MORALES FLÓREZ , Víctor

El trabajo que se presenta a continuación se enmarca en el campo de la Ciencia de los Materiales. Tratamos de aportar un poco más de luz al conocimiento de las propiedades y de la estructura de los materiales, desde los puntos de vista experimental y teórico. Por un lado, el estudio de las propiedades se aborda con diversas técnicas de análisis...

Structure simulation algorithms of random packing of spheres and bricks have been developed. These algorithms were used to reproduce the nanostructure of the cementitious calcium silicate hydrates. The textural parameters (specific surface area, porosity, pore size, etc.) of a calcium silicate hydrates (C-S-H) sample, the main binding phase of...

Solid colloidal ensembles inherently contain water adsorbed from the ambient moisture. This water, confined in the porous network formed by the building submicron spheres, greatly affects the ensemble properties. Inversely, one can benefit from such influence on collective features to explore the water behavior in such nanoconfinements....

The nanostructure of supercritically dried calcium silicate hydrates was researched. This particular drying procedure was used to avoid nanostructure modifications due to conventional drying processes. Thus, in this study, the as-precipitated cementitious C-S-H structure was obtained for the first time. A specific surface area 20 % larger than...

The nanostructure of the main binding phase of the hydrated cements, the calcium silicate hydrates (C-S-H), and their structural changes due to aqueous carbonation have been characterized using TEM, nitrogen physisorption, and SAXS. Synthetic C-S-H has been used for this purpose. Two different morphologies were identified, similar to the high...

For decades, enormous investigation effort has been devoted to the fabrication of new ceramic matrix composites with enhanced mechanical properties. One of the most explored strategies is the addition of carbon allotropic phases such as carbon nanotubes, graphene, and carbon nanofibers due to their outstanding properties. In this review, the...

The effect of intergranular water on the conductivity of polycrystalline brucite, Mg(OH)2, was investigated using impedance spectroscopy at 2 GPa, during consecutive heating-cooling cycles in the 298-980 K range. The grain boundary hydration levels tested here span water activities from around unity (wet conditions) down to 10-4 (dry...

A cellular automata model has been developed to study the sintering behavior of ceramic particles. In this model, the only physical rule that drives the evolution of the system is to reduce the energy at the interface between the mass cells and the void cells. The meaning of several computational parameters, such as particle size or...

Processes of carbonation of calcium-rich aqueous industrial wastes from acetylene production were performed mimicking rock weathering, using the atmospheric carbon dioxide as reactant. This residue was carbonated exposing it to the air in artificial pools with controlled solid-to-liquid and surface-to-volume ratios, and the efficiency of this...

The aim of this study was to investigate the adsorption of basic yellow, a cationic dye, from aqueous solution by natural stevensite, with 104m2/g of specific surface area. The kinetics and the effects of several experimental parameters such as the pH of the solution, adsorbent dose and initial dye concentration were researched using a batch...

En este trabajo y con el objetivo de conjugar el punto de vista atomístico y coloidal, presentamos un método com- putacional Monte Carlo que reproduce el empaqueta- miento coloidal de nano-partículas esféricas cristalinas de tipo Tobermorita. Variando los parámetros computa- cionales de empaquetamiento diferentes estructuras tipo Low Density...

Supercritically dried composites have already been analysed and proposed as carbon dioxide sequesters. However, the economical and energetic costs of the supercritical drying process had to be re-evaluated, and were eventually found not to enhance the feasibility of the proposed route for CO2 mineral sequestration. Different composites series...

Se han obtenido aerogeles híbridos de sílice orgánico-inorgánico por aplicación de ultrasonidos de alta potencia en los precursores líquidos y posterior secado del gel húmedo en condiciones supercríticas en etanol. Las cadenas orgánicas no se degradan térmicamente y aceleran el proceso de contracción de la red por activación térmica. Los...

This work explored several synthesis routes to obtain calcium silicates from different calcium-rich and silica-rich industrial residues. Larnite, wollastonite and calcium silicate chloride were successfully synthesised with moderate heat treatments below standard temperatures. These procedures help to not only conserve natural resources, but...