In this study, Nafion® NR 40 beads with polyethylene oxide (PEO) are fabricated into a nanofiber membrane using electrospinning. In particular, Nafion® beads in non-toxic mixed solvent (EtOH and H2O) were blended with the carrier polymer PEO, which is the minor component in the solution responsible for the solution spinnability. The highest content of Nafion® in the nanofiber is 98.04%. To investigate the factors influencing the nanofiber diameter during electrospinning, an orthogonal design method was adopted. These factors include the carrier polymer content, distance between the syringe needle and roller collector, flow rate of the electrospinning solution, and the roller rotation speed. After obtaining the significant factors and optimal test level, an additional optimization experiment is conducted under the best conditions. The resulting nanofibers have a diameter of ∼150 nm. Moreover, the obtained Nafion® nanofiber membrane has strong potential for applications in polymer electrolyte membrane fuel cells (PEMFC), the chlor-alkali industry, catalysts, and metal ion removal. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41755.
Through orthogonal experimental methods, the melt electrospinning of pure phenolic fibers has been achieved. The preparation is based on an orthogonal experimental method, which was designed to investigate the optimal conditions for production through integrated effects of spinning temperature, gap between spinneret and collector, as well as applied voltage. We found that optimal spinning conditions at 160°C, a spinneret-to-collector gap of 8 cm, and applied voltage at 40 kV produce an average electrospun fiber diameter reaching 4.44 ± 0.76 μm, with narrow variance distribution. The fibers were cured in a solution with 18.5% formaldehyde and 12% hydrochloric acid, heated from room temperature to 80°C and maintained 1h. In this report, the morphology, structural changes, and heat resistance of the fibers are characterized. Obtained results reveal that curing the fiber reduces crystallization and improves heat resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42574.
Electrospinning is an efficient and direct method of fabricating nanofibers. Fibers are frequently unstable in the electrospinning process, and the uneven distribution of the electric field is an important factor leading to instability. Experimental and finite element simulation studies are conducted on the process of melt electrospinning in a parallel electric field. Two parallel metal disks are used to successfully generate a uniform electric field. Electric field intensity on the edges of the metal disk is always stronger than the field at the center of the disk or at the spinneret bottom. The diameters, distances, and relative areas of these disks significantly affect the distribution of the electric field. Thus, the parallel electric field effectively reduces jet buckling in melt electrospinning. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 946–952
Melt electrospinning is a much simpler and safer method in the production of ultra-fine fibers compared with solution electrospinning. However, high-spinning temperature usually leads to serious degradation of polymer materials. In determining factors that affect the relative molecular mass of polylactic acid (PLA) fibers during melt electrospinning, an orthogonal design method was used to examine the influence of melting temperature, spinning distance, and species and content of antioxidants. Results showed that antioxidant content at the present three levels (i.e., 0.1%, 0.3%, and 0.5%) has the most considerable effect on the relative molecular mass of PLA fibers. Error analysis showed that changes in temperature, distance, and antioxidant content influence the experiment's results significantly. All interaction effects were larger than those of the single factor in the experimental results. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Melt electrospinning is a much more simple and safe method to produce ultra fine fibers than solution electrospinning. The diameters of melt electrospinning fibers are thicker. To find the factors that affect the fibers diameter in melt electrospinning, orthogonal design was used to examine melt temperature, spinning voltage, spinning distance, and melt flow rate (MFR) of polymer. Results showed that MFR at present three levels has the most important impact both on the average diameters and standard deviations of fiber diameters. The scanning electron microscopy pictures show that all the fibers have smooth surface, which means the melt electrospinning fibers have good mechanical properties. POLYM. ENG. SCI., 50:2074–2078, 2010. © 2010 Society of Plastics Engineers
The impacts of Rouse spring, Fraenkel spring, and one kind of finitely extensible nonlinear elastic spring (FENE-PM spring) on the surface tension-induced retraction of a polymer ellipsoid in a matrix were compared using dissipative particle dynamics. Using the same spring constant, obvious differences among the three kinds of springs were found. A fast retraction process was observed from the hard Fraenkel spring, a slow process from the soft Rouse spring, and an intermediate process from the FENE-PM spring. The effects of varying the spring constant and the chain length were also investigated. The results indicate that the influence of increasing spring hardness for a given spring type was significant; whereas, the influence of chain length was minor after five bonds were reached. The effects of varying the FENE-PM rm parameter were also studied to provide a reliable value for this study. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010