THE COLLECTION OF ULTRAFINE AEROSOL-PARTICLES FOR ANALYSIS BY TRANSMISSION ELECTRON-MICROSCOPY, USING A NEW THERMOPHORETIC PRECIPITATOR

Very little instrumentation exists to characterize individual ultrafine aerosol particles. A thermophoretic precipitator has been developed to deposit uniform ultrafine particle samples onto transmission electron microscope grids, thus allowing the analytical techniques now available to be utilised. Details are given of the precipitator's design, and preliminary collection results using an ultrafine silver aerosol are presented. Comparison of data from thermophoretically collected samples and samples collected by diffusion indicates a positive collection ability at nm particle sizes, but at lower deposition velocities than predicted.