TY - JOUR AU - Kovács, Eszter Mária AU - Baradács, Eszter AU - Kónya, Péter AU - Kovács-Pálffy, P AU - Harangi, Sándor AU - Kuzmann, Ernő AU - Kónya, József AU - M. Nagy, Noémi TI - Preparation and structure's analyses of lanthanide (Ln) -exchanged bentonites JF - COLLOIDS AND SURFACES A : PHYSICOCHEMICAL AND ENGINEERING ASPECTS J2 - COLLOID SURFACE A VL - 522 PY - 2017 SP - 287 EP - 294 PG - 8 SN - 0927-7757 DO - 10.1016/j.colsurfa.2017.02.085 UR - https://m2.mtmt.hu/api/publication/3208553 ID - 3208553 N1 - Funding Agency and Grant Number: EUEuropean Union (EU); European Regional DevelopmentEuropean Union (EU) [GINOP-2.3.2-15-2016-00008]; Hungarian National Research, Development, and Innovation Office [NKFIH K 120265] Funding text: This work was supported by the EU and co-financed by the European Regional Development [GINOP-2.3.2-15-2016-00008]; the Hungarian National Research, Development, and Innovation Office [NKFIH K 120265]. Imre Lajos Isotope Laboratory, Department of Colloid and Environmental Chemistry, University of Debrecen, 4032 Egyetem tér 1., Debrecen, Hungary Department of Solid State Physics, University of Debrecen, 4026 Bem tér 18/b, Debrecen, Hungary Geological and Geophysical Institute of HungaryH-1143, Hungary Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, H-4032, Hungary Institute of Chemistry, Eötvös Loránd University, 1117, Budapest, Hungary Cited By :8 Export Date: 5 February 2021 CODEN: CPEAE Correspondence Address: Nagy, N.M.; Imre Lajos Isotope Laboratory, 4032 Egyetem tér 1., Hungary; email: nagy.noemi@science.unideb.hu AB - The interaction between Lanthanides (Ln)- ions and Ca-bentonite and the structural changes accompanying were studied. Ln-exchanged bentonites were prepared from Ca-bentonite (Istenmezeje, Hungary) by ion exchange in three consecutive washings with lanthanide solutions. Scanning Eletronmicroscopy Energy Dispersive X-ray spectroscopy (SEM-EDX) studies showed even distribution of Lns and other components of bentonite. The natural bentonite and the lanthnide exchanged bentonites were characterized by X-ray diffraction (XRD), which revealed the same mineral composition, and the increase of the basal spacing of montmorillonite from 1.465 (Ca2+) to 1.577 nm (REE3+). The d001 basal spacing of lanthanide montmorillonite increases as the ion radius of the lanthanide cation increases. The Fe3+, and Lns3+ amount on the bentonite were determined by X-ray-fluorescence spectrometry (XRF) elemental analysis. The amount of exchanged Lns were determined by washing the Ln-bentonite with 1 M ammonium-acetate, and measuring the amount of Ln released, using inductively coupled plasma optical emission spectrometry (ICP-OES). In most Ln-bentonites, the quantity of the exchanged Ln ions was about 80–90% of the cation exchange capacity (CEC) of the bentonite. In case of some lanthanides bentonite (La3+, Ce3+, and Gd3+), however, the sorbed quantity of lanthanum ions was higher than the cation exchange capacity. In case of lanthanum-bentonite, the lanthanide quantity is as high as 136% of CEC. Moreover, the iron(III) content of lanthanum bentonite is less than that of the original Ca-bentonite. Mössbauer spectra of the La-, Ce-, and Gd-exchanged samples at 78 K revealed an unexpected magnetically split component that was absent from the Ca-bentonite. This component may belong to interlayer Fe. This iron can be released from the octahedral positions crystal lattice. © 2017 Elsevier B.V. LA - English DB - MTMT ER -