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Abstract  

The precipitation behaviour of basic plutonium(IV) compounds from dilute nitric acid medium with aliphatic dicarboxylic acids has been investigated. Unlike plutonium(IV) oxalate, which is precipitated in acid medium (1–4M), the higher dicarboxylates precipitate in 0.9–2.5 pH range and their elemental analysis indicate Pu/dicarboxylate ratio of 11. The mode of formation, composition, solubility and thermal degradation behaviour for plutonium(IV) hydroxosuccinate has been studied. The hydroxy group determination by kinetic titration using fluoride complexing revealed that the compound has a Pu:OH ratio of 11 and determination of bridging oxygen group gave a Pu:O ratio of 10.5 suggest its formation as hydroxysuccinate having an oxobridged formula.

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Abstract  

The study was undertaken to evaluate the feasibility of functionalized multi-walled carbon nanotubes (MWCNTs) for the removal of UO2 2+ from aqueous solutions. The MWCNTs was treated by oxygen plasma and characterized by FTIR and XPS. The characterization indicates that MWCNTs is successfully functionalized of oxygen groups such as –COOH on its surface (denote as P-MWCNTs). The sorption of UO2 2+ from aqueous solution on P-MWCNTs was studied as a function of contact time, solid contents, pH, ionic strength and temperature under ambient conditions using batch experiment. Two simplified kinetic models of pseudo-first-order and pseudo-second-order were tested to determine kinetic parameters such as rate constants, equilibrium sorption capacities and related correlation coefficients for kinetic models of the sorption process. It can be seen that the UO2 2+ sorption on P-MWCNTs could be described more favorably by the pseudo-second-order model. The thermodynamic parameters (∆G°, ∆S°, ∆H°) calculated from the temperature-dependent sorption isotherms indicated that the sorption of UO2 2+ on P-MWCNTs were an endothermic and spontaneous processes. The results of the present study suggest that P-MWCNTs can be used beneficially in treating industrial effluents containing radioactive and heavy metal ions.

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Introduction Organic peroxides (OPs) are renowned for their thermal instability that lies in the specificity of the oxygen–oxygen group linkage, which is recognized for its relatively weak bonding dissociation energy (80–200 kJ

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other hand, the pesticide 2,4- d presents oxygen groups from carboxylic acid function, whereas other pesticides must interact by basic nitrogen groups. Indeed, the obtained data suggest that the silanol groups of magadiite must have a preference for

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[ 27 ]. The importance of oxygen functional groups on the carbon surface was discovered. Several studies have focused on the influence of surface oxygen groups upon the metal dispersion and catalytic performance [ 28 – 30 ]. The adsorption capacity of

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Journal of Thermal Analysis and Calorimetry
Authors: B. Marongiu, Silvia Porcedda, D. Falconieri, Alessandra Piras, E. Matteoli, and L. Lepori

and CH 2 groups in acids and dibutylether), type x, carboxylic group (COOH in acids) and type e, oxygen group in dibutylether. The equations used to calculate G E and H E in terms of DISQUAC are the same as in other applications [ 1 , 2 ] and are

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activity (14, 18, and 19 mm) against C. albicans , F. solani , and M. canis . The result reveals that antimicrobial activity these polyesters are due to the presence of nitrogen and oxygen groups. It has been suggested that the compound with N

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