A Novel Needle-Less Multi-Pin-‎Electrospinning Method to Fabricate ‎Nanofibers from Dilute PAN Solution

Document Type : Research Paper


1 Department of Polymer Research, Faculty of Petroleum and Chemical Engineering, Razi ‎University, Kermanshah, Iran.‎

2 ‎Department of materials and textile Engineering, College of Engineering, Razi University, ‎Kermanshah, Iran.‎


  A novel needle-less electrospinning system, "Multi-pin-electrospinning" was developed to produce thin nanofibers from dilute Polyacrylonitrile (PAN) solutions. PAN solution was placed in an open polymer bath. 16 stainless steel pins in 4 parallel rows were attached to a metal rod to form stable polymer jets. Pins were dipped into a polymer solution by rotating the pins containing rod and under the application of the electric field, multiple Taylor cone were formed followed by the multi-jet ejection from the cone's tip, then nanofibers were deposited on the aluminum collector sheet placed above the pins. The multi-pin-electrospun nanofibers were thinner with narrower diameter distribution compared with electrospun nanofibers prepared through the conventional method. The influence of the affecting parameters such as solution concentration, applied voltage, pins-collector distance and addition of CaCl2 salt on the diameter of multi-pin-electrospun nanofibers were investigated. The applied voltage change did not significantly affect the average diameter of nanofibers. At pins-collector distance of 6 cm, wet nanofibers with the beaded structure were formed, whereas on increasing the distance bundles in the fibers were disappeared and straight nanofibers with fewer beads were collected. The addition of 1 wt% CaCl2 salt to the 3 wt% PAN/DMF solution resulted in the formation of smooth, almost bead-free nanofibers.


