Crystal Growth of Smectite: A Study Based on the Change in Crystal Chemistry and Morphology of Saponites with Synthesis Time

Abstract

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.The crystal growth of smectite: A study based on the change in crystal-chemistry and morphology of saponites with synthesis time

The evolution of saponite: An experimental study based on crystal chemistry and crystal growth

“…The S of the bands is proportional to the concentration of absorbing centers of the given OH types, assuming that the absorption coefficients are constant for all metal OH stretching vibration bands (e.g., Slonimskaya et al, 1986;Petit et al, 2004;Madejová et al, 2017). The decomposition of the spectral envelop into bands was undertaken by the Peakfit software package, using four Gauss-Lorentz cross-product (Zhang et al, 2020). Correspondingly, the dissolution extent (i.e., the dissolution ratio of precursors) can be estimated by…”

“…These processes result in variations in crystal-chemistry and morphology of smectite, due to physicochemical condition changes that frequently occur in natural systems (Eberl, 1984;Merriman, 2005;Galán and Ferrell, 2013). Previous studies have reported that smectites evolve from poorly crystalline precursors in various environments (Zhou and Fyfe, 1989;Banfield and Eqqleton, 1990;Kawano and Tomita, 1992;Christidis, 2001; Christidis and Huff, 2009;Baldermann et al, 2015;Cuadros et al, 2017;Zhang et al, 2020), which is important for This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America.…”

“…However, literature dedicated to such evolution mainly focused on the alterations of primary minerals into smectites instead of the evolution of smectites themselves. So far, very limited studies have been devoted to the cognition of smectite self-evolution (Christidis, 2001;Baldermann et al, 2015;Zhang et al, 2020). Christidis (2001) attempted to develop the growth patterns of natural smectite via morphological analyses.…”

“…Baldermann et al (2015) have reported on the evolution of particle size and crystal chemistry of synthetic Fe/Mgsaponite. Recently, we highlighted the growth kinetics of smectite by investigating cation distribution and morphology evolution (Zhang et al, 2020). These studies have greatly enhanced our understanding of smectite evolution, but many questions remain unanswered.…”

“…Hence, the synthesis of saponite is advantageous to investigate smectite evolution, notably during the early-stage growth, which is scarcely observed in nature. Based on our previous study about morphology and crystal-chemistry of saponite with the change of hydrothermal time (Zhang et al, 2020), we further expand on the evolution trend of saponite by using the parameters of crystal-chemistry and crystal growth of saponite with the change of hydrothermal temperature in present study. The Mg-and Ni-saponite system was chosen as the study of object because they can be easily synthesized.…”