Listar QICM - Artículos por título
Mostrando ítems 1-20 de 96
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2D Corrugated Magnesium Carboxyphosphonate Materials: Topotactic Transformations and Interlayer “Decoration” with Ammonia
(American Chemical Society, 2012-06-29)In this paper we report the synthesis and structural characterization of the 2D layered coordination polymer Mg(BPMGLY)(H2O)2 (BPMGLY = bis-phosphonomethylglycine, (HO3PCH2)2N(H)COO2−). The Mg ion is found in a slightly ... -
A Self-Folding Polymer Film Based on Swelling Metal–Organic Frameworks
(Wiley-VCH Verlag GmbH & Co., 2018-10-23)Herein, we exploit the well-known swelling behaviour of metal–organic frameworks (MOFs) to create a selffolding polymer film. Namely, we show that incorporating crystals of the flexible MOF MIL-88A into a polyvinylidene ... -
Accuracy in Cement Hydration Investigations: Combined X-ray Microtomography and Powder Diffraction Analyses
(MDPI, 2021-11-17)Cement hydration is a very complex set of processes. The evolution of the crystalline phases during hydration can be accurately followed by X-ray powder diffraction data evaluated by the Rietveld method. However, accurate ... -
Accuracy in Rietveld quantitative phase analysis: a comparative study of strictly monochromatic Mo and Cu radiations
(Willey online Library, 2016)This study reports 78 Rietveld quantitative phase analyses using Cu K 1, Mo K 1 and synchrotron radiations. Synchrotron powder diffraction has been used to validate the most challenging analyses. From the results for ... -
Alite-belite-ye'elimite cements: Effect of dopants on the clinker phase composition and properties
(2018-10-30)Clinkers with alite-belite-ye'elimite (ABY) are considered as eco-friendly cements. Clinkering (2 Kg) of two types of ABY clinkers was optimized: standard-ABY, with CaF2 and ZnO as dopants (32.6 wt% alite, 30.4 wt% β-C2S ... -
Aluminum Hydroxide Gel Characterization within a Calcium Aluminate Cement Paste by Combined Pair Distribution Function and Rietveld Analyses
(Elsevier, 2017-06)There are many commercially important multiphase materials which contain amorphous phases, such as cement pastes, porcelains, glass-ceramics or pharmaceutical compounds. However, the analysis of amorphous phase(s) within ... -
Aluminum-rich belite sulfoaluminate cements: clinkering and early age hydration
(Elsevier, 2009)Belite sulfoaluminate (BSA) cements have been proposed as environmentally friendly building materials, as their production may release up to 35% less CO2 into the atmosphere when compared to ordinary Portland cements. ... -
Amorphous determination in calcium sulfoaluminate materials by external and internal methods
(ICE Publishing, 2014)External standard methodology has been successfully applied to quantify the known amounts of amorphous component that are increasingly added to cement-related materials. The consistency and accuracy of the methodology were ... -
Assessment of ATR-FTIR spectroscopy with multivariate analysis to investigate the binding mechanisms of Ag and TiO2 nanoparticles to Chelex®-100 or Metsorb™ for the DGT technique
(The Royal Society of Chemistry, 2020-01-09)Studying nanomaterials' ecotoxicology is not new but there are still gaps in our understanding of their fate in the environment. A major challenge is lack of reliable tools to measure available concentrations of nanoparticles ... -
Assessment of the quantitative accuracy of Rietveld/XRD analysis of crystalline and amorphous phases in fly ash
(2017)An internal standard method based on Rietveld/XRD whole-pattern fitting analysis of fly ash is used to assess the quantitative accuracy to determine its crystalline and amorphous phases under various conditions such as ... -
Belite cements and their activation
(Elsevier, 2020-11)Belite cements, BCs, containing mainly belite, alite and calcium aluminates, are currently used as low heat cements. These binders produce high amounts of C–S–H gel and have very good durability properties which are reviewed. ... -
Belite hydration at high temperature and pressure by in situ synchrotron powder diffraction
(2020-10-16)Portland cements are currently used as Oil‐Well‐Cements for the sheath between the metal casing and the borehole. At high pressures and temperatures, the resulting C-S-H gel(s) is partly unstable and it can react to give ... -
“Breathing” in Adsorbate-Responsive Metal Tetraphosphonate Hybrid Materials
(Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim, 2009-05-28)The structures of various layered calcium tetraphosphonates (CaH6DTMP; H8DTMP=hexamethyl- tetrakis(methylenephosphonic acid)), have been determined. Starting from CaH6DTMP·2H2O, thermal treatment and subsequent exposure ... -
Calcium aluminate cement conversion analysed by ptychographic nanotomography
(Elsevier, 2020-08-17)Calcium aluminate cements are used for special applications but are nowadays banned for general structural purposes due to the calcium aluminate hydrate conversion, that has led, for concretes fabricated with high water ... -
Chemistry and Mass Density of Aluminum Hydroxide Gel in Eco-Cements by Ptychographic X-ray Computed Tomography
(ACS, 2017)Eco-cements are a desirable alternative to ordinary Portland cements because of their lower CO2 footprints. Some ye’elimite-based ecocements are attracting a lot of interest. Understanding the reasons for the mechanical ... -
Clinkering and hydration of belite-ye'elimite-alite cement
(Elsevier, 2017)Some belite-ye´elimite-ferrite (BYF) cements present low mechanical strengths mainly due to the slow reactivity of belite. A solution to this problem may be the activation of BYF clinkers by preparing them with a coexistence ... -
Common Structural Features in Calcium Hydroxyphosphonoacetates. A High-Throughput Screening
(2011-03-11)R,S-Hydroxyphosphonoacetic acid (H3HPA) is an inexpensive multidentate organic ligand widely used for the preparation of organo-inorganic hybrid materials. There are reports of several crystal structures and the variability ... -
A comparative study of experimental configurations in synchrotron pair distribution function
(MDPI - Publisher of Open Access Journals, 2019-04-25)The identification and quantification of amorphous components and nanocrystalline phases with very small crystal sizes, smaller than ~3 nm, within samples containing crystalline phases is very challenging. However, this ... -
Crystal engineering in confined spaces. A novel method to grow crystalline metal phosphonates in alginate gel systems
(The Royal Society of Chemistry, 2012)In this paper we report a crystal growth method for metal phosphonate frameworks in alginate gels. It consists of a metalcontaining alginate gel, in which a solution of phosphonate ligand is slowly diffused. Crystals of ... -
Difracción de rayos-x (DRX) y cementos: desde la investigación hasta el control de calidad
(2019-06-20)Los materiales de construcción son componentes complejos de gran interés comercial. Por ello, el conocimiento cuantitativo de su mineralogía a través de la difracción de rayos X (DRX) es de crucial importancia para optimizar ...