Experiments to measure (i) the reactivity of lithium peroxide and lithium oxide in ambient air as a function of relative humidity and reactant particle size, (ii) the solubility of lithium hydroxide and lithium hydroxide monohydrate in three alcohols, namely methanol, ethanol and 1 and 2-propanol, as a function of time and temperature, (iii) the efficiency of the production of lithium peroxide in alcohol medium as a function of the concentration of LiOH.H 2O in methanol, the concentration of hydrogen peroxide, the kind of alcohol, the kind of feed material, and temperature and the time of mixing, (iv) the analysis of the precipitates, (v) the temperature of the precipitate decomposition in isothermal and non-isothermal conditions in ambient and neutral conditions as function of time, (vi) the activation energy of the precipitate decomposition, (vii) the temperature of the lithium peroxide decomposition in isothermal and non-isothermal conditions as function of time and (viii) the activation energy of lithium peroxide decomposition were performed. / The purpose of the study was to gather the data necessary to evaluate the production of lithium peroxide, Li2O2, and subsequently lithium oxide, Li2O, to be used as a feed for a silicothermic reduction process for the production of metallic lithium. The proposed basis for the production of Li2O2 was the conversion of lithium hydroxide or lithium hydroxide monohydrate by hydrogen peroxide in an alcohol medium. Alcohols were chosen because they are members of a class of non-aqueous solvents that can selectively dissolve the anticipated contaminants while precipitating the desired products. / It was found that the addition of hydrogen peroxide to alcohol solutions containing lithium hydroxide monohydrate resulted in the formation of lithium peroxide as lithium hydroperoxidate trihydrate with eight adduct molecules of methanol, i.e., Li2O2•H2O 2•3H2O•8CH3OH and involved the peroxide group transfer. The optimum conditions for the production of lithium peroxide were found to be (i) the least water concentration in the system (ii) the use of the temperature lower than ambient temperature and (iii) fast separation of the precipitate and raffinate to prevent dissociation of the precipitate or dissolving into the raffinate. / The high solubility of LiOH.H2O and at the same time the low solubility of Li2CO3 and of Li2O2 in methanol resulted in selection of methanol as the best alcohol of those studied for the proposed method of Li2O2 production. It also yielded high purity lithium peroxide. The production of Li2O 2 using H2O2 (35 %wt) required an excess of hydrogen peroxide equal to 2.6 times the stoichiometric amount. / The thermal decomposition of the lithium hydroperoxidate trihydrate precipitate started with the rejection of the adduct methanol molecules, followed by co-evolution of H2O and H2O2 from the resulting Li 2O2•H2O2•H2O. The activation energy of the decomposition reaction of the precipitate was measured as 141 kJ/mol. At temperatures greater than 200°C, lithium peroxide was found to be very reactive with atmospheric air. However, in an argon atmosphere, it rapidly decomposed losing the majority of the oxygen atoms, followed by the gradual slow diffusion of oxygen gas absorbed on the lithium oxide.

No description available.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Thèse de doctorat : Physique : Metz : 2007. / Thèse soutenue sur ensemble de travaux. Bibliogr. f. 32, [54], 67, 87, 140-141.

No description available.

This research investigated the effects of different doses of lithium on rats' behavior in an attempt to understand lithium's therapeutic mechanism of action in major affective disorders. / Although high doses (1.50 mEq/kg LiCl) decreased rats' open field activity, low doses (0.15 mEq/kg LiCl) increased activity, which is a new finding. A study of the effects of these two doses on reaction to environmental complexity and novelty suggested that, irrespective of dose, lithium increases readiness to engage in inspective exploration of a novel environment and promotes longer inspective exploration of a known complex environment. This was interpreted as increased selective attention to stimuli providing relevant information about the environment. The prediction derived from these findings, that both doses would decrease distractability, was supported in an experiment on tone-induced suppression of licking. / A two factor (activity, selective attention) model of lithium's action was proposed and its relevance to lithium's clinical efficacy in major affective disorders was discussed.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1972. / Bibliography: leaves 213-218. / xiv, 218 l illus., tables

Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 1993. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1962. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes Bibliographical references (leaves 49-51).