Hsu-Hsien Chang1,2, Sheng-Chang Chen1,2 and Liao-Ping Cheng This email address is being protected from spambots. You need JavaScript enabled to view it.1,3

1Department of Chemical and Materials Engineering, Tamkang University, Tamsui, Taiwan 251, R.O.C.
2Bright Sheland International Co., New Taipei City, Taiwan 221, R.O.C.
3Energy and Opto-Electronic Materials Research Center, Tamkang University, Tamsui, Taiwan 251, R.O.C.


 

Received: March 9, 2017
Accepted: July 30, 2017
Publication Date: March 1, 2018

Download Citation: ||https://doi.org/10.6180/jase.201803_21(1).0011  

ABSTRACT


Hollow fiber membranes of PVDF were prepared by isothermal wet spinning process from the water/DMF/PVDF system at 25 C. The dope solution comprised 21 wt% PVDF in DMF, and pure water was employed both as the inner and outer coagulants. SEM imaging of the membrane indicated an unexpected interesting morphology: columnar macrovoids extended from the outer surface to the central region, while cellular pores constituted the inner half of the membrane. As water was a harsh nonsolvent, one tended to think that macrovoids shall form towards the inner surface of the hollow fiber. Absence of macrovoids in this region was explained based on the fact that DMF would accumulate rapidly in the inner extruding stream as it underwent mass-exchange with water in the inner bath. Such activity rendered effectively the coagulant became effectively a soft one. As a result, macrovoids was eliminated and the inner surface became porous.


