Poly(amidoamine) Dendrimer Functionalized Carbon Nanotube for Efficient Sorption of Trivalent f‐Elements: A Comparison Between 1st And 2nd Generation

Poly(amidoamine) dendrimer functionalized carbon nano tubes were synthesized, characterized and used for the sorption of americium from aqueous acidic waste solution. The sorption of Am3+ has been found to take place through pseudo second order kinetics with the rate constants of 8.61E‐05 and 5.38E‐05 mg g−1 min−1for 1st and 2nd generation, respectively, followingLangmuir isotherm. The MWCNT‐PAMAMG1 and MWCNT‐PAMAMG2 have high radiolytic stability. The stripping study revealed that EDTA can be effectively used for almost quantitative back extraction of metal ion from both generation of dendrimer. Luminescence investigation revealed the presence of single species with no inner sphere water molecule. The 1st generation dendrimer complex was found to be more asymmetric compared to the 2nd generation. The analysis of Judd Offelt parameters and evaluation of photo‐physical properties were carried out to understand the complexation of Am3+ with these sorbents. The adsorption for Am3+ were found to be higher for second generation dendrimer (MWCNT‐PAMAMG2) as compared to the first generation (MWCNT‐PAMAMG2) owing to the availability of higher number of binding sites in the former generation. The Sorption capacity of MWCNT‐PAMAMG2 (97.62 mg g−1) was found higher than that of MWCNT‐PAMAMG1 (82.59 mg g−1). The sorption process followed Langmuir isotherm and pseudo second order rate kinetics.