Deliquescence and efflorescence of small particles: Unifying perspectives from nucleation theory

Conference · Mon Feb 23 04:00:00 EST 2009

OSTI ID:951298

McGraw, R; Lewis, E

We examine size dependent deliquescence/efflorescence phase transformation for particles down to several nanometers in size. A thin layer criterion (TLC) is introduced to define a deliquescence relative humidity (DRH) for small particles. The usual bulk deliquescence conditions are recovered in the limit of large dry particle size. Nano-size particles are shown to deliquesce to metastable states via a nucleation process at relative humidity just below the DRH. The nucleation barrier is located at a critical solution layer thickness and vanishes at the DRH defined by the TLC. Methods from nucleation theory form the basis for the analysis and yield new insights into the theory, facilitate the interpretation of measurements, and point to unification of deliquescence and efflorescence processes for particles in the nano regime. Methods include thermodynamic area constructions, Legendre transforms relating the binary free-energy surfaces for deliquescence and efflorescence processes, and application of nucleation theorems.

• Research Organization: Brookhaven National Laboratory
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 951298
• Report Number(s): BNL--82086-2009-CP; KJ0403000
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
77 NANOSCIENCE AND NANOTECHNOLOGY
AEROSOLS
FREE ENERGY
HUMIDITY
METASTABLE STATES
NANOSTRUCTURES
NUCLEATION
PARTICLE SIZE
PHASE TRANSFORMATIONS
THERMODYNAMICS