Keywords: PVDF, Hollow Fiber, Membrane, Morphology, NIPS


REFERENCES


  1. [1] Strathmann, H., Introduction to Membrane Science and Technology, Wiley-VCH Verlag & Co., Germany (2011).
  2. [2] Mulder, M., Basic Principles of Membrane Technology,2 nd ed., Kluwer Academic Publisher, Dordrecht (1996).
  3. [3] Culfaz, P. Z., Rolevink, E., Rijn, C. V., Lammertink,R. G. H. and Wessling, M., “Microstructured Hollow Fibers for Ultrafiltration,” Journal of Membrane Science, Vol. 347, No. 12, pp. 32–41 (2010). doi: 10. 1016/j.memsci.2009.10.003
  4. [4] Peng, N., Widjojo, N., Sukitpaneenit, M. M., Teoh, P., Lipscomb, G. G., Chung, T. S. and Lai, J. Y., “Evolution of Polymeric Hollow Fibers as Sustainable Technologies: Past, Present, and Future,” Progress in Polymer Science, Vol. 37, No. 10, pp. 1401–1424 (2012). doi: 10.1016/j.progpolymsci.2012.01.001
  5. [5] Liu, F., Hashim, N. A., Liu, Y., Abed, M. R. M. and Li, K., “Review-progress in the Production and Modification of PVDF Membranes,” Journal of Membrane Science, Vol. 375, No. 1-2, pp. 1-27 (2011). doi: 10.1016/j.memsci.2011.03.014
  6. [6] Kang, G. D. and Cao, Y. M., “Application and Modification of Poly(vinylidene fluoride) (PVDF) Membranes – A Review,” Journal of Membrane Science, Vol. 463, No. 1, pp. 145165 (2014). doi: 10.1016/ j.memsci.2014.03.055
  7. [7] Drioli, E., Ali, A., Simone, S., Macedonio, F., Al-Jiil, S. A., Shabonah, F. S., Al-Romaih,H. S., Al-Harbi, O., Figoli, A. and Criscuoli, A., “Novel PVDF Hollow Fiber Membranes for Vacuum and Direct Contact Membrane Distillation Applications,” Separation and Purification Technology, Vol. 115, No. 30, pp. 2738 (2013). doi: 10.1016/j.seppur.2013.04.040
  8. [8] Bottino, A., Camera,G. R., Capannelli, G. and Munari, S., “The Formation of Microporous Polyvinylidene Difluoride Membranes by Phase Separation,” Journal of Membrane Science, Vol. 577, No. 1, pp. 120 (1991). doi: 10.1016/S0376-7388(00)81159-X
  9. [9] Lin, D. J., Lin, C. L. and Guo, S. Y., “Network Nano-porous Poly(vinylidene fluoride-co-hexafluoropropene) Membranes by Nano-gelation Assisted Phase Separation of Poly(vinylidene fluoride-co-hexafluoropropene)/Poly(methyl methacrylate) Blend Precursor in Toluene,” Macromolecules, Vol. 45, No. 21, pp. 88248832 (2012). doi: 10.1021/ma301075e
  10. [10] Xu, J. and Xu, Z. L., “Poly(vinyl chloride) (PVC) Hollow Fiber Ultrafiltration Membranes Prepared from PVC/additives/solvent,” Journal of Membrane Science, Vol. 208, No. 12, pp. 203212 (2002). doi: 10.1016/S0376-7388(02)00261-2
  11. [11] Cheng, L. P., “Effect of Temperature on the Formation of Microporous PVDF Membranes by Precipitation from 1-Octanol/DMF/PVDF and Water/DMF/PVDF Systems,” Macromolecules, Vol. 32, No. 20, pp. 66686674 (1999). doi: 10.1021/ma990418l
  12. [12] Sukitpaneenit, P. and Chung, T. S., “Molecular Elucidation of Morphology and Mechanical Properties of PVDF Hollow Fiber Membranes from Aspects of Phase Inversion, Crystallization and Rheology,” Journal of Membrane Science, Vol. 340, No. 12, pp. 192205 (2009). doi: 10.1016/j.memsci.2009.05.029
  13. [13] Ansorge, W., Schuster, O., Wechs, F. and Dombrowski, K., U.S. Patent 8,727,136 B2 (2014).
  14. [14] Setiawan, L., Wang, R., Li, K. and Fane, A. G., “Fabrication and Characterization of Forward Osmosis Hollow Fiber Membranes with Antifouling NF-like Selective Layer,” Journal of Membrane Science, Vol. 394 395, No. 15, pp. 8088 (2012). doi: 10.1016/j.memsci. 2011.12.026
  15. [15] Gryta, M. and Barancewicz, M., “Influence of Morphology of PVDF Capillary Membranes on the Performance of Direct Contact Membrane Distillation,” Journal of Membrane Science, Vol. 358, No. 12, pp. 158167 (2010). doi: 10.1016/j.memsci.2010. 04.044
  16. [16] Shih, C. H., Gryte, C. C. and Cheng, L. P., “Precipitation Dynamics for the Formation of Nylon-6 Polyamide Membranes by Isothermal Precipitation in Water/Formic Acid Solutions,” Journal of Applied Science and Engineering, Vol, 15, No. 4, pp. 357366 (2012). doi: 10.6180/jase.2012.15.4.06
