Publications by authors named "Meghna Dilip"

Highly charged metal ions are difficult to investigate in weakly coordinating ionic liquids (ILs) because of the insolubility of their solid forms, but the molecular liquid TiCl offers a way to react tetravalent metal ions in an IL. Reactions of TiCl with 1-butyl-3-methylimidazolium ([Cmim])-based ILs containing chloride or bromide lead to mixtures of highly metastable amorphous solids and small amounts of crystalline chlorotitanate salts including [Cmim][TiCl] and two polymorphs of [Cmim][TiCl] in a manner not well correlated with stoichiometry or anion identity. The reaction of TiCl with [Cmim][BF] yields crystals of the mixed fluoro-chloro complex [Cmim][TiFCl], indicating spontaneous reaction of the IL ions to generate HF in situ.

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New, potentially green, and efficient synthetic routes for the remediation and/or re-use of perchlorate-based energetic materials have been developed. Four simple organic imidazolium- and phosphonium-based perchlorate salts/ionic liquids have been synthesized by simple, inexpensive, and nonhazardous methods, using ammonium perchlorate as the perchlorate source. By appropriate choice of the cation, perchlorate can be incorporated into an ionic liquid which serves as its own electrolyte for the electrochemical reduction of the perchlorate anion, allowing for the regeneration of the chloride-based parent ionic liquid.

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Variation in operational temperatures has revealed differences in the partitioning behavior of probe solutes between the phases in aqueous biphasic systems (ABS) and the related aqueous biphasic extraction chromatographic resin (ABEC). This difference has been studied using the hydrophobic anion, 99TcO4-, as a probe and (NH4)2SO4 as the kosmotropic salt. Distribution of the hydrophobic anion 99TcO4- to the PEG-rich phase in a MePEG-5000/(NH4)2SO4 ABS increases with increasing temperature, but decreases are observed in batch uptakes of this anion to ABEC resins from (NH4)2SO4 solutions.

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Aqueous biphasic systems (ABS) are useful for the extraction of dye molecules from aqueous solution. Thus, they can be used in textile dye bath effluent treatment. The partitioning behavior of two commercially used textile dyes-Cibacron Scarlet LS 2G and Astacryl Red 3B were investigated in a TBAB-salt aqueous biphasic systems.

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