Poly(arylene ether sulfone) copolymers as binders for capacitive deionization activated carbon electrodes

A comparison of multicomponent electrosorption in capacitive deionization and membrane capacitive deionization

“…To summarize, a CDI cycle consists of two steps, ion adsorption and ion desorption. While CDI is only economic for relatively dilute solutions, it has low energy consumption as it removes ions from the electrolyte rather than separating water from the salty stream, such as in reverse osmosis and distillation (Asquith et al 2015, Liu et al 2015).…”

Electron beam-based fabrication of crosslinked hydrophilic carbon electrodes and their application for capacitive deionization

“…This is probably due to the swelling phenomenon of the non-crosslinked SPVA binder in the carbon electrodes in the aqueous solution (which reduces the electrical conductivity of the electrodes) as previously reported in the literature. 28,32 On the other hand, the specic capacitances of the irradiated SPVA-based carbon electrodes increased with increase in the absorbed dose, and 10-SPVA-200 at the higher absorbed dose exhibited higher capacity (127 F g À1 ), corresponding to 67% improvement in comparison to that of 10-PVDF-0. At the same absorbed dose of 200 kGy, the 5-SPVA-200 electrode (containing more of the activated carbon) showed improved specic capacitance of 160 F g À1 .…”

“…3, the conventional 10-PVDF-0 exhibited the averaged contact angle of 83 , probably due to the presence of the hydrophobic PVDF binder. 28 On the other hand, all the samples prepared using SPVA binder with the same composition as the PVDF-based carbon electrode (10-SPVA-0, 10-SPVA-50, 10-SPVA-100, and 10-SPVA-200) showed contact angles of 0 regardless of the absorbed dose. 20 This result indicates that the newly developed SPVA binder (unlike with PVDF) allows the carbon electrodes to be very hydrophilic at the same composition, and that the hydrophilicity of the electrodes is not affected by electron beam irradiation.…”

“…6), the equivalent series resistance of 10-SPVA-0 (8.6 U) (taken as the frequency intercept on the real axis corresponding to the contact resistance) is higher than that of the conventional 10-PVDF-0 (7.7 U), verifying that reduction in the electrical conductivity of the carbon electrode was caused by the swelling phenomenon of the SPVA binder in aqueous solution, unlike the case with hydrophobic PVDF binder. 28 On the other hand, unlike the non-irradiated one, the electrical conductivity of the irradiated SPVA-based carbon electrodes had the tendency to increase with increasing absorbed dose. The 10-SPVA-200 electrode exhibited the lowest equivalent series resistance of 7.0 U, much lower than even the PVDF-based electrode with the same composition.…”

“…Unlike the conventional non-irradiated SPVA-based carbon electrode, the formation of a crosslinking network in the irradiated SPVA-based carbon electrodes allows the hydrophilic SPVA to transport ions efficiently into pores that are blocked in the hydrophobic PVDF-based system, without preventing the SPVA swelling-induced reduction in electrical conductivity, resulting in the improved capacitance. 28,32 The dose-dependent further improvement is probably due to enhancement of the electrical conductivity caused by the increased crosslinking density of the SPVA binders at the higher dose (leading to the more tightly bound activated carbons). 33,34 Furthermore, the activated carbon content-dependent improvement result could be ascribed to increment in the surface area and electrical conductivity facilitating the electrochemical processing.…”