Artículos (Física de la Materia Condensada)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/10869

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By-products revaluation in the production of design micaceous materials
(Elsevier Ltd, 2021) Mouchet, Anais; Raffin, Florian; Cota Reguero, Agustín; Osuna Barroso, Francisco Javier; Pavón González, Esperanza; Alba Carranza, María Dolores; Universidad de Sevilla. Departamento de Física de la Materia Condensada; Agencia Estatal de Investigación. España
One of the main objectives of a sustainable development and circular economy is the recycling of by-products generated in industrial and agricultural production processes. One of the possible solution is the use of such by-product materials in the synthesis of environmental adsorbents. In the current research, we present the synthesis of a high charge swelling mica with enhance adsorbent properties from blast furnace slag and rice husk ash. Moreover, to ensure the sustainable synthesis a natural bentoniteis used as Si and Al source. Thus, the current study investigated the fabrication of swelling high charged micas, Na-Mn (n (layer charge) = 2 or 4), from FEBEX bentonite, blast furnace slag and rice husk ash thorough the NaCl melt method. The reaction yield, cation framework distribution and structural characteristic of micas have been studied thorough X-ray Diffraction and Solid State Nuclear Magnetic Resonance. The yields of Na-Mn synthesis and degree of purity of the mica depends on the nature of these precursors. Thus, a sustainable, non-expensive and environmental friendly process has been evaluated.
Cesium adsorption isotherm on swelling high-charged micas from aqueous solutions: Effect of temperature
(Mineralogical Society of America, 2018) Osuna Barroso, Francisco Javier; Cota Reguero, Agustín; Pavón González, Esperanza; Pazos Zarama, Mery Carolina; Alba Carranza, María Dolores; Universidad de Sevilla. Departamento de Física de la Materia Condensada; Junta de Andalucía; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Programa Estatal Español de I+D+i orientado a retos sociales.; Empresa Nacional de Residuos Radiactivos (ENRESA). España
The potential use of a new family of synthetic swelling micas for cesium immobilization from aqueous solution was evaluated and the structural modifications after adsorption were analyzed. The results have revealed that they are good cesium adsorbents compared to natural clays and as the layer charge increases, the adsorption capacity and affinity increase. The cesium ions are adsorbed through a cation exchange mechanism, but an inner sphere complex with the basal O atoms of the tetrahedral sheet is favored. These findings imply that is possible to design minerals with improved environmental applications.
Heteroatom framework distribution and layer charge of sodium Taeniolite
(Elsevier, 2018) Perdigón Aller, Ana Carmen; Pesquera, Carmen; Cota Reguero, Agustín; Osuna, Francisco J.; Pavón González, Esperanza; Alba Carranza, María Dolores; Universidad de Sevilla. Departamento de Física de la Materia Condensada; Junta de Andalucía; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Gobierno de España; ENRESA
The most advanced applications of clays depend crucially on their hydration state and swelling is probably the most important feature of expandable 2:1 layered silicate. Sodium Taeniolite, Na-TAE, a swelling trioctahedral fluormica, has been synthesized and studied using thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and infrared and solid state NMR spectroscopies. The results indicated the formation of a swelling 2:1 phyllosilicate with actual layer charge lower than the nominal one. Herein, a new heteroatom distribution and more accurate composition could be deduced.
Hydration properties of synthetic high-charge micas saturated with different cations: An experimental approach
(Walter de Gruyter, 2013) Pavón González, Esperanza; Castro Arroyo, Miguel Ángel; Naranjo, Moisés; Orta Cuevas, María del Mar; Pazos, M. Carolina; Alba Carranza, María Dolores; Universidad de Sevilla. Departamento de Química Inorgánica; Universidad de Sevilla. Departamento de Física de la Materia Condensada; Universidad de Sevilla. Departamento de Química Analítica; Dirección General de Investigación Científica y Técnica (DGICYT). España
An understanding of the interaction mechanisms between exchangeable cations and layered silicates is of interest from both a basic and an applied point of view. Among 2:1 phyllosilicates, a new family of swelling high-charge synthetic micas has been shown to be potentially useful as decontaminant. However, the location of the interlayer cations, their acidity and the water structure in the interlayer space of these silicates are still unknown. The aim of this paper was therefore to study the hydration state of the interlayer cations in the interlayer space of high-charge expandable micas and to evaluate the effect that this hydration has on the swelling and acidity behavior of these new materials. To achieve these objectives, three synthetic micas with different charge density total layer charges (ranging between 2 and 4 per unit cell) and with five interlayer cations (Na+, Li+, K+, Mg2+, and Al3+) were synthesized and their hydration state, interlayer space, and acidity analyzed by DTA/TG, XRD, and 1H MAS NMR spectroscopy. The results showed that the hydration state depends on both the layer charge and the nature of the interlayer cation. A high participation of the inner-sphere complexes in the highly charged confined space has been inferred and proposed to induce Brønsted acidity in the solid.
Swelling layered minerals applications: A solid state NMR overview
(Elsevier, 2021) Pavón González, Esperanza; Alba Carranza, María Dolores; Universidad de Sevilla. Departamento de Física de la Materia Condensada
Swelling layered clay minerals form an important sub-group of the phyllosilicate family. They are characterized by their ability to expand or contract in the presence or absence of water. This property makes them useful for a variety of applications, ranging from environmental technologies to heterogeneous catalysis, and including pharmaceutical and industrial applications. Solid State Nuclear Magnetic Resonance (SS-NMR) has been extensively applied in the characterization of these materials, providing useful information on their dynamics and structure that is inaccessible using other characterization methods such as X-ray diffraction. In this review, we present the key contributions of SS-NMR to the understanding of the mechanisms that govern some of the main applications associated to swelling clay minerals. The article is divided in two parts. The first part presents SS-NMR conventional applications to layered clay minerals, while the second part comprises an in-depth review of the information that SS-NMR can provide about the different properties of swelling layered clay minerals.
Zirconium retention for minimizing environmental risk: Role of counterion and clay mineral
(Elsevier, 2021-03) Montes Montañez, Laura; Pavón González, Esperanza; Cota Reguero, Agustín; Alba Carranza, María Dolores; Universidad de Sevilla. Departamento de Física de la Materia Condensada
Zr(IV) together with U(IV) are the major components of high-level radionuclide waste (HLRW) and spent nuclear fuel (SNF) from nuclear power plants. Thus, their retention in the waste disposal is of great importance for the environmental risk control. Here, the influence of clay minerals on the retention of Zr(IV), as component of the nuclear waste and as chemical analogues of U(IV), has been evaluated. Three clay minerals, two bentonites and one saponite, were hydrothermally treated with three zirconium salts. A structural study at long-range order by X-ray diffraction and short-range order by NMR was performed to evaluate the generation of new zirconium phases and degradation of the clay minerals. Three immobilization mechanisms were observed: i) cation exchange of ZrO2+ or Zr4+ by clay minerals, ii) the precipitation/crystallization of ZrO2, and, iii) the chemical interaction of zirconium with the clay minerals, with the formation of zirconium silicates.

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Examinando Artículos (Física de la Materia Condensada) por Autor "Alba Carranza, María Dolores"