TY - JOUR
T1 - Sulfonated polyethersulfone based cation exchange membranes for reverse electrodialysis under high salinity gradients
AU - Avci, Ahmet H.
AU - Rijnaarts, Timon
AU - Fontananova, Enrica
AU - Di Profio, Gianluca
AU - Vankelecom, Ivo F.V.
AU - de Vos, Wiebe M.
AU - Curcio, Efrem
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Salinity Gradient Power - Reverse Electrodialysis (SGP-RED) is a promising membrane-based technology to harvest the energy of mixing from solutions of different ionic concentration. Unfortunately, currently available commercial ion exchange membranes – being not specifically designed for RED – are far from satisfying the requirements of this operation, especially when operated with hyper-concentrated brines. In this work, novel sulfonated polyethersulfone (sPES) cation exchange membranes (CEM) were prepared by phase inversion method and tested under high salinity gradients. Use of 5 M NaCl electrolyte for immersion precipitation coagulation bath facilitated the self-standing membrane formation as a result of the electrostatic interaction between the fixed charged groups and electrolyte solution. Microscopy results revealed that dense or asymmetric membranes with non-connected pores were formed by solvent evaporation or immersion precipitation, respectively. The membranes were characterized for ion exchange capacity, water uptake, charge density and thickness, and further studied by electrochemical impedance spectroscopy. The obtained properties of the newly developed membranes were subsequently compared to those of commercial CMX (Neosepta, Japan) and Fuji-CEM-Type 1 (Fujifilm, The Netherlands) membranes. The asymmetric membranes resulted in a very low resistance especially for high ionic gradients but relatively low permselectivity, while dense membranes still had a low resistance compared to commercial membranes and exhibited high permselectivity. Interestingly, in terms of power density, lab-made membranes outperformed the commercial benchmarks when tested for RED applications with brackish water (0.1 M NaCl)/hypersaline brine (4 M NaCl) feeds; power density of CMX and Fuji-CEM-Type 1 were 3.23 and 3.77 W/m2, respectively, while power density of asymmetric and dense sPES membranes were 3.64 and 3.92 W/m2, respectively.
AB - Salinity Gradient Power - Reverse Electrodialysis (SGP-RED) is a promising membrane-based technology to harvest the energy of mixing from solutions of different ionic concentration. Unfortunately, currently available commercial ion exchange membranes – being not specifically designed for RED – are far from satisfying the requirements of this operation, especially when operated with hyper-concentrated brines. In this work, novel sulfonated polyethersulfone (sPES) cation exchange membranes (CEM) were prepared by phase inversion method and tested under high salinity gradients. Use of 5 M NaCl electrolyte for immersion precipitation coagulation bath facilitated the self-standing membrane formation as a result of the electrostatic interaction between the fixed charged groups and electrolyte solution. Microscopy results revealed that dense or asymmetric membranes with non-connected pores were formed by solvent evaporation or immersion precipitation, respectively. The membranes were characterized for ion exchange capacity, water uptake, charge density and thickness, and further studied by electrochemical impedance spectroscopy. The obtained properties of the newly developed membranes were subsequently compared to those of commercial CMX (Neosepta, Japan) and Fuji-CEM-Type 1 (Fujifilm, The Netherlands) membranes. The asymmetric membranes resulted in a very low resistance especially for high ionic gradients but relatively low permselectivity, while dense membranes still had a low resistance compared to commercial membranes and exhibited high permselectivity. Interestingly, in terms of power density, lab-made membranes outperformed the commercial benchmarks when tested for RED applications with brackish water (0.1 M NaCl)/hypersaline brine (4 M NaCl) feeds; power density of CMX and Fuji-CEM-Type 1 were 3.23 and 3.77 W/m2, respectively, while power density of asymmetric and dense sPES membranes were 3.64 and 3.92 W/m2, respectively.
KW - Cation exchange membrane
KW - Electrochemical impedance spectroscopy
KW - Reverse electrodialysis
KW - Salinity gradient power
KW - Sulfonated polyethersulfone
KW - 22/2 OA procedure
U2 - 10.1016/j.memsci.2019.117585
DO - 10.1016/j.memsci.2019.117585
M3 - Article
AN - SCOPUS:85074338976
SN - 0376-7388
VL - 595
JO - Journal of membrane science
JF - Journal of membrane science
M1 - 117585
ER -