Mechanism of reaction acceleration in microdroplets
In plain words
Reactions in sprayed droplets are often reported to run much faster than in a flask. Proposed reasons include strong electric fields at the surface, partial drying of reactants and evaporation that concentrates them.
Precise statement
For bimolecular reactions in aqueous microdroplets of radius 1 to 50 micrometers, determine the true acceleration factor of the rate constant relative to bulk after correcting for evaporation, concentration changes, gas-phase reactions in the mass spectrometer inlet and ion-source chemistry, and identify the dominant cause (interfacial electric field, partial solvation, interfacial pH, charge). An answer is a corrected acceleration factor for benchmark reactions plus a mechanism that predicts it.
What would settle it
In situ, inlet-free kinetic measurements (for example fluorescence or Raman in levitated droplets) matched to simulations of interfacial reaction free energies.