Journal of Polymer Research

, 21:607 | Cite as

Structure evolution of electrospun nanofibers probed by in-situ synchrotron X-ray scattering

Original Paper


To characterize the evolution of crystalline structure during heating of electrospun nanofibers is a challenging task due to the fine fiber diameter. In-situ X-ray scattering with synchrotron radiation sources are essentially powerful to trace the subtle structural variation. In this study, aligned syndiotactic polypropylene (sPP) nanofibers with an average diameter of 180 nm were obtained by means of high-temperature electrospinning of an 8 wt.% sPP/ortho-dichlorobenzene solution. The as-spun fibers were characterized to consist of the antichiral form I (11 %), mesophase (27 %) and amorphous phase (62 %), in the absence of isochiral form II. The aligned fibers were subjected to a progressive heating (either stepwisely or continuously at a rate of 4 °C/min) to fiber melting. During heating, structure evolution of the sPP chains was investigated by means of in-situ two-dimensional wide-angle and small-angle X-ray scattering. Upon heating, melting and phase transformation of the mesophase were detected; at 90 °C the processes were completed, giving rise to the annealed fibers of 27 % mixed form I/II and 73 % amorphous phase. In addition to directly producing amorphous phase, heating of the mesophase was accompanied with another two phase transitions, i.e. the solid-solid meso → II phase transition at 50–80 °C, as well as the formation of form I at 80–110 °C. The former is likely due to the chain reorganization in the mesomorphic solid, and the latter is associated with the crystallization of amorphous chains at high temperatures. These events were in accordance with the heating curve obtained from differential scanning calorimetry, which exhibited a small endotherm centered at T 1 for the melting of mesophase, followed by a shallow exotherm centered at T 2 associated with the formation of form I/II crystallites. Both T 1 and T 2 were found to increase with increasing heating rates. However, the melting enthalpy and the double melting temperatures of the sPP nanofibers are relatively independent of the heating rate applied (4 ~ 40 °C/min).


Electrospinning Syndiotactic polypropylene Phase transition 



This work was financially supported by National Science Council of Taiwan (NSC 98-2221-E-006-005-MY3), and National Synchrotron Radiation Research Center (NSRRC, 2009-2-047-5). The assistance of 2-D SAXS and 2-D WAXD experiments from Drs. U-Ser Jeng and Jey-Jau Lee in NSRRC is highly appreciated. This research was, in part, supported by the Ministry of Education, Taiwan, R.O.C. The Aim for the Top University Project to the National Cheng Kung University (NCKU).


  1. 1.
    Rutledge GC, Fridrikh SV (2007) Adv Drug Deliv Rev 59:1384CrossRefGoogle Scholar
  2. 2.
    Greiner A, Wendorff JH (2007) Angew Chem Int Ed 46:5670CrossRefGoogle Scholar
  3. 3.
    Reneker DH, Yarin AL (2008) Polymer 49:2387CrossRefGoogle Scholar
  4. 4.
    Li D, Xia Y (2004) Adv Mater 16:1151CrossRefGoogle Scholar
  5. 5.
    Givens SR, Gardner KH, Rabolt JF, Chase DB (2007) Macromolecules 40:608CrossRefGoogle Scholar
  6. 6.
    Yoshioka T, Dersch R, Tsuji M, Schaper AK (2010) Polymer 51:2383CrossRefGoogle Scholar
  7. 7.
    Rein DM, Shavit-Hadar L, Khalfin RL, Cohen Y, Shuster K, Zussman E (2007) J Polym Sci Polym Phys 45:766CrossRefGoogle Scholar
  8. 8.
    Lee KH, Ohsawa O, Watanabe K, Kim IS, Givens SR, Chase B, Rabolt JF (2009) Macromolecules 42:5215CrossRefGoogle Scholar
  9. 9.
    Watanabe K, Nakamura T, Kim BS, Kim IS (2011) Polym Bull 67:2025CrossRefGoogle Scholar
  10. 10.
    Jao CS, Wang Y, Wang C (2014) Eur Polym J 54:181CrossRefGoogle Scholar
  11. 11.
    Lotz B, Lovinger AJ, Casi RE (1988) Macromolecules 21:2375CrossRefGoogle Scholar
  12. 12.
    Chatani Y, Maruyama H, Asanuma T, Shiomura T (1991) J Polym Sci Polym Phys 29:1649CrossRefGoogle Scholar
  13. 13.
    De Rosa C, Corradini P (1993) Macromolecules 26:5711CrossRefGoogle Scholar
  14. 14.
    Lovinger AJ, Lotz B, Davis DD, Padden FJ (1993) Macromolecules 26:3494CrossRefGoogle Scholar
  15. 15.
    Nakaoki T, Ohira Y, Hayashi H, Horii F (1998) Macromolecules 31:2705CrossRefGoogle Scholar
  16. 16.
    Vittoria V, Guadagno L, Comotti A, Simonutti R, Auriemman F, De Rosa C (2000) Macromolecules 33:6200CrossRefGoogle Scholar
  17. 17.
    De Rosa C, Auriemma F (2006) Prog Polym Sci 31:145CrossRefGoogle Scholar
  18. 18.
    Guadagno L, D’Aniello C, Naddeo C, Vittoria V, Meille SV (2002) Macromolecules 35:3921CrossRefGoogle Scholar
  19. 19.
    Auriemma F, De Rosa C (2003) Macromolecules 36:9396CrossRefGoogle Scholar
  20. 20.
    Wang C, Hsieh TC, Cheng YW (2010) Macromolecules 43:9022CrossRefGoogle Scholar
  21. 21.
    Jeng US, Su CH, Su CJ, Liao KF, Chuang WT, Lai YH, Chang JW, Chen UJ, Huang YS, Lee MT, Yu KL, Lin JM, Liu DG, Chang CF, Liu CY, Chang CH, Liang KS (2010) J Appl Cryst 43:110CrossRefGoogle Scholar
  22. 22.
    De Rosa C, Ruiz De Ballesteros O, Auriemma F, Savarese R (2005) Macromolecules 38:4791CrossRefGoogle Scholar
  23. 23.
    Alexander LE (1969) X-ray diffraction methods in polymer science. Wiley, New York, p 241Google Scholar
  24. 24.
    Baltá-Calleja FJ, Vonk CG (1989) X-ray scattering of synthetic polymers. Elsevier, New York, p 247Google Scholar
  25. 25.
    Liu C, Yu J, He J, Liu W, Sun C, Jing Z (2004) Macromolecules 37:9279CrossRefGoogle Scholar
  26. 26.
    Ohira Y, Horii F, Nakaoki T (2000) Macromolecules 33:5566CrossRefGoogle Scholar
  27. 27.
    Lotz B, Mathieu C, Thierry A, Lovinger AJ, De Rosa C, Ruiz De Ballesteros O, Auriemma F (1998) Macromolecules 31:9253CrossRefGoogle Scholar
  28. 28.
    Grasruck M, Strobl G (2003) Macromolecules 36:86CrossRefGoogle Scholar
  29. 29.
    Rodriguez-Arnold J, Bu Z, Cheng SZD, Hsieh ET, Johnson TW, Geerts RG, Palackal SJ, Hawley GR, Welch MB (1994) Polymer 35:5194CrossRefGoogle Scholar
  30. 30.
    Lacks DJ, Rutledge GC (1995) Macromolecules 28:5789CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  1. 1.Department of Chemical EngineeringNational Cheng Kung UniversityTainanTaiwan

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