Milli q plus reagent

All aqueous solutions were prepared using deionized and charcoal-treated water (>18.2 MΩ cm specific resistance) obtained with a Milli-Q PLUS reagent grade water system (Millipore, Bedford, MA). High molecular weight poly(vinyl chloride), 2-nitrophenyl octyl ether, tridodecylmethylammonium chloride, sodium 1-dodecyl sulfate (≥ 99%, by titration with benzethonium chloride), 1-octyl sulfate, and tetrahydrofuran (anhydrous; inhibitor-free) were purchased from Sigma-Aldrich (St. Louis, MO), poly(dimethylamine-co-epichlorohydrin) (MW = 240000; repeat unit MW = 137.6) from Accepta (Manchester, UK), and NaCl and Tygon S3 tubing (4.8 mm inner diameter; 7.9 mm outer diameter) from Fisher Scientific (Waltham, MA). All materials were used as received.

Aqueous solutions were prepared using deionized and charcoal-treated water (>18.2 MΩ cm specific resistance) obtained with a Milli-Q PLUS reagent grade water system (Millipore, Bedford, MA). AgCl (98%), KCl, Na2SO4, CaCl2, 1.0 M NaOH, and 1.0 M HCl were purchased from Sigma-Aldrich, Ag wires (0.5 mm diameter, ≥99.9%) from Alfa Aesar (Tewksbury, MA), and porous glass disks (15 mm diameter; 1.2 mm thick; 1.0 ± 0.1, 5.0 ± 0.5, 20 ± 2, 50 ± 5, and 100 ± 10 nm diameter pores) from Boraglas (Stuttgart, Germany). All chemicals were used as received.