0000000000481961
AUTHOR
Elizaveta Korzhova
Understanding the impact of poly(allylamine) plasma grafting on the filtration performances of a commercial polymeric membrane
Abstract Commercial membranes often exhibit difficulties in rejecting specific ionic species, and especially multivalent cations, due to their usual negative charge. To face this drawback, it is proposed here to functionalize the membrane surface by allylamine plasma polymerization. The impact of this modification on both permeation flux and ion rejection is investigated for single salt solutions and ion mixtures. It is shown that the membrane behaves like a positive membrane from the point of view of cation rejection but the negative charge (and the corresponding electrical field) inside pores leads to high rejection of divalent anions like a negative membrane. This allows a high selectivi…
Modification of commercial UF membranes by electrospray deposition of polymers for tailoring physicochemical properties and enhancing filtration performances
Abstract The main challenge for a widespread use of nanoporous membranes in the removal of ionic contaminants lies in the adjustment of their physicochemical properties to allow adequate ion rejection and mitigate fouling based on the targeted application. Most of the commercial membranes are negatively charged and their use is thus not necessarily relevant for divalent cation rejection. The main objective for researchers is therefore to provide novel tailored membranes by developing specific synthesis or modifying available membranes. It is proposed here to tailor physicochemical properties of a commercial low molecular weight cut-off ultrafiltration membrane by electrospray deposition of …
How Electrical Heterogeneity Parameters of Ion-Exchange Membrane Surface Affect the Mass Transfer and Water Splitting Rate in Electrodialysis
Electrodialysis (ED) has been demonstrated as an effective membrane method for desalination, concentration, and separation. Electroconvection (EC) is a phenomenon which can essentially increase the mass transfer rate and reduce the undesirable water splitting effect. Efforts by a number of researchers are ongoing to create conditions for developing EC, in particular, through the formation of electrical heterogeneity on the membrane surface. We attempt, for the first time, to optimize the parameters of surface electrical heterogeneity for ion-exchange membranes used in a laboratory ED cell. Thirteen different patterns on the surface of two Neosepta anion-exchange membranes, AMX and AMX-Sb, w…