Fast-Geomimicking using Chemistry in Supercritical Water

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). Small talc: The supercritical hydrothermal flow synthesis is a new method to produce model nanominerals, such as nano‐talc, in just a few tens of seconds. As well as having different spectroscopic signals to natural talc, the nano‐talc has new properties, such as its hydrophilic character, making it the first fluid talc filler for new applications.