Person:
Astilleros García-Monge, José Manuel

First Name

José Manuel

Last Name

Astilleros García-Monge

URI

https://hdl.handle.net/20.500.14352/75202

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

Department

Mineralogía y Petrología

Area

Cristalografía y Mineralogía

Identifiers

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Now showing 1 - 10 of 22

Comment: supersaturation in binary solid solution-aqueous solution systems (Comment on “Crystallization kinetics in binary solid solution – aqueous solution systems” by Alexander G. Shtukenberg, Yurii O. Punin and Pavel Azimov, American Journal of Science, v. 306, p. 553–574.)
(American Journal of Science, 2007) Prieto Rubio, Manuel; Astilleros García-Monge, José Manuel; Pina Martínez, Carlos Manuel; Fernández Díaz, María Lourdes; Putnis, Andrew
Anglesite (PbSO4) epitactic overgrowths and substrate-induced twinning on anhydrite(CaSO4) cleavage surfaces
(Journal of Crystal Growth, 2013) Morales, Juan; Astilleros García-Monge, José Manuel; Fernández Díaz, María Lourdes; Álvarez-Lloret, Pedro; Jiménez, Amalia
The dissolution–precipitation reactions occurring on mineral surfaces are considered an effective means to remove high amounts of dissolved toxic metals from fluid phases by precipitation of an ewsolidin whose structures the pollutant is immobilized. However, for the sereactionstobeefficient acontinuous communication between the fluid and mineral phasesis required. This communication can be significantly hindered when the new solid phase forms a continuous, homogeneous layer on the mineral substrate. The formation of such a layer is more likely to occur when epitactic relationships exist between the newly for medphase and the mineral substrate. Dissolved lead can be removed by interaction of the Pb-bearing aqueous solution with anhydrite (CaSO4) leading to the formation of anglesite (PbSO4). Here, the relationship between anglesite crystals and ananhydrite substrate is investigated. The three main anhydrite cleavage surfaces, (100),(010), and (001) are considered. Ahigh density of riented anglesite crystals growing with their (210) plane parallel to the substrate was observed on (001) Anh. The density of oriented an glesite was, however, significantly lower on (100) Anh and almost negligible on (010) Anh. Anglesite grew with its (001) plane parallel to the substrate on (100) Anh, but no evident epitactic relationship was found with (010) Anh. Differences in anglesite crystal density are explaine don the ground sof structural similar ities and the goodness of anglesite–anhydrite matching through the interface. Both on anhydrite (100) and (001) anglesite crystals showat least two specific orientations, which relate to each other through symmetry operators presentin the substrate. The coalescence of differently oriented anglesite crystals leads to the formation of twins. This twinning phenomen on is designated as substrate-induced twinning, since the twinning lawis determined by the substrate symmetry. In the particular case of anglesite growing on anhydrite (100) two different orientations have been observed, related eacho ther through (210) Ang which actas twin plane.
In situ HAFM study of the thermal dehydration on gypsum (010) surfaces
(American Mineralogist, 2006) Jordan, Guntram; Astilleros García-Monge, José Manuel
Hydrothermal AFM has been used to study the thermal dehydration reaction on gypsum (010) surfaces in solutions at different saturation states, and in the absence of a bulk liquid phase. Experiments were carried out at temperatures ranging from 25 to 130 °C. Whereas supersaturated solutions (β = 1.8–5) caused gypsum growth in the entire temperature range, solutions close to equilibrium (β = 1.02) caused various responses of the gypsum surface. The most prominent was a sharp transition from fast growth to very fast dissolution at ∼120 °C suggesting a sudden nucleation of a phase more stable than gypsum. No structural relation could be found between the parental gypsum (010) surface and the crystallizing phase. In the absence of a bulk liquid phase, dehydration takes place via the nucleation and spreading of etch-pit like pattern. Laterally, the thermal etch pits spread in an unrestricted way. In the vertical direction, pit growth was limited to a few micrometers. Dehydration by monolayer pits and nucleation of the dehydration process at monolayer steps on the (010) surface were never observed. Thus, unlike growth or dissolution, surface energy related to kink sites or individual point defects seems to be insuffi cient to trigger dehydration. The temperature-dependent lateral pit growth yields an activation energy of 119 ± 11 kJ/mol. The product phase disintegrates at the parental surface into nano-size particles without any morphologically noticeable transition zone.
Geología de Grado en Química. Prácticas. 6. Simetría (III)
(Reduca. Geología, 2010) Astilleros García-Monge, José Manuel; López De Andrés, María Sol; Viedma Molero, Cristóbal; Vindel Catena, Elena
