Influence of temperature and time on the Eu 3+ reaction with synthetic Na-Mica- n ( n = 2 and 4)

Eu3+ Luminescence in High Charge Mica: An In Situ Probe for the Encapsulation of Radioactive Waste in Geological Repositories

“…X-ray diffraction measurements also showed new reflections that correspond to the incipient crystallization of secondary phases resulting from the mica disruption and from the interaction of Eu 3+ with the mica framework. 23 Considering different treatment times, it is worth noting that at 0 days and 300°C (these conditions imply a heated ramp up to 300°C of the system Mica-2/Eu(NO 3 ) 3 solution, followed by the cooling of the sample at room temperature), Eu 3+ adsorption occurs in slightly higher amounts compared to the cation exchange capacity of Mica-2, confirming that Eu…”

“…On the contrary, the sample treated at 300°C presents sharper line emission, which can be attributed to a transition to new crystalline phases, in particular europium disilicate, Eu 2 Si 2 O 7 , as well as europium aluminate, EuAlO 3 , with different Eu 3+ distribution within the host lattice, according to X-ray diffraction results, as it has been described elsewhere and introduced before (Figure 1). 23 Firstly, Figure 3 clearly shows that Eu 3+ green emission from the 5 D 1 excited state is only observed for the samples treated at 150 and 200°C. 5 D 1 luminescence is very sensitive to nonradiative relaxation processes caused by high phonon energy in the host material, crossrelaxation between Eu 3+ ions or charge transfer processes.…”

“…The effect of temperature and time on the retention of Eu 3+ by Mica-2 has been previously analyzed in detail by X-ray diffraction and presented elsewhere. 23 The major conclusions of the study are introduced below. Regarding temperature dependence, treatments at and 200°C for a month cause the incorporation of hydrated Eu 3+ cations to the interlayer space of the aluminosilicate along with some disruption of the silicate network.…”

Bionanocomposites based on chitosan intercalation in designed swelling high-charged micas

“…Moreover, their physical and chemical properties can be easily tuneable by an appropriate synthesis method 40–43 . These synthetic clay minerals have been successfully applied for the selective removal of heavy metals 40 , highly radioactive ions 44,45 and hydrocarbon molecules after an appropriate surface modification 46,47 . In fact, they overcome the limited CEC and adsorption capacity of natural nanoclays, and, in particular, organo-functionalized swelling high charged micas have already shown their excellent sorption capacity for the non-ionic organic pollutants benzene, toluene and phenol 47 .…”

Cesium adsorption isotherm on swelling high-charged micas from aqueous solutions: Effect of temperature

“…These micas have attracted considerable interest because of their exceptional adsorption capacity and selectivity of harmful cations (Alba et al 2006;Franklin and Lee 1996;Garcia-Jimenez et al 2016;Kodama et al 2001;Paulus et al 1992) and they constitute a promising material for Cs adsorption.…”