Electrospray Aerosol Generator

Generation of liquid aerosols by electrospraying has been a well-studied technique [28,29]. Electrostatic charges are used to decrease the surface tension of a liquid to facilitate or cause breakup of the surface. The placement of charge on the surface in practice necessitates a sufficiently conductive liquid for electric current flow to replenish charge carried away by the aerosol released. In an assist mode, a potential difference is placed on the liquid to decrease the droplet size for pneumatic atomization or vibrating-orifice droplet generation. For an electrostatic spray where a high potential at a liquid surface causes droplets to be ejected, different modes of droplet formation occur where polydisperse or monodisperse droplets are produced. Recent work has shown that with a combination of a constant-pressure feed through a capillary tube and electrospraying, a stable, high-concentration 107cm~3), ultrafine 10 nm) aerosol can be produced [30]. A commercial version of an electrospray aerosol generator is shown in Fig. 5. A small volume of the liquid (conductivity ~ 0.2S/m) to be sprayed is placed in the sample vial. Nonvolatile liquids, solutions, or suspensions of ultrafine particles can be used. Pressurizing the chamber forces a slow flow of the liquid up the capillary tube. A high voltage of several kilo volts applied to the platinum wire causes electrospraying of the liquid surface exiting the capillary tube, producing droplets approximately 200-2000 nm in diameter. The aerosol flow of a few liters per minute consist of highly charged droplets that are neutralized in the ionizer chamber. Careful control of the process parameters result in a monodisperse aerosol.

Was this article helpful?

0 0
Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

Get My Free Ebook

Post a comment