Los ejercicios que a continuación se proponen son, en cierta medida, similares a los ya realizados en la práctica 4. Básicamente la práctica consiste en identificar los elementos de simetría presentes en objetos que presentan simetría puntual (en este caso, modelos tallados en madera que representan distintos poliedros cristalinos). La principal diferencia con respecto a la citada práctica es la adición de una tercera dimensión, lo que añade un mayor grado de complejidad, puesto que: a) la existencia de de una tercera dimensión condiciona la aparición de nuevos elementos de simetría (ejes impropios) no existentes en el mundo bidimensional y b) para plasmar adecuadamente la simetría de un objeto tridimensional en un plano es fundamental realizar la proyección estereográfica de las caras que componen los citados poliedros, de tal manera que se preserven sus relaciones angulares. Además de proyectar las caras de 15 poliedros cristalinos y determinar sus elementos de simetría, el alumno deberá clasificarlos en alguno de los 32 grupos puntuales tridimensionales o las 32 clases de simetría. Por último el alumno deberá identificar de qué forma o formas cristalinas están constituidos dichos poliedros.
El empleo del AFM Hidrotermal (HAFM) en el estudio de la deshidratación térmica del yeso
(Macla, 2004) Astilleros García-Monge, José Manuel; Jordan, G.
Estudio de la influencia del carbonato en el crecimiento de la barita a nanoescala.
(Macla, 2004) Sánchez Pastor, Nuria; Pina Martínez, Carlos Manuel; Astilleros García-Monge, José Manuel; Fernández Díaz, María Lourdes
Geología de Grado en Química. Prácticas. 3. Periodicidad
(Reduca. Geología, 2010) Astilleros García-Monge, José Manuel; López De Andrés, María Sol; Viedma Molero, Cristóbal; Vindel Catena, Elena
Generalmente se define el cristal como un sólido en el que las innumerables partículas que lo constituyen están distribuidas periódicamente en las tres direcciones del espacio. Esta característica, la periodicidad, diferencia al cristal de todos los demás tipos de materiales y condiciona la existencia de otras propiedades, también exclusivas del medio cristalino, como son la simetría y la anisotropía. Esta práctica pretende que el alumno se familiarice con las herramientas básicas utilizadas en cristalografía para describir el medio periódico. La práctica presupone un conocimiento previo por parte del alumno del concepto de red cristalina y de cómo ésta se construye a partir de la traslación mediante vectores de los puntos equivalentes que la conforman. Debido a su utilidad pedagógica, gran parte de los ejercicios se realizarán sobre redes planas (bidimensionales), si bien en alguno de ellos se ha añadido una tercera dimensión, similar al mundo tridimensional del cristal real.
Malachite Crystallisation in a Diffusing-Reacting System
(Crystal Research and Technology, 1998) Astilleros García-Monge, José Manuel; Pina Martínez, Carlos Manuel; Fernández Díaz, María Lourdes; López De Andrés, María Sol
The crystallisation of malachite has been studied in a system involving the counter diffusion of Cu2+ and CO3 through a silica gel column at 25 ºC. In such a system supersaturation is a function of time and position along gel column. Under these conditions kinetic variables are required in order to justify nucleation behaviour. Supersaturation rate has revealed as the most important parameter controlling nucleation features (waiting time, position of the precipitate, and metastability levels). The results presented here confirm the general nucleation behaviour reported by Prieto et al., (1989, 1991, 1994) for other carbonates. On the other hand, supersaturation changes during crystallisation process control the morphological evolution of malachite crystals.
Agregados biomiméticos de calcita crecidos en hidrogel de gelatina: efecto combinado del Mg y la concentración de sólido en el gel
(Macla, 2015) Nindiyasari, Fitriana; Griesshaber, Erika; Fernández Díaz, María Lourdes; Astilleros García-Monge, José Manuel; Sánchez Pastor, Nuria; Ziegler, Andreas; Schmahl, Wolfgang W.
Uptake of dissolved lead by anhydrite surfaces
(Applied geochemistry, 2014) Morales, Juan; Astilleros García-Monge, José Manuel; Jiménez, Amalia; Göttlicher, Jorg; Steininger, Ralph; Fernández Díaz, María Lourdes
The fate of harmful metals in the Earth crust is importantly affected by sorption processes on mineral surfaces. Here, a study of the ability of anhydrite surfaces to uptake dissolved Pb is presented. Experiments were conducted at room temperature using initial Pb concentration ([Pbaq]0) ranging between 10 and 1000 mg/L and a batch type set-up. Inductively coupled plasma optical emission spectrometry analyses showed that [Pbaq] progressively decreased as the time of interaction increased, to reach a final steady state value of ~3.0 mg/L, irrespectively of [Pbaq]0. However, the time elapsed before the steady state value was reached strongly depended on [Pbaq]0, with the drop to this final value occurring in less than 1 day interaction when [Pbaq]0 ≥ 50 mg/L and after 20 days when [Pbaq]0 < 50 mg/L. Scanning Electron Microscopy and X-ray diffraction analyses confirmed the epitactic growth of anglesite (PbSO4) crystals on anhydrite surfaces when [Pbaq]0 ≥ 50 mg/L. X-ray Absorption Near Edge Structure spectroscopy points to a different sorption mechanisms when [Pbaq]0 < 50 mg/L. The results show that the epitactic growth of anglesite on anhydrite has no significant impact on the ability of anhydrite surfaces to remove Pbaq, which show equal effectiveness as that of gypsum surfaces. The high reactivity of anhydrite surfaces renders this phase potentially important in the control of the fate of dissolved metals in nature.