Preparation and Characterization of PSF Membranes by Phosphoric Acid and 2-Butoxyethanol

인산 및 2-부톡시에탄올 첨가에 의한 PSF 고분자 분리막의 제조 및 특성

  • Kim, Nowon (Department of Environmental Engineering, Dong-Eui University)
  • Received : 2012.06.05
  • Accepted : 2012.06.21
  • Published : 2012.06.29

Abstract

Flat sheet membranes were prepared with polysulfone (PSF) by an immersion precipitation phase inversion method. Membranes were prepared with PSF/N-methylpyrrolidone (NMP)/polyvinylpyrrolidone (PVP)/phosphoric acid casting solution and water coagulant. By using the successive process of the vapor-induced phase inversion (VIPS) followed by the nonsolvent-induced phase inversion (NIPS), the effect of phosphoric acid addition to casting solution on morphology and permeability of membrane was studied. The mean pore size, the porosity, and the water flux of membranes were increased by the addition of small amount of phosphoric acid. Furthermore, the morphology of the prepared membranes were changed from a dense sponge-like structure to highly enhanced asymmetric structure. PSF/NMP/PVP/phosphoric acid/2-butoxyethanol (BE) casting solution were prepared and cast the successive VIPS-NIPS process with same experimental condition. Due to the addition of BE to casting solution, the mean pore size and almost 0.1 ${\mu}m$ and the water flux increased about 10 to 12 $L/cm^2{\cdot}min{\cdot}bar$.

침지법 상전이 공정 방법으로 polysulfone (PSF) 분리막을 제조하였다. PSF/NMP/PVP/phosphoric acid의 캐스팅 용액과 물 침전조를 이용하여 분리막을 제조하였다. 증기 유도 상전이법과 비용매 유도 상전이법을 연속하여 적용함으로서 캐스팅 용액에 첨가된 인산의 영향이 분리막의 구조 및 투과량에 미치는 영향을 살펴보았다. 미량의 인산의 첨가로도 평균 기공의 크기, 공극률, 수투과량의 증가를 볼 수 있었다. 또한 분리막의 구조가 치밀한 스펀지 형태의 구조에서 비대칭성이 향상된 구조로 변화함을 확인할 수 있었다. PSF/NMP/PVP/phosphoric acid/BE를 함유한 캐스팅 용액을 준비한 후 동일한 조건으로 증기 유도 상전이법과 비용매 유도 상전이법을 연속하여 적용하여 분리막을 제조하였다. BE의 첨가는 평균 기공의 크기를 거의 0.1 ${\mu}m$ 정도 향상시키는 효과를 가져왔으며 수 투과 유량 또한 10~12 $L/cm^2{\cdot}min{\cdot}bar$ 향상시키는 결과를 나타내었다.

