Single levitated aerosol particles

LABORATORY EXPERIMENTS ON SINGLE LEVITATED AEROSOL PARTICLES... 

Laboratory Experiments on Single Levitated Aerosol Particles... 

In our experiments, many of the above mentioned difficulties could be overcome, as we observe single levitated aerosol particles over an extended period of time. By this means we are able to perform a thorough study of the thermodynamics and kinetics of the freezing of water, sulfuric acid and PSC droplets, and perform first measurements of HCl uptake into sulfuric acid droplets under stratospheric conditions. 

James Davis is the inventor of the levitation machine, with which a single aerosol particle can be suspended in mid-air in order to study its equilibrium and rate processes without resorting to averaging among many particles. He contributes a very strong chapter on Microchemical Engineering that involves chemical reactions, transport processes, thermodynamics and physical processes. 

Davis, E. J., A History of Single Aerosol Particle Levitation, Aerosol Sci. Technol., 26, 212-254 (1997). 

Delhaye and Dhamelincourt (1975) were the first to combine a Raman spectrometer with a microscope. Kiefer (1988) described the Raman spectroscopy of single particles of aerosols by the optical levitation technique, an approach which is even possible with a compact spectrometer (Hoffmann et al., 1992). Raman spectra recorded with NIR FT Raman microscopes have proven the value of this technique (Messerschmidt and Chase, 1989 Bergin and Shurwell, 1989 Simon and Sawatzki, 1991). Examples of micro Raman spectra obtained from different spots on certain biological samples have been published (Schrader, 1990 Puppels et al., 1991). 

Peng CG, Chow AHL, Chan CK. Study of the hygroscopic properties of selected pharmaceutical aerosols using single particle levitation. Pharm Res 2000, 17, 1104-1109. 

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