Polyallylammonium Ferrocyanide Films for Trace Water Detection in Halogenated Solvents

Abstract

Polyallylammonium films with electrostatically bound ferrocyanide were formed by electrochemically reducing ferricyanide ions in the presence of polyallylammonium chloride. These films could be deposited onto the surfaces of Pt, Au or SnO 2 electrodes. In anhydrous organic electrolyte solutions, these films are electroinactive but become electroactive after the addition of trace water. For concentrations of water from 0.0 to 0.12% in chlorinated solvents, the electroactivity is linear with water concentration. The linearity between concentration of water and electroactivity can be exploited to develop a subsaturation trace water sensor.

Pulsed Discharge Helium Ionization Detector for Highly Sensitive Aquametry

“…We used the direct injection of 0.2 μL of dried benzene containing various quantities of backadded water for these experiments, since water was reported to be a frequent contaminant of organic solvents. 23 The tests were also conducted in accordance with the five-point calibration recommended by the United States Environment Protection Agency (US-EPA) method. 24 Increasing concentrations of water spiked into benzene produced increasingly larger water peaks emerging from the GC column at ~96 s post-sample injection as detected by the PDHID-D2 (Fig.…”

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

“…Again, high temperatures for curing, such as above 200 C, should be avoided because of potential degradation of some active substances. In this regard, a small molecule, namely 1,3,5-tris (azidomethyl)benzene (TAMB), was prepared by Pötzsch and Voit [233] and successfully used to crosslink the hb-PPh matrix both thermally and photochemically. The mechanisms of these two crosslinking reactions were different; in thermal curing, triazole units were formed between the acetylene groups of hb-PPh and the azide group of the crosslinker in a 1,3-dipolar cycloaddition reaction.…”

“…Poly(diallyldimethylammonium chloride) (PDADMAC) and ferri-/ferrocyanide show a similar behavior [233]. In most cases, the ferri-/ferrocyanide (trivalent/ tetravalent hexacyanoferrate[III]/[II]) couple exhibits an unexpected interaction pattern with strong cationic polyelectrolytes.…”

“…The electroactivity in nonpolar solvent is then very dependent on the water content of the organic solvent, which allows the construction of a water sensor [233]. Polyelectrolyte brushes [450,451] attracted oppositely charged counterions such as ruthenium complexes or hexacyanoferrate to electrode interfaces [452][453][454][455][456], while the surface energy could be altered electrochemically (Fig.…”

Cathodic Stripping Determination of Water in Organic Solvents

“…Electrochemical method is an alternative choice due to its simplicity, low cost and fast response. Conductivity and impedance-based methods have been reported to determine trace water in organic solvents [23][24][25], which however are insensitive and require applying surface coatings to the electrodes and the addition of redox mediators to the solvent samples.…”