Microdroplet Mechanochemistry

Water, mother of all fluids, long considered passive, is now shown to be highly active in the form of droplets, where chemical reactions requiring intense stimuli, happen rapidly. Discoveries from our lab in the recent past have shown that hard, common minerals such as quartz and ruby disintegrate spontaneously to form nanoparticles in charged water microdroplets. This occurs due to a combination of intense electric fields, reactive chemical species and mechanical forces in the droplets, acting in concert on the minerals. Subsequent studies have shown that this is a generic process occurring in a variety of materials. This evolving field of microdroplet mechanochemistry presents a low energy, reagent-free and ambient method for water-based transformations of materials. As the process occurs in milliseconds rather than the millennia conventionally associated with mineral disintegration, it effectively compresses geological time scales. The possibilities of such a process as a new method of materials discovery and green manufacture is outlined here. This positions water as a green factory making materials sustainably.