Tuesday, February 25, 2025 - 3:30pm
Interfacial tension controls many important nanoparticle physicochemical properties. As the particle diameter decreases the vapor pressure over a curved particle increases and the melting point decreases. This, in turn, influences phase transitions (nucleation of new particles, deliquescence and efflorescence, ice nucleation, and cloud droplet nucleation), the degree to which particles take up water at elevated relative humidity, and the tendency of particles to evaporate. Current theories are based on Gibbs’ thermodynamics, which yield the Kelvin equation and Gibbs-Thomson equation. Although these theories are broadly valid, there are a number of unresolved questions applying these equations to real-world nanoparticle processes. In this presentation I will discuss a broad swath of experimental data for cloud droplet nucleation and nanoparticle melting for sub-1 micron sized particles. Special focus will be on the question of how uncertainties in the interfacial tension prevent a more fundamental theoretical understanding of the existing data.

Speaker: 

Markus Petters

Institution: 

UC Riverside

Location: 

RH 104