摘要

Natural montmorillonite (M) and synthetic kanemite (K) have been functionalized with 1,4-bis(3-aminopropyl)piperazine reacted with methylacrylate to yield new inorganic-organic chelating materials. The original and modified materials were characterized by X-ray diffractometry, textural analysis, SEM and nuclear magnetic nuclei of carbon-13 and silicon-29. The chemically modified clay samples (M-APPMA and K-APPMA) showed modification of its physical-chemical properties including: specific area 45.0 m(2) g(-1) (M) to 978.8 m(2) g(-1) (M-APPMA) and 23.5 m(2) g(-1) (K) to 898.9 m(2) g(-1) (K-APPMA). The ability of these materials to remove thorium(IV), uranyl(VI) and europium(III) from aqueous solution was followed by a series of adsorption isotherms, which were fitted to non-linear Sips adsorption isotherm model. To achieve the best adsorption conditions the influence of pH and variation of metal concentration were investigated. The energetic effects (Delta(int)H degrees, Delta(int)G degrees and Delta(int)S degrees) caused by metal ions adsorption were determined through calorimetric titrations.

  • 出版日期2009-11-15