of investigated membrane with that of the principal serial ultrafilters. Beside this, the use of permeability data obtained during protein calibration gives the possibility to assess the hydrophilicity of membrane investigated. However, the principal advantage of this method is high productivity and the possibility to perform the analysis with the use of the simplest ultrafiltration and gel chromatographic equipment. The examples of the use of membrane structure analysis in the course of development of composite polysulphoamide membranes and track‐etched ultrafilters are given. Keywords: Ultrafiltrationmembrane structurepore sizedistribution of pores by sizedefectnessthickness of selective layerhydrophilicity Notes 1By selective properties we mean the ability of ultrafiltration membrane to separate the solutes differing in molecular masses (sizes of molecules). 2The last condition must ensure the establishment of stationary permeate flow, i.e., the formation of equilibrium gel layer on membrane surface. 3The values of R0 were determined by manufacturer by gas permeability. 4One must say that this assumption is usually not explicitly used in investigations devoted to the determination of membrane PSD from retention experiments [see, for instance Citation29 Citation30]. 5The logarithmic normality of UF membranes retention curves is a direct consequence of logarithmic normality of distribution of membrane pores by size in combination with a rigorous sieving mechanism. In its turn, logarithmically normal distribution by size is characteristic of disperse systems of condensation type (fog, smog, hoarfrost, snowflakes, etc.) to which porous polymeric membranes relate. 6For instance, in Citation38 Equationeq. (12) was successfully used for analysis of dynamic viral‐protein membrane which appeared in the course of anti‐influenza vaccine microfiltration. 7Π2 value is equal, similarly to D2, to the ratio of water flux through defects to total water flux through membrane.