Studies on the hydrolysis of aqueous solutions of aluminum perchlorate and formation of gibbsite

• Main Authors: Wang, Shan-Li, 王尚禮
• Other Authors: Wang, Ming-Kuang
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/83728481192954616561

碩士 === 國立臺灣大學 === 農業化學系 === 81 === The ferron-colorimetric kinetics method, sulfate precipitates, transmission and scanning electronic mocroscopies, x-ray diffraction, Al-27 solution and solid state nuclear magnetic resonance analysis were employed to study the speciations in aluminum hydrolytic solutions. The Al polycations or polymers present in these solutions were characterized. These polymeric species precipitated by sulfate anion were present in the shapes of sphere, lath and irregular morphologies. The tetrahedron coordinated Al structure in the lath-shape particles was identified by Al-27 solid state NMR. The Al hydrolytic solutions were synthesized and aged at 25 C and 70 C. Distribution of the Al polymeric species in these solutions were shown the variation at different temperatures. Samples synthesized under higher temperature had lower degree of hydrolysis and had a longer induction period on formation of gibbsite. For the duration of aging at room temperature, formation of gibbsite was caused by the decomposition of the polymeric Al species to monomeric Al or low OH-Al polymers and conversion to gibbsite.