Geração de nanopartículas monodispersas em correntes gasosas

Abstract

DMA or Differential Mobility Analyzer is a device used to classify nanoparticles electrically charged based on the ability the same in being attracted by the electric field. That is, starting with a polydispersed aerosol particles having diameters of different sizes, one obtains monodisperse aerosol with particle size diameters similar electrical mobility via rating. This is of great interest technological and commercial, considering the wide variety of products being made available on the market that have in their composition nanoparticles of different chemical compositions. However nanoparticles may offer a potential risk to human health if present in high concentrations in atmospheric air, and the disposition of these should also be cause for study. The classification by electric mobility consists of 4 main parts: the generation of nanoparticles that is where the same are produced (in this work was used as a source of NaCl particles), the charger which gives charge to particles, DMA or electrostatic classifier that performs separation of particles by electrical mobility and particle counter which makes a quantitative analysis of particles present in both output currents DMA. This study was aimed to design and build a Differential Mobility Analyzer low cost and how to assemble the experimental apparatus so that they could perform the classification of nanoparticles. Preliminary results have shown the influence of salt concentration on the amount of nanoparticles present in the aerosol inlet and also the oscillating particle concentration at the input of DMA over a period of a complete test. The results of the testing SMPS (Scanning Mobility Particle Sizer) showed UFSCAR of the particle distribution of Input to 5 concentrations used, and the solutions used in SMPS used to generate the same polydisperse aerosol to be placed in DMA FEQUI/UFU. The results obtained for the monodisperse aerosol stream when compared to balance load distribution proposed for this current, these show a shift to the left, which can be ascribed to some physical parameter is not considered or measurement equipment accurately enough. Adversely to excess current, the balance of load distribution is very experimental results but significant difference in the amount of particles compared to the experimental results, which can also be assigned the same factors mentioned for the monodisperse aerosol stream.