Adsorption of uranyl(II) into modified lamellar Na-Kanemite

Abstract

The Na-Kanemite sample was used for organofunctionalization process with N-propyldiethylenetrimethoxysilane and 3-aminopropyltriethoxysilane, after expanding the interlayer distance with polar organic solvents such as dimethyl sulfoxide (DMSO). The new organofunctionalized matrix was characterized by carbon nuclear magnetic resonance in the solid state SEM and chemical analysis. The resulted material was submitted to the process of adsorption with uranyl(II) at pH 2.0 and 298±1K. The Langmuir adsorption isotherm model has been to fit the experimental data with regression non-linear; the net thermal effects obtained from calorimetric titration measurements were adjusted to a modified Langmuir equation. The adsorption process was exothermic (ΔH=−7.14 to −5.98kJmol−1) accompanied by an increase in entropy (ΔS=52.28–62.12JK−1mol−1) and Gibbs energy (ΔG=−22.62 to −24.44kJmol−1). The favorable values corroborate with the uranyl(II)/basic reactive centres interaction at the solid/liquid interface in the spontaneous process for the new nanomaterials.