@article{MTMT:3208553,
	title = {Preparation and structure's analyses of lanthanide (Ln) -exchanged bentonites},
	url = {https://m2.mtmt.hu/api/publication/3208553},
	author = {Kovács, Eszter Mária and Baradács, Eszter and Kónya, Péter and Kovács-Pálffy, P and Harangi, Sándor and Kuzmann, Ernő and Kónya, József and M. Nagy, Noémi},
	doi = {10.1016/j.colsurfa.2017.02.085},
	journal-iso = {COLLOID SURFACE A},
	journal = {COLLOIDS AND SURFACES A : PHYSICOCHEMICAL AND ENGINEERING ASPECTS},
	volume = {522},
	unique-id = {3208553},
	issn = {0927-7757},
	abstract = {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.},
	keywords = {WATER; X-ray diffraction; scanning electron microscopy; MONTMORILLONITE; TURKEY; CENTRAL ANATOLIA; CLAY-MINERALS; kaolinite; sorption; Earth; GENESIS; Inductively coupled plasma optical emission spectrometry; X-ray-fluorescence spectrometry; Complexometric titration; Ln-bentonites},
	year = {2017},
	eissn = {1873-4359},
	pages = {287-294},
	orcid-numbers = {Kovács, Eszter Mária/0000-0002-3117-2521; Kuzmann, Ernő/0000-0002-0183-6649}
}