Electrospray Drying and Pyrolysis

Electrospray is widely used as the ionization source for mass spectrometry. As a secondary application, it may be used to produce nano droplets and consequently nanoparticles. In this method, a high voltage is applied to a liquid or liquid solution supplied through a capillary. Ideally the liquid reaching the capillary tip forms a Taylor cone, which emits a liquid jet through its apex. Similar to other liquid
jets, the breakup of the electrospray jet leads to the continuous formation of very small and highly charged liquid droplets.
Jaworek and Sobczyk [19] have reviewed and discussed the contribution of electro spraying in the production of nanoparticles, nano-thin films and also Nano encapsulation. In a patent, a method is described for patterning nanostructures using the electrospray technique [20]. In this process, a liquid solution is sprayed out using an electrospray apparatus. When the liquid passes through the spray nozzle, the resulting nano droplets become charged and produce a mist due to the repulsive forces between charged particles.
During the process, the solvent is vaporized forming charged nanoparticles. These particles then adhere to a substrate having the polarity apposite to that of the particles. By changing the voltage, employing a carrier gas, and placing a plate with a hole between the nozzle tip and the substrate, the migration and deposition of nanoparticles may be controlled to produce desired patterns and nanostructures Fig. (4).