Struvite Grown in Gel, Its Crystal Structure at 90 K and Thermoanalytical Study

In this article, we report the crystallization of struvite in sodium metasilicate gel by single diffusion gel growth technique. The obtained crystals have a very rich morphology displaying 18 faces. In this study, the habit and morphology of the obtained struvite crystals are analyzed. The crystals...

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Bibliographic Details
Main Authors: Jolanta Prywer, Lesław Sieroń, Agnieszka Czylkowska
Format: Article
Language:English
Published: MDPI AG 2019-02-01
Series:Crystals
Subjects:
Online Access:https://www.mdpi.com/2073-4352/9/2/89
Description
Summary:In this article, we report the crystallization of struvite in sodium metasilicate gel by single diffusion gel growth technique. The obtained crystals have a very rich morphology displaying 18 faces. In this study, the habit and morphology of the obtained struvite crystals are analyzed. The crystals were examined and identified as pure struvite by single X-ray diffraction (XRD). The orthorhombic polar noncentrosymmetric space group <i>Pmn</i>2<sub>1</sub> was identified. The structure of the crystal was determined at a temperature of 90 K. Our research indicates a lack of polymorphism, resulting from the temperature lowering to 90 K, which has not been previously reported. The determined unit cell parameters are as follows <i>a</i> = 6.9650(2) Å, <i>b</i> = 6.1165(2) Å, <i>c</i> = 11.2056(3) Å. The structure of struvite is presented here with a residual factor R1 = 1.2% at 0.80 Å resolution. We also present thermoanalytical study of struvite using thermal analysis techniques such as thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA).
ISSN:2073-4352