Production of Homogeneous Particles by Controlled Neutralization of Electrosprays

Identifier:  TDX:3653

Handle: https://hdl.handle.net/20.500.11797/TDX3653

Authors:  Carrasco Muñoz, Antonio Jesús

Abstract:
This thesis is focused on the efficient reduction of charge of electrospray droplets to produce homogeneously sized polymer particles by electrospraying a polymer solution. In the electrospraying process, a steady micro-jet is emitted, from the tip of the so-called Taylor cone, breaking up into highly charged tiny droplets. When using a polymercontaining solution, it results in narrowly dispersed particle sizes, from micrometer to nanometer scale, depending on liquid properties and operating conditions. Therefore, electrospray is gaining research interest in different fields such as pharmaceutics. Among its advantages over other liquid atomization methods includes its ability to produce much smaller particles (in the few-microns and nano-metric size ranges) with size homogeneity and high energy efficiency. But the high charge induced on the droplets by this technique may distort the size uniformity. This occurs if the droplet undergoes a Coulombic instability. After that, the created polymer particle loses its shape and size. An electrospray-neutralization setup has been developed in which the droplet charge was reduced significantly, preventing Coulombic instabilities, and being able to generate homogeneous polymer particles in a controlled atmosphere conditions, obtaining the desired particle morphology, and preventing filamentous particles