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

Author(s)

Santos, Leandra P. ; da Silva, Douglas S. ; Galembeck, Andre ; Galembeck, Fernando

• Document type: Journal article
• Source: COLLOIDS AND INTERFACES; v. 6, n. 1, p. 15-pg., 2022-03-01.

Abstract

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 x 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. (AU)

• FAPESP's process: 19/04565-9 - Conductive inks, adhesives and coatings made with exfoliated graphite, applied to making electrical components and circuits
• Grantee: Leandra Pereira dos Santos
• Support Opportunities: Scholarships in Brazil - Innovative Research in Small Business - PIPE
• FAPESP's process: 18/00834-2 - Conductive inks, adhesives and coatings made with exfoliated graphite, applied to making electrical components and circuits
• Grantee: Fernando Galembeck
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• FAPESP's process: 14/50906-9 - INCT 2014: in Functional Complex Materials
• Grantee: Fernando Galembeck
• Support Opportunities: Research Projects - Thematic Grants