ABSTRACT
Electrospraying and electrospinning are electrohydrodynamic (EHD) techniques that utilize an applied electric field to convert polymer solutions into micro- or nanostructured materials. These approaches are extensively employed in the fabrication of fibers and particles with customizable properties, offering benefits such as high encapsulation efficiency, controlled release mechanisms, and compatibility with heat-sensitive compounds. The production of electrospun fibers and electrosprayed particles necessitates a systematic methodology, involving the careful selection of materials, optimization of processing parameters, and regulation of environmental conditions. A conventional electrospinning setup comprises a high-voltage power supply, a syringe pump containing the polymer solution, and a grounded collector. As the polymer solution is dispensed through a needle at a controlled flow rate, the applied voltage induces the formation of a charged jet. This jet undergoes elongation, solvent evaporation, and subsequent solidification, resulting in continuous fiber formation. The morphology and properties of the fibers are governed by critical parameters, including polymer concentration, flow rate, applied voltage, and the tip-to-collector distance. Conversely, electrospraying operates at lower polymer concentrations, causing jet fragmentation into fine droplets that dry to yield micro- or nanoparticles. The characteristics of the resulting particles are influenced by factors such as solvent properties, surface tension, and electric field strength. Recent advancements in EHD techniques, including co-axial electrospinning, emulsion electrospraying, and melt electrospinning, have significantly enhanced their capabilities. These innovations facilitate precise control over structural and compositional attributes, broadening their applications in drug delivery, food technology, and biomedical engineering. This chapter presents a comprehensive examination of electrospinning and electrospraying methodologies, emphasizing their potential in the development of advanced functional materials.
