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The synthesis of minerals should play a crucial role in the development of new and advanced materials. Since 2016, a renewal of interest to enlarge the mineral synthesis towards industrial requirements has been observed, especially thanks to three main recent papers. The innovative process exposed combines a continuous process with the use of supercritical water. In addition to curtail synthesis times, this process offers a control on the particle characteristics (size, crystallinity, structure, etc.) and a capacity to be easily transferable at an industrial scale. This innovative concept is demonstrated with the synthesis of three minerals which are the talc (a phyllomineral), the xonotlite and the tobermorite (two inominerals). This article proposes an overview of the possibilities to synthesize nanominerals in continuous processing for the development of advanced materials with promising industrial applications. [ABSTRACT FROM AUTHOR]

Abstract: This contribution gives a comprehensive review about the progress in preparation methods, properties and applications of the different synthetic talc types: i) crystalline nanotalc synthesized by hydrothermal treatment; ii) amorphous and/or short‐range order nanotalc obtained by precipitation, and iii) organic–inorganic hybrid talc‐like structures obtained through a sol–gel process or a chemical grafting. Several advantages of nanotalc such as high chemical purity, high surface area, tunable submicronic size, high thermal stability, and hydrophilic character (leading to be the first fluid mineral) are emphasized. Synthetic nanotalc applications are also considered including its use as nanofiller in composite materials, as absorbers of organic compounds, as anticorrosion coatings and as agents for cosmetic applications. Regarding their high industrial application potential, intensive research has been carried out to better understand their behavior and develop processes to produce them. To facilitate further research and development, scientific and technical challenges are discussed in this Review article. [ABSTRACT FROM AUTHOR]

Herein we introduce a powerful and fast method to produce nanominerals using a bottom up approach. The supercritical hydrothermal flow synthesis is exploited to produce model nanominerals by mimicking natural environments at high temperatures under pressure. This innovative concept is demonstrated with the talc synthesis; this represents a major technical breakthrough since it allows decreasing the mineral-synthesis time from tens of hours to tens of seconds. Through this example, we show these nanominerals exhibit new crystal-chemistry signals and new properties. This approach provides a means to reproduce the early stages of formation of minerals in different natural environments from sedimentary environments (low temperature and pressure) to hydrothermal/metamorphic environments (high temperature and high pressure). [ABSTRACT FROM AUTHOR]

Abstract: Over the past 2years, the synthetic process of talc particles has evolved considerably, leading to an inexpensive, convenient, and rapid process that is compatible with industrial requirements. In addition to facilitate the synthetic talc preparation, the evolution of the synthesis process has led to an improved crystallographic arrangement of the talc particles in both the c* direction and (ab) plane. In the present study, the most recent process was investigated with respect to the reaction time, temperature, pressure, pH, and salt concentration to determine the optimal reaction parameters. In the geomaterial industry, X-ray diffraction is routinely used for powder material characterization; the crystallinity of our synthetic talc was evaluated by this technique through measurements of the Coherent Scattering Domain (CSD) size. A crystalline lamellarity index was defined as the ratio between the CSD size values in the (ab) plane and c⁎ direction. These crystallinity characteristics were used to define the quality of the synthetic talc and its suitability for potential industrial markets. [Copyright &y& Elsevier]

The cover page of the journal "Angewandte Chemie" is presented.