Chemisorption of lanthanide ions on succinate-functionalized mesoporous silica: An in situ characterization by fluorescence

LOMBARDO, M. VERÓNICA; MIRENDA, MARTÍN; BORDONI, ANDREA V.; WOLOSIUK, ALEJANDRO; REGAZZONI, ALBERTO E.

JOURNAL OF COLLOID AND INTERFACE SCIENCE

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2017 vol. 507 p. 139 - 144

0021-9797

Chemisorptionof Eu3+ and Tb3+ on SBA-15 functionalized with succinicgroups has been studied by in situsteady-statefluorescence measurements. The enhancement of the emission sensitive bandsindicates that both ions adsorb forming inner-sphere surface complexes.Adsorption is a fast process that attains equilibrium in about 5 min. Thevariation of the peaks maxima (I592and I616, for europium,and I490 and I545, for terbium) with thetotal ion concentration is accountedfor by the sum of the contributions due tothe adsorbed and free ions. The formercontribution islangmuirian. At pH 4.5,the respective adsorption constants are 5´ 105and 3 ´ 105 M-1,and the maximum adsorption capacities are5.10´ 10-4 and 5.23´ 10-4mol g−1. The mismatch between the lattervalues and the number of attached carboxylic groups is discussed. Comparisonwith other functionalized mesoporoussilicas indicates that the anchoredsuccinic groups are very efficient for removing lanthanide ions from aqueoussolutions.