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Abstract: The electric conductance of solutions of sulfuric, oxalic, benzoic, and salicylic acid (up to 0.02M) in dioxane–water mixed solvents (90% and 93% dioxane by mass) has been studied in the presence and absence of TiO2 and Al2O3 (0.5–5% by mass). TiO2 and Al2O3 enhanced the conductance of solutions of organic acids in aqueous dioxane. The conductance is interpreted in terms of adsorption of acid in molecular form, dissolution of ceramic oxides in form of anionic complexes, and leaching of acidic impurities from ceramic oxides. [Copyright &y& Elsevier]

Abstract: Cationic corn starch derivatives with a high degree of substitution are prepared in alkaline solution or in mixed media of organic solvent and water with different levels of the cationic reagent, 2,3-epoxypropyltrimethylammonium chloride. The starch cationization yield is investigated, and the results indicate that the degree of substitution (DS) of the samples depends on the reaction conditions and reaction media. The maximum DS values are up to 1.37 in 1,4-dioxane alkaline–aqueous solution. Meanwhile, the structures of the cationic starch derivatives are characterized by elemental analyses, FTIR spectroscopy, X-ray diffraction, and 13C NMR spectroscopy, as well as by SEM techniques. [Copyright &y& Elsevier]