Intense Mechanoluminescence and Gas Phase Reactions from the Sonication of an Organic Slurry

Mechanoluminescence is typically produced by grinding, crushing, or scraping a crystal, which can give a faint glow of light, and was first reported by Francis Bacon in 1605. This light is a microdischarge produced by the local separation of charged surfaces, resulting in a spectrum of gas line emission and the crystal itself. We have produced mechanoluminescence via a new route, using acoustic cavitation. Upon sonication of slurries of resorcinol in long chain alkanes, intense mechanoluminescence is observed, up to 1000-fold increase in intensity over grinding. We have observed extensive atomic and molecular emission lines that have not been previously reported for mechanoluminescence. In addition, we have evidence of gas phase reactions taking place during the mechanoluminescent event.