Mechanochemical Ionization: Differentiating Pressure-, Shear-, and Temperature-Induced Reactions in a Model Phosphate

Abstract Using density-functional theory-based molecular dynamics simulations, we study stress and temperature-induced chemical reactions in bulk systems containing triphosphoric acid zinc phosphate molecules. The nature of the products depends sensitively on imposed conditions, e.g., isotropic even more so shear create (zwitter-) ionic products. Free ions also emerge from thermal cycles, but are endothermic rather than exothermic as for stress-induced transitions atoms remain four-coordinated. Hydrostatic stresses required to occur lie well below those typical tribological micro-contacts stiff solids further reduced by shear. Before change their coordination under stress, proton mobility increases, i.e., hydrogen start oxygen atom they bonded within 10 ps time scales. hydrostatic this is with increasing Our finding suggests that materials which number, nature, sensitive cannot have a well-defined position triboelectric series, since local contact generally depend stiffness counter body. Moreover, our simulations do not support idea tribo-contact commonly would be obtained through heating alone. Graphical