Thiosulfates

Abstract: We report the formation of self-assembled monolayers (SAMs) from sodium S-alkyl thiosulfates (CH3(CH2)n-1S2O3-Na+) onto copper in aqueous and organic solvents. These ionic compounds are considerably more soluble in water than alkanethiols, and they adsorb to the copper surface primarily as thiolates. Characterization by electrochemical impedance spectroscopy (EIS) reveals that SAMs formed from longer-chained thiosulfates (n = 12, 14) exhibit comparable barrier properties to those of thiol-based SAMs when formed in organic solvents but diminished effectiveness when formed in aqueous solution. However, the water-borne thiosulfate-based SAMs do provide an increase in corrosion resistance by ∼2−3 orders of magnitude compared to that of uncoated copper. Analysis by infrared (IR) spectroscopy indicates that the thiosulfate-based SAMs are less crystalline and less densely packed than thiol-based SAMs. Wetting measurements suggest that the surfaces of thiosulfate-based SAMs expose a greater number of methylene gr...

Abstract: A process for stabilizing in situ soluble mercury in deposits of mercury-containing materials which comprises treating the deposits with a stabilizing amount of an inorganic sulfur compound. Suitable inorganic sulfur compounds include sulfides, alkali metal thiosulfates, alkaline earth metal thiosulfates, iron thiosulfates, alkali metal dithionites, and alkaline earth metal dithionites. These inorganic sulfur compounds react with soluble mercury to convert it to insoluble mercury compounds and substantially inhibit its removal by elution with water from the deposits of mercury-containing material. The process may be used to treat land areas, landfill deposits, or submarine sediment deposits to reduce soluble mercury concentrations to a few parts per billion.