  17. [17] Lin, D. J., Chang, C. L., Chen, T. C. and Cheng, L. P., “On the Structure of Porous Poly(vinylidene fluoride) Membrane Prepared by Phase Inversion from WaterNMP-PVDF System,” Tamkang Journal of Science and Engineering, Vol. 5, No. 2, pp. 9598 (2002). doi: 10.6180/jase.2002.5.2.04
  18. [18] Lin, D. J., Beltsios, K., Chang, C. L. and Cheng, L. P., “Fine Structure and Formation Mechanism of Particulate Phase-inversion Poly(vinylidene fluoride) Membranes,” Journal of Polymer Science Part B Polymer Physics, Vol. 41, No. 13, pp. 15781588 (2003). doi: 10.1002/polb.10513
  19. [19] Kuo, C. Y., Lin, H. N., Tsai, H. A., Wang, D. M. and Lai, J. Y., “Fabrication of a High Hydrophobic PVDF Membrane via Nonsolvent Induced Phase Separation,” Desalination, Vol. 233, No. 13, pp. 4047 (2008). doi: 10.1016/j.desal.2007.09.025
  20. [20] Chang, H. H., Chen, S. C., Lin, D. J. and Cheng, L. P., “Preparation of Bi-continuous Nylon-66 Porous Membranes by Coagulation of Incipient Dopes in Soft Non-solvent Baths,” Desalination, Vol. 313, No. 15, pp. 7786 (2013). doi: 10.1016/j.desal.2012.12.009
  21. [21] Buonomenna, M. G., Macchi, P., Davoli, M. and Drioli, E., “Poly(vinylidene fluoride) Membranes by Phase Inversion: the Role the Casting and Coagulation Conditions Play in Their Morphology, Crystalline Structure and Properties,” European Polymer Journal, Vol. 43, No. 4, pp. 15571572 (2007). doi: 10.1016/j.eurpolymj.2006.12.033
  22. [22] Young, T.H., Lin, C.W., Cheng, L.P.and Hsieh, C.C., “Preparation of EVAL Membranes with Smooth and Particulate Morphologies for Neuronal Culture,” Biomaterials, Vol. 22, No. 13, pp. 17711777 (2001). doi: 10.1016/S0142-9612(00)00337-9
  23. [23] Chang, H. H., Chang, L. K., Yang, C. D., Lin, D. J. and Cheng, L. P., “Effect of Polar Rotation on the Formation of Porous Poly(vinylidene fluoride) Membranes by Immersion Precipitation in an Alcohol Bath,” Journal of Membrane Science, Vol. 513, No. 1, pp. 186196 (2016). doi: 10.1016/j.memsci.2016. 04.052
  24. [24] Chang, H. H., Chen, S. C., Lin, D. J. and Cheng, L. P., “The Effect of Tween-20 Additive on the Morphology and Performance of PVDF Membranes,” Journal of Membrane Science, Vol. 466, No. 15, pp. 302312 (2014). doi: 10.1016/j.memsci.2014.05.011
  25. [25] Lin, D. J., Chang, C. L., Huang, F. M. and Cheng, L. P., “Effect of Salt Additive on the Formation of Microporous Poly(vinylidene fluoride) Membranes by Phase Inversion From LiClO4/Water/DMF/PVDF System,” Polymer, Vol. 44, No. 2, pp. 413422 (2003). doi: 10.1016/S0032-3861(02)00731-0
  26. [26] Smolders, C. A., Reuvers, A. J., Boom, R. M. and Wienk, I. M., “Microstructures in Phase-inversion Membranes. Part 1: Formation of Macrovoids,” Journal of Membrane Science, Vol. 73, No. 23, pp. 259 275 (1992). doi: 10.1016/0376-7388(92)80134-6
  27. [27] Strathmann, H., in Lloyd DR (editor), “Material Science of Synthetic Membrane,” ACS Symposium Series, Washington, DC: American Chemical Society, pp. 165195 (1985).
  28. [28] McKelvey, S. A. and Koros, W. J., “Phase Separation, Vitrification, and the Manifestation of Macrovoids in Polymeric Asymmetric Membranes,”Journal of Membrane Science, Vol. 112, No. 1, pp. 2939 (1996). doi: 10.1016/0376-7388(95)00197-2
  29. [29] Ray, R. J., Krantz, W. B. and Sani, R. L., “Linear Stability Theory Model for Finger Formation in Asymmetric Membranes,” Journal of Membrane Science, Vol. 23, No. 2, pp. 155182 (1985). doi: 10.1016/ S0376-7388(00)82216-4
  30. [30] Termonia, Y., “Fundamentals of Polymer Coagulation,” Journal of Polymer Science Part B Polymer Physics, Vol. 33, No. 2, pp. 279288 (1995). doi: 10.1002/polb.1995.090330213
  31. [31] Lai, J. Y., Lin, F. C., Wu, T. T. and Wang, D. M., “On the Formation of Macrovoids in PMMAMembranes,” Journal of Membrane Science, Vol. 155, No. 1, pp.3143 (1999). doi: 10.1016/S0376-7388(98)00292-0


Latest Articles