Membrane Journal (멤브레인)

The Membrane Society of Korea (한국막학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Seed Coating Layer on the Microstructure of NaA Zeolite Separation Layer Grown on ${\alpha}$-alumina Support

종결정 코팅층이 다공성 ${\alpha}$-알루미나 지지체 표면에 성장되는 NaA 제올라이트 분리층의 미세구조에 미치는 영향

  • Kim, Min-Ji (Department of Energy Science and Technology, Graduate School of Energy Science and Technology(GEST), Chungnam National University) ;
  • Sharma, Pankaj (Department of Energy Science and Technology, Graduate School of Energy Science and Technology(GEST), Chungnam National University) ;
  • Han, Moon-Hee (Department of Energy Science and Technology, Graduate School of Energy Science and Technology(GEST), Chungnam National University) ;
  • Cho, Churl-Hee (Department of Energy Science and Technology, Graduate School of Energy Science and Technology(GEST), Chungnam National University)
  • 김민지 (충남대학교 에너지과학기술대학원 에너지과학기술학과) ;
  • ;
  • 한문희 (충남대학교 에너지과학기술대학원 에너지과학기술학과) ;
  • 조철희 (충남대학교 에너지과학기술대학원 에너지과학기술학과)
  • Received : 2014.09.24
  • Accepted : 2014.10.01
  • Published : 2014.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

NaA zeolite/${\alpha}$-alumina composite membranes were hydrothermally synthesized at $100^{\circ}C$ for 24 hr by using nanosize seed of 100 nm in diameter and an ${\alpha}$-alumina support of $0.1{\mu}m$ in pore diameter, and then effect of seed coating layer on the microstructure of NaA zeolite separation layer was systematically investigated. In cases when nanosize seed was coated with a monolayer, increment in seed coverage induced small grained and thick NaA zeolite separation layer. On the other hand, in case when nanosize seed was coated with a multilayer, much small grained and thick separation layer was formed. It was clear that an uniform monolayer seed coating is required to grow hydrothermally a thin and defect-free NaA zeolite separation layer. In the present study, it was clearly announced that seed coating layer is a key factor to determine the microstructure of NaA zeolite layer, secondary grown on a porous