ABSTRACT
Electrospinning occurs when a polymer solution or melt is charged to high voltage to produce fibers. Voltages of 5 kV to 30 kV are sufficient to overcome surface tension forces of the polymer, and a free surface of charged polymer will produce fine jets of liquid that are rapidly drawn toward a grounded target. Nanofiber spray coatings were applied directly to the foam, and aerosol particle filtration and air flow properties were measured as a function of deposition thickness. The challenge is to develop a density gradient through the coating thickness, as well as intermingling fibers of different compositions together into the web. Electrospun fibrous membranes are porous materials. The porosity, pore structure, and pore size determine most of the transport properties we are interested in for these materials. Patterning may enhance the strength of electrospun layers. Fibers deposit preferentially over conductive regions and also tend to align themselves with the underlying wire pattern.
