Lanthanide Luminescence Revealing the Phase Composition in Hydrating Cementitious Systems

Abstract

The hydration process of Portland cement in a cementitious system is crucial for development of the high‐quality cement‐based construction material. Complementary experiments of X‐ray diffraction analysis (XRD), scanning electron microscopy (SEM) and time‐resolved laser fluorescence spectroscopy (TRLFS) using europium (Eu(III)) as an optical probe are used to analyse the hydration process of two cement systems in the absence and presence of different organic admixtures. We show that different analysed admixtures and the used sulphate carriers in each cement system have a significant influence on the hydration process, namely on the time‐dependence in the formation of different hydrate phases of cement. Moreover, the effect of a particular admixture is related to the type of sulphate carrier used. The quantitative information on the amounts of the crystalline cement paste components is accessible via XRD analysis. Distinctly different morphologies of ettringite and calcium−silicate−hydrates (C−S−H) determined by SEM allow visual conclusions about formation of these phases at particular ageing times. The TRLFS data provides information about the admixture influence on the course of the silicate reaction. The dip in the dependence of the luminescence decay times on the hydration time indicates the change in the structure of C−S−H in the early hydration period. Complementary information from XRD, SEM and TRLFS provides detailed information on distinct periods of the cement hydration process.

Classical and new insights into the methodology for characterizing the hydration of calcium aluminate cements

“…Recently, it was also found that luminescence methods can be used to study the effect of hydration on the physicochemical properties of the Rare Earth Elements [REE] in OPC pastes (11)(12)(13)(14).…”

Crystal Structure and Photophysical Properties of a Novel Dy-Hg Isonicotinic Acid Compound with One-Dimensional Chain-Like Cations

“…It is well-known that most of lanthanide(III) ions (not including La 3+ and Lu 3+ ions) can usually show fine photoluminescence performances and, in recent years, new lanthanide materials with interesting photoluminescence properties have drawn more and more attention from the researchers in chemical, physical, material and other domains. [1][2][3][4][5] As of today, a large number of researchers have been devoting themselves to the preparation, structures, physical and chemical characterization of new lanthanide materials, in order to explore their various potential applications in luminescent probes, cell imaging, catalysts, magnetic materials, electrochemical displays, sensors, light-emitting diodes, and so forth. [6][7][8][9][10][11][12] Relative to the large number of investigations on the photoluminescence behavior of new lanthanide materials, only very few investigations on the semiconductor properties of lanthanide materials have been explored so far and, therefore, more studies are still necessary.…”