Polysulfides measurement techniques

We have extended the technique of Relaxation Spectrum Analysis to cover the seven orders of magnitude of the experimentally available frequency range. This frequency range is required for a complete description of the equivalent circuit for our CdSe-polysulfide electrolyte cells. The fastest relaxing capacitive element is due to the fully ionized donor states. On the basis of their potential dependence exhibited in the cell data and their indicated absence in the preliminary measurements of the Au Schottky barriers on CdSe single crystals, the slower relaxing capacitive elements are tentatively associated with charge accumulation at the solid-liquid interface. 

All the other reaction products appear to be chain styrene polysulfides of different molecular weights. The two oligomers I and II have been obtained from the fraction VRE approx. 0.73, and fully characterized by elemental analysis, molecular weight measurement, and various spectroscopic techniques. 

Various polarographic techniques have been successfully used to measure elemental sulfur, S , and sulfide (H2S and HS ) concentrations in laboratory solutions [116], salt water [117], saline lake [118], freshwater [119], lake porewaters [120], salt marsh sediments [109,120], and marine porewaters [121], Using stripping square wave voltammetry, researchers have been able to measure sulfide species at nanomolar concentrations [118-120, 122,123], Recently, cyclic and linear sweep voltammetries have been used to quantify elemental sulfur S , hydrogenosulfide (HS ) and polysulfides (S ) with fast scan rates (IV s ) [124] for example, in estuarine sediments (from Rehoboth Bay, an inland bay located in Delaware), the sulfur speciation was found to change throughout a core profile, with dominant in the top layers (0-6 cm), dominant... 

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