Table 1. Membranes Used in This Work.

sample code	ϕv	IECa (mmol g–1)	SLb (%)	WUc (%)
S-SESA	0	1.16 ± 0.02	46.5 ± 0.8	52.4 ± 3.6
S-SESB	0.2	1.40 ± 0.04	57.2 ± 1.9	109.2 ± 7.5
S-SESC	0.4	1.40 ± 0.01	57.1 ± 0.1	154.0 ± 6.2

^aIon exchange capacity (IEC), defined as the milliequivalents of sulfonic acid groups per dry gram of membrane (mmol g^–1).

^bSulfonation level (SL) is equal to the mole fraction of sulfonated styrene monomers over the total styrene (sulfonated + unsulfonated) monomers.

^cWater uptake, WU, of the membranes is defined by eq 1.