Keywords

Acknowledgement

Supported by : 동의대학교

References

  1. M. C. Porter, "Handbook of industrial membrane technology", pp. 61-62, Noyes Publications, Park Ridge, New Jersey (1990).
  2. D. H. Lee, L. H. Kim, and K. Y. Chung, "Wastewater recycling from electroless printed circuit board planting process using membranes", Membrane Journal, 13, 1/9 (2003).
  3. D. B. Mosqueda-Jimenez, R. M. Narbaitz, T. Matsuura, G. Chowdhury, G. Pleizier, and J. P. Santerre, "Influence of processing conditions on the properties of ultrafiltration membranes", J. Membr. Sci., 231, 209 (2004). https://doi.org/10.1016/j.memsci.2003.11.026
  4. M. Mulder, "Basic Principles of Membrane Technology", pp. 71-89, Kluwer Academic Publishers, London (1996).
  5. P. van de Witte, P. J. Dijkstra, J. W. A. van den Berg, and J. Feijen, "Phase separation processes in polymer solutions in relation to membrane formation", J. Membr. Sci., 117, 1 (1996). https://doi.org/10.1016/0376-7388(96)00088-9
  6. R. M. Boom, I. M. Wienk, Th. Van den Boomgaard, and C.A. Smolders, "Microstructures in phase inversion membranes. Part 2. The role of a polymeric additive", J. Membr. Sci., 73, 277 (1992). https://doi.org/10.1016/0376-7388(92)80135-7
  7. I. M. Wienk, R. M. Boom, M. A. M. Beerlage, A. M. W. Bulte, and C. A. Smolders, "Recent advances in the formation of phase inversion membranes made from amorphous or semi-crystalline polymers", J. Membr. Sci., 113, 361 (1996). https://doi.org/10.1016/0376-7388(95)00256-1
  8. D. B. Mosqueda-Jimenez, R. M. Narbaitz, T. Matsuura, G. Chowdhury, G. Pleizier, and J. P. Santerre, "Influence of processing conditions on the properties of ultrafiltration membranes", J. Membr. Sci., 231, 209 (2004). https://doi.org/10.1016/j.memsci.2003.11.026
  9. S.-J. Shin, J.-P. Kim, H.-J. Kim, J.-H. Jeon, and B.-R. Min, "Preparation and characterization of polyethersulfone microfiltration membranes by a 2-methoxyethanol additive", Desalination, 186, 1 (2005). https://doi.org/10.1016/j.desal.2005.03.092
  10. C. Stropnik and V. Kaiser, "Polymeric membranes preparation by wet phase separation: mechanisms and elementary processes", Desalination, 145, 1 (2002). https://doi.org/10.1016/S0011-9164(02)00322-3
  11. R. M. Boom, T. van den Boomgard, and C. A. Smolders, "Mass transfer and thermodynamics during immersion precipitation for a two-polymer system: evaluation with the system PES-PVP-NMPwater", J. Membr. Sci., 90, 231 (1994). https://doi.org/10.1016/0376-7388(94)80074-X
  12. D. Rana, T. Matsuura, R. M. Narbaitz, and C. Feng, "Development and characterization of novel hydrophilic surface modifying macromolecule for polymeric membranes", J. Membr. Sci., 249, 103 (2005). https://doi.org/10.1016/j.memsci.2004.09.034
  13. V. P. Khare, A. R. Greenberg, and W. B. Krantz, "Vapor-induced phase separation-effect of the humid air exposure step on membrane morphology: Part I. Insights from mathematical modeling", J. Membr. Sci., 258, 140 (2005). https://doi.org/10.1016/j.memsci.2005.03.015
  14. M.-J. Han, "Effect of propionic acid in the casting solution on the characteristics of phase inversion polysulfone membranes", Desalination, 121, 31 (1999). https://doi.org/10.1016/S0011-9164(99)00005-3
  15. D. M. Koenhen and C. A. Smolders, "The determination of solubility parameters of solvents and polymers by means of correlations with other physical quantities", J. Appl. Polym. Sci., 19, 1163 (1975). https://doi.org/10.1002/app.1975.070190423
  16. http://www.sigmaaldrich.com/content/dam/sigma-aldrich/ docs/Aldrich/General_Information/polymer_solutions.pdf, June 4 (2012).
  17. S.-R. Choi, S.-J. Park, B.-K. Seo, K. W. Lee, S. T. Nam, and M.-J. Han, "Effect of propionic acid additive on preparation of phase inversion polysulfone membrane", Membrane Journal, 18, 4, 261 (2008).
  18. B. G. Park, S.-H. Kong, and S. Y. Nam, "Phase behavior and morphological studies of polysulfone membranes ; the effect of alcohols used as a nonsolvent coagulant", Membrane Journal, 12, 4, 255 (2005).
  19. N. Kim, "Preparation and characteristics of polyethersulfone microfiltration membranes", Membrane Journal, 17, 329 (2007)
  20. W. Wilson, K. Gupta, A. Jena, R. Webber, M. Connoly, E. Mayer, B. V. Ramarao, and C. Dryer, "Advanced technique for pore structure characterization theory & practices : PMI Short Course June 2004", PMI, New York (2004).
  21. Y. Son and N. Kim, "Effect of polymer structure on membrane morphology by addition of 2-butoxyethanol," Membrane Journal, 21, 307 (2011).