| dc.description.abstract | Nihonium is classified as a superheavy element and is only produced artificially through nuclear reaction in a particle accelerator. Its chemical properties are largely unknown and the chemical experiments involving nihonium are very challenging and require a system that is sustainably fast and reliable. The study of nihonium homologs, indium and thallium, was carried out to provide the basis for a suitable chemistry system that can potentially be used to study nihonium chemistry in the future. This homolog study focuses on developing a novel chemical procedure to extract and separate indium and thallium metals. These elements were extracted from hydrochloric acid media into imidazolium-, pyrrolidinium-, and betainium-based ionic liquids, as well as DL-menthol-based eutectic solvents, by using a liquid-liquid extraction (LLE) technique. Generally, it was found that the aqueous phase acidity affected the extraction yield and thus, the speciation of the metals. The extraction kinetics were found to be sufficiently fast as the reaction equilibrium was reached within one minute in all the systems that were studied. Thallium, which has two oxidation states: +1 and +3, was more effectively extracted when bromine water was used as the oxidizing agent, compared to chlorine water. Among all three metals that were studied, Tl(I) was only poorly extracted into either solvent that was tested. In(III) was best extracted into a betainium-based ionic liquid from a low HCl concentration with the presence of 15% betaine. In the case of Tl(III), the highest extraction yield was obtained in the system containing an imidazolium-based ionic liquid.
The length of the alkyl chain and the anion group of this ionic liquid affected Tl(III) extraction yield, but eventually the best extraction was obtained with an ionic liquid that has the most carbon atoms on its alkyl side. In an attempt to understand the metal extraction mechanism in a betainium-based ionic liquid, the mutual solubility between this ionic liquid and water was studied. The influence of hydrochloric acid and zwitterionic betaine were investigated. It was found that both acid and betaine increased the mutual solubility of the aqueous and the organic phases. In addition, zwitterionic betaine was found to be partially distributed between the two phases. | en |
