Electric Fields Enhance Ice Formation from Water Vapor by Decreasing the Nucleation Energy Barrier

• Published in: Colloids and interfaces Vol. 6; no. 1; p. 13
• Main Authors: Santos, Leandra P., da Silva, Douglas S., Galembeck, André, Galembeck, Fernando
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2022
• Subjects: Aluminum; Cellulose; Charge density; classical nucleation theory; Crystal surfaces; electric field; Electric fields; Electrification; Electrostatics; Energy; environmental electricity; Faraday cage; Graphite; Ice formation; ice nucleation; Intermolecular forces; non-classical particle formation and growth; Nucleation; Phase transitions; Potential gradient; Power supply; Supersaturation; Surface charge; Surface tension; Temperature; Thunderstorms; Water vapor; Brazil
• ISSN: 2504-5377; 2504-5377
• DOI: 10.3390/colloids6010013

Video images of ice formation from moist air under temperature and electric potential gradients reveal that ambient electricity enhances ice production rates while changing the habit of ice particles formed under low supersaturation. The crystals formed under an electric field are needles and dendrites instead of the isometric ice particles obtained within a Faraday cage. Both a non-classical mechanism and classical nucleation theory independently explain the observed mutual feedback between ice formation and its electrification. The elongated shapes result from electrostatic repulsion at the crystal surfaces, opposing the attractive intermolecular forces and thus lowering the ice-air interfacial tension. The video images allow for the estimation of ice particle dimensions, weight, and speed within the electric field. Feeding this data on standard equations from electrostatics shows that the ice surface charge density attains 0.62–1.25 × 10−6 C·m−2, corresponding to 73–147 kV·m−1 potential gradients, reaching the range measured within thunderstorms. The present findings contribute to a better understanding of natural and industrial processes involving water phase change by acknowledging the presence and effects of the pervasive electric fields in the ambient environment.