Electrospray

The unique properties of nanoparticles allow us to improve present technologies or to enhance quality of commonly used goods. Unfortunately their mass industrial production is still low profitable, because of several problems:

• coagulation,
• broad particle size distribution,
• changing shape, …

 

The electrospray device can solve the limitation of common industrial devices. The basic principle of electrospraying is based on the fission of the liquid droplets in an electric field (Figure 1). When the high voltage electric field is applied on the conductive liquid droplet, the spherical shape of the droplet is changed into a cone. The cone creates jet on its tip with increasing voltage. The jet emits fine charged droplets. Evaporation of the solvent from the droplets causes charge accumulation, which leads in further dispersion due to "Coulomb repulsions".

Figure 1: Droplet fission caused by Coulomb repulsion.

The electrospaying apparatus (Figure 2) was built by students Jiri Marsalek and Karel Zuček.