Imaging Dissolution Dynamics of Individual NaCl Nanoparticles during Deliquescence with Transmission Electron Microscopy.

Water vapor condensation on hygroscopic aerosol particles plays an important role in cloud formation, climate change, secondary aerosol formation, and aerosol aging. Conventional understanding considers deliquescence of nanosized hygroscopic aerosol particles a nearly instantaneous solid to liquid phase transition. However, the nanoscale dynamics of water condensation and aerosol particle dissolution prior to and during deliquescence remain obscure due to a lack of high spatial and temporal resolution single particle measurements.

Toward an Understanding of Uric Acid Particle Dissolution: Surface and Bulk-Driven Water Activity.

Uric acid particles contribute to kidney stones, and natural processes for the elimination of stones depend on solute-solvent interactions. The process of uric acid dissolution has previously been understood via the lens of solubility; however, for pure and mixed salt solutions, these approaches do not provide a comprehensive picture of nanoscale particle solution thermodynamics. Unlike solubility measurements, water activity measurements provide us with information about the chemical potential responsible for the migration of water molecules driving the dissolution of particles.

Liquid-Liquid Phase Separation Can Drive Aerosol Droplet Growth in Supersaturated Regimes.

It is well known that atmospheric aerosol size and composition impact air quality, climate, and health. The aerosol composition is typically a mixture and consists of a wide range of organic and inorganic particles that interact with each other. Furthermore, water vapor is ubiquitous in the atmosphere, in indoor air, and within the human body's respiratory system, and the presence of water can alter the aerosol morphology and propensity to form droplets.

Solubility Considerations for Cloud Condensation Nuclei (CCN) Activity Analysis of Pure and Mixed Black Carbon Species.

Black carbon (BC) is an aerosol that is released into the atmosphere due to the incomplete burning of biomass and can affect the climate directly or indirectly. BC commonly mixes with other primary or secondary aerosols to undergo aging, thereby changing its radiative properties and cloud condensation nuclei (CCN) activity. The composition of aged BC species in the atmosphere is difficult to measure with high confidence, so their associated CCN activity can be uncertain.

Electric Field-Induced Water Condensation Visualized by Vapor-Phase Transmission Electron Microscopy.

Understanding the nanoscale water condensation dynamics in strong electric fields is important for improving the atmospheric modeling of cloud dynamics and emerging technologies utilizing electric fields for direct air moisture capture. Here, we use vapor-phase transmission electron microscopy (VPTEM) to directly image nanoscale condensation dynamics of sessile water droplets in electric fields. VPTEM imaging of saturated water vapor stimulated condensation of sessile water nanodroplets that grew to a size of ∼500 nm before evaporating over a time scale of a minute.