Porosimetric characterization of polysulfone ultrafiltration membranes by image analysis and liquid–liquid displacement technique

Abstract

Structural and surface properties of two commercial polysulfone ultrafiltration membranes have been evaluated by different techniques. Pore size distributions have been determined by Liquid-Liquid Displacement Porosimetry (LLDP) as well as by image analysis performed onto Field Emission Scanning Electron Microscopy (FESEM) images of the membrane surfaces. Fourier Transform Infrared Spectroscopy (FTIR) has been used to investigate membrane composition, and in particular, to obtain proper information on the presence of additive within the membrane structure.Porosimetric results obtained by the two independent techniques compared reasonably well and the Molecular Weight Cut Off (MWCO) of the two membranes estimated from LLDP pore size distribution were found to be in good agreement with the nominal values given by manufacturers.

Comparison of Capillary Flow Porometry (CFP) and Liquid Extrusion Porometry (LEP) Techniques for the Characterization of Porous and Face Mask Membranes

“…The intrusion/extrusion technique for pore size characterization on membrane media operates in similar way as the well-known mercury porometry (HgP) technique and, consequently, it is also among the characterization methods that are also based on the Young-Laplace equation [15][16][17][18][19]. The HgP technique relies on the fact that, in this case, it is mercury (i.e., a non-wetting liquid) that is forced to enter the pores measuring the intruded volume (more specifically, the differential increment of specific volume) versus applied pressure.…”

Evaluation of pore size distribution via fluid-fluid displacement porosimetry: The viscous bias

“…Fluid-fluid displacement porosimetry (FFDP) is a technique for characterizing the pore size distribution of a porous medium (Morison, 2008;Peinador et al, 2010;Calvo et al, 2015;Tanis-Kanbur et al, 2019). In particular, the method is commonly used for the characterization of thin porous media such as ultrafiltration and microfiltration membranes (see e.g.…”

“…In particular, the method is commonly used for the characterization of thin porous media such as ultrafiltration and microfiltration membranes (see e.g. Peinador et al, 2010;Calvo et al, 2015;Tanis--Kanbur et al, 2019), and is traditionally referred to as the Liquid-Liquid Displacement Porosimetry (LLDP) technique since the two fluids commonly used are liquids. However, the technique can be extended to Gas-Liquid Displacement Porosimetry (Islam et al, 2020;Peinador et al, 2020) and can be simply referred to as the FFDP technique.…”

Morphological, Electrical, and Chemical Characteristics of Poly(sodium 4-styrenesulfonate) Coated PVDF Ultrafiltration Membranes after Plasma Treatment

“…Liquid–liquid displacement porosimetry (LLDP) is a very precise technique to elucidate pore radii, pore density, and molecular weight cut-off. Calvo et al [12,13,14] compared the LLDP outcomes with those of computerized image analyses from scanning electron microscopy (SEM-CIA) for UF membranes, showing a fair degree of accordance between both these methods. They also evaluated the molecular weight cut off (MWCO) for these membranes from cumulative pore size distributions obtained by LLDP.…”