2026-10-14T05:36:24Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34015049 2026-09-28T15:17:18Z category_1 category_4 category_915 category_24 category_873 category_39 category_734 category_61 category_69 category_135 portal_63 item_type_3 month_year_09_2026

Microlightning: Avalanche-Driven Blue Emission and Reactive-Species Formation in Charged Microdroplets Dai-Bei Yang (10429702) Xiangyu Chen (838888) Tarek Trabelsi (4524523) Joseph S. Francisco (1414543) Biophysics Biochemistry Physical Sciences not elsewhere classified Evolutionary Biology Chemical Sciences not elsewhere classified Ecology Biological Sciences not elsewhere classified Developmental Biology Inorganic Chemistry Computational Biology size interfacial plasma new phenomenon referred links droplet charging g ., oh experiments performed without enhancing gas environments enable detectable n electrostatic energy stored bridging microscopic discharges accelerated organic reactions initiate chemical reactions promote significant reactive including molecular excitation host redox chemistry generating reactive oxygen driven blue emission understanding microdroplet reactivity 2 </ sub system emission blue light chemical consequences chemical activation ∼ 1000 seed electrons resulting reactive reaction platforms rayleigh limit predictive basis precursors relevant photon production observation adds necessary conditions mechanistic origin macroscopic lightning growing body findings characterize field approximation emit flashes charged microdroplets bulk solution atmospheric chemistry Charged microdroplets have recently been observed in experiments performed without a strong externally imposed field to emit flashes of blue light and initiate chemical reactions, a new phenomenon referred to as “<i>microlightning</i>.” This observation adds to a growing body of evidence that charged microdroplets can host redox chemistry not accessible in bulk solution, yet the mechanistic origin and chemical consequences of this emission remain poorly understood. A fundamental chemical question regarding spontaneous microdroplet reactivity thus naturally arises: can electrostatic energy stored on a microdroplet be converted into chemical activation, including molecular excitation, ionization, and reactive-species formation? Here, we establish a framework that links droplet charging, avalanche dynamics, and the resulting reactive-species and photon production. Under the local-field approximation, Townsend theory establishes analytical scaling for finite avalanches in isolated heavily charged droplets; particle-in-cell Monte Carlo simulations quantify multiplication up to ∼1000 and resolve electron fates via ionization, excitation, and attachment, generating reactive oxygen and hydrogen species (e.g., OH^•, O₂^•–, and H^•) or their precursors relevant to microdroplet-accelerated organic reactions and atmospheric chemistry. Further, pairs of oppositely charged droplets create intensified fields that enable detectable N₂ second-positive-system emission and promote significant reactive-species formation. Finally, we identify the necessary conditions for microlightning: micrometer-scale droplets carrying substantial fractions of the Rayleigh limit, seed electrons, and ionization-enhancing gas environments, providing a predictive basis for understanding microdroplet reactivity in electrospray and other reaction platforms. These findings characterize <i>microlightning</i> as a form of finite-size interfacial plasma-chemistry, bridging microscopic discharges with macroscopic lightning. 2026-09-28T00:00:00Z Dataset Dataset 10.1021/jacs.6c14162.s002 https://figshare.com/articles/dataset/Microlightning_Avalanche-Driven_Blue_Emission_and_Reactive-Species_Formation_in_Charged_Microdroplets/34015049 CC BY-NC 4.0