Electrospinning of poly(methyl methacrylate) nanofibers in a pump-free process

The effects of processing parameters, includ- ing solution concentration, viscosity, nozzle diameter, voltage bias and the nozzle to collector distance, on the morpho logy and diameters of poly(methyl methacrylate) (PMMA) fibers have been systematically investigated, using a unique pump-free electrospinning method. For PMMA solution concentrations less than the criti- cal entanglement concentration, c e , prolate spheroid- shaped droplets or beads with fibers were formed, whereas at concentrations above c e , good quality bead- free fibers were formed. Quantitative analysis revealed a linear dependence between the solution viscosity and fiber diameter. Larger fiber diameters were achieved by increasing the nozzle diameter and voltage bias. Increas- ing the bias voltage has the additional effect of broaden- ing the diameter distribution, as a result of splaying and splitting. By contrast, when the strength of the electrical field was reduced by increasing the distance between the nozzle and collector, the overall fiber dia meter was reduced.