| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 98 === AZ91 machined scraps of the appearance of fine flake crumbs, so have the advantages of large specific surface area. AZ91 scraps would be immersed in 50˚C carbonate aqueous solution, continuously stirring 3h, the GAXRD analysis showed the surface of scraps had grown Mg,Al hydrotalcite film with intercalated carbonate ions. The Mg,Al hydrotalcite scraps were calcined at 450˚C, then absorbed chlorine and fluorine ions in aqueous solution respectively. The Al,Li hydrotalcite in-situ grown on Mg,Al hydrotalcite scraps, that could directly absorbed fluorine ions. The Mg,Al hydrotalcite scraps were immersed in the acid 3.5 wt. % NaCl aqueous solution, its intercalated ion become chlorine ion, then named Mg,Al(Cl-) hydrotalcite. In the experiment of absorption of fluorine ion, three kinds of treatment of hydrotalcite scraps which Mg,Al(Cl-) hydrotalcite scraps absorption capacity of the best, and 3.7 times of Al,Li/Mg,Al hydrotalcite scraps, and slightly better than the calcined Mg,Al hydrotalcite scraps. The Mg,Al hydrotalcite scraps continuously stirred in aqueous solution, due to the hydrotalcite film disintegration could be obtained powders, all of the powders had the composition of Mg,Al hydrotalcite structure through XRD analysis measured. By field emission scanning electron microscope, the powder showed the shape of hydrotalcite, but the powder by longer stirring, that hydrotalcite flake becomes smaller. The FTIR analysis of all powder showed that interlayer carbonate ions located at low symmetry C2v location. The FTIR results revealed the main structure of the powder was Mg3Al hydrotalcite between initial and intermediate stirring stage, in this stage the original hydrotalcite film disintegrated then made. At the post stage main structure of the powder was Mg2Al hydrotalcite that created by continuously generated the new film via stirring process.
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