  1. Fang, J., Niu, H., Lin, T., Wang, X., “Applications of electrospun nanofibers”, Chinese Sci. Bull., 53 (2008) 2265-2286.
  2. Silver, F.H., Christiansen, D.L., Snowhill, P.B., Chen, Y., “Transition from viscous to elastic‐based dependency of mechanical properties of self‐assembled type I collagen fibers”, J. Appl. Polym. Sci., 79 (2001) 134-142.
  3. Huang, Z.-M., Zhang, Y.-Z., Kotaki, M., Ramakrishna, S., “A review on polymer nanofibers by electrospinning and their applications in nanocomposites. Composites science and technology”, Compos. Sci. Technol., 63 (2003) 2223-53.
  4. An, M., Xu, H., Lv, Y., Gu, Q., Wang, Z., “Structural difference of gel-spun ultra-high molecular weight polyethylene fibers affected by cold drawing process”, Fiber. Polym., 18 (2017) 549-554.
  5. Martin, C.R., “Membrane-based synthesis of nanomaterials”, Chem. Mater., 8 (1996) 1739-1746.
  6. Dabirian, F., Ravandi, S.H., Pishevar, A., Abuzade, R., “A comparative study of jet formation and nanofiber alignment in electrospinning and electrocentrifugal spinning systems”, J. Electrostat., 69 (2011) 540-546.
  7. Kermanshahi, A.J., Rajabi, L., Dabirian, F., “A solvent degradation approach to expose nanoparticles by decreasing nanofibers' diameter”, Polym. Degrad. Stabil., 138 (2017) 126-132.
  8. Zhang, P., Wang, Q., Zhang, J., Li, G., Wei, Q., “Preparation of amidoxime-modified polyacrylonitrile nanofibers immobilized with laccase for dye degradation”, Fiber. Polym., 15 (2014) 30-34.
  9. Jayaraman, K., Kotaki, M., Zhang, Y., Mo, X., Ramakrishna, S., “Recent advances in polymer nanofibers”, J. Nanosci. Nanotechnol., 4 (2004) 52-65.
  10. Ding, B., Kimura, E., Sato, T., Fujita, S., Shiratori, S., “Fabrication of blend biodegradable nanofibrous nonwoven mats via multi-jet electrospinning”, Polymer, 45 (2004) 1895-19-02.
  11. Wang, X., Niu, H., Lin, T., Wang, X., “Needleless electrospinning of nanofibers with a conical wire coil”, Polym. Eng. Sci., 49 (2009) 1582-1586.
  12. Jirsak, O., Sanetrnik, F., Lukas, D., Kotek, V., Martinova, L., Chaloupek, J., “Method of nanofibres production from a polymer solution using electrostatic spinning and a device for carrying out the method”, Google Patents, (2009)..
  13. Petrik, S., Maly, M., “Production nozzle-less electrospinning nanofiber technology, in:  MRS Proceedings”, Cambridge Univ Press, (2009) 79-90.
  14. Yarin, A., Zussman, E., “Upward needleless electrospinning of multiple nanofibers”, Polymer, 45 (2004) 2977-2980.
  15. Niu, H., Lin, T., Wang, X., “A comparison of cylinder and disk nozzles”, J. Appl. Polym. Sci., 114 (2009) 3524-3530.
  16. Liu, Z., Chen, R., He, J., “Active generation of multiple jets for producing nanofibres with high quality and high throughput”, Mater. Design, 94 (2016) 496-501.
  17. Bergshoef, M.M., Vancso, G.J., “Transparent nanocomposites with ultrathin, electrospun nylon‐4, 6 fiber reinforcement”, Adv. Mater., 11 (1999) 1362-1365.
  18. Xu, C., Yang, F., Wang, S., Ramakrishna, S., “In vitro study of human vascular endothelial cell function on materials with various surface roughness”, J. Biomed. Mater. Res. A, 71 (2004) 154-161.
  19. Derch, R., Greiner, A., Wendorff, J., “Dekker encyclopedia of nanoscience and nanotechnology, CRC, New York, (2004).
  20. Mit‐uppatham, C., Nithitanakul, M., Supaphol, P., “Ultrafine electrospun polyamide‐6 fibers: effect of solution conditions on morphology and average fiber diameter”, Macromol. Chem. Phys., 205 (2004) 2327-2338.
  21. Baumgarten, P.K., “Electrostatic spinning of acrylic microfibers”, ‎J. Colloid. Interface. Sci., 36 (1971) 71-79.
  22. Moradipour, P., Dabirian, F., Rajabi, L., Derakhshan, A.A., “Fabrication and characterization of new bulky layer mixed metal oxide ceramic nanofibers through two nozzle electrospinning method”, Ceram. Int., 42 (2016) 13449-13458.
  23. Cengiz-Çalliolu, F., Jirsak, O., Dayik, M., “Electric current in polymer solution jet and spinnability in the needleless electrospinning process”, Fiber. Polym., 13 (2012) 1266-1271.
  24. Kenawy, E.-R., Layman, J.M., Watkins, J.R., Bowlin, G.L., Matthews, J.A., Simpson, D.G., Wnek, G.E., “Electrospinning of poly (ethylene-co-vinyl alcohol) fibers”,  Biomaterials, 24 (2003) 907-913.
  25. Jalili, R., Morshed, M., Ravandi, S.A.H., “Fundamental parameters affecting electrospinning of PAN nanofibers as uniaxially aligned fibers”, J. Appl. Polym. Sci., 101 (2006) 4350-4357.
  26. Schoenmaker, B. De, Schueren, L. Van der, Ceylan, Ö., Clerck, K. De, “Electrospun polyamide 4.6 nanofibrous nonwovens: parameter study and characterization”, J. Nanomater., 2012 (2012) 14.
  27. Miyoshi, T., Toyohara, K., Minematsu, H., “Preparation of ultrafine fibrous zein membranes via electrospinning”, Polym. Int., 54 (2005) 1187-1190.
  28. Mo, X., Xu, C., Kotaki, M., Ramakrishna, S., “Electrospun P (LLA-CL) nanofiber: a biomimetic extracellular matrix for smooth muscle cell and endothelial cell proliferation”, Biomaterials, 25 (2004) 1883-1890.
  29. Deitzel, J.M., Kleinmeyer, J., Harris, D., Tan, N.B., “The effect of processing variables on the morphology of electrospun nanofibers and textiles”, Polymer, 42 (2001) 261-272.
  30. Gu, S., Ren, J., Vancso, G., “Process optimization and empirical modeling for electrospun polyacrylonitrile (PAN) nanofiber precursor of carbon nanofibers”, Eur. Polym. J., 41 (2005) 2559-2568.
  31. Ramakrishna, S., “An introduction to electrospinning and nanofibers”, World Scientific, (2005).
  32. Doustgani, A., Vasheghani-Farahani, E., Soleimani, M., Hashemi-Najafabadi, S., “Preparation and characterization of aligned and random nanofibrous nanocomposite scaffolds of poly (vinyl alcohol), poly (e-Caprolactone) and nanohydroxyapatite”, Int. J. Nanosci. Nanotechnol, 7 (2011) 127-132.
  33. Qin, X.H., Yang, E.L., Li, N., Wang, S.Y., “Effect of different salts on electrospinning of polyacrylonitrile (PAN) polymer solution”, J. Appl. Polym. Sci., 103 (2018) 3865-3870.
  34. He, C.H., Liu, P., Liu, H.Y., “Effect of concentration of metal inorganic salt on fiber diameter in electrospinning process: mathematical model and experimental verification”, Therm. Sci., 22 (2018) 2565-2570.