CONTINUOUS PARTICLE SAMPLER STUDY PROGRAM
Abstract
A method of absolute calibration to relate replica size to original droplet size was developed. Aspergillus niger spores, 3 microns in diameter, do not dissolve in the solvents used to soften the Formvar coating. These spores are mixed in the water from which the droplets are formed. Then counting the spores visible in the droplet replica permits estimating the mass of the original droplet. The correction factor (replica diameter/droplet diameter) is unity for small droplets of diameter thinner than the Formvar, and greater than unity for larger droplets. The correction factor appears to be a unique function of the final dry Formvar thickness, implying that the droplet final shape is defined after much of the solvent has evaporated. Theoretical studies involving a computer program were also conducted on droplet deformation as a function of water/Formvar solution/air interface surface tensions. The various interrelated problems of flocculation, encapsulation and replication, blushing, blistering, crystal melting and droplet evaporation, solution blowoff, bubble formation, and film sticking are considered, and the design of an improved device is discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1963
- Accession Number
- AD0643000
Entities
People
- Paul B. Maccready
- Robin E. Williamson