title: Observation of the binary coalescence and equilibration of micrometer-sized droplets of aqueous aerosol in a single-beam gradient-force optical trap.
abstract: The binary coalescence of aqueous droplets has been observed in a single-beam gradient-force optical trap. By measuring the time-dependent intensity for elastic scattering of light from the trapping laser, the dynamics of binary coalescence have been examined and the time scale for equilibration of a composite droplet to ambient conditions has been determined. These data are required for modeling the agglomeration of aqueous droplets in dense sprays and atmospheric aerosol. Elastic-light scattering from optically trapped particles has not been used previously to study the time-resolved dynamics of mixing. It is shown to offer a unique opportunity to characterize the binary coalescence of aqueous droplets with radii from 1 to 6 μm. The study of this size regime, which cannot be achieved by conventional imaging methods, is critical for understanding the interactions of droplets in the environment of dense sprays.
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Power
authors.forename: J P
authors.initials: JP
authors.lastname: Reid
authors.forename: S
authors.initials: S
authors.lastname: Anand
authors.forename: D
authors.initials: D
authors.lastname: McGloin
authors.forename: A
authors.initials: A
authors.lastname: Almohammedi
authors.forename: A
authors.initials: A
authors.lastname: Almohamedi
authors.forename: N S
authors.initials: NS
authors.lastname: Mistry
authors.forename: A J
authors.initials: AJ
authors.lastname: Hudson
mesh_terms: D000336:Aerosols; D006358:Hot Temperature; D055616:Microtechnology / Q000379:methods*; D052898:Optical Tweezers; D012492:Salts / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D000336:Aerosols; D012492:Salts; D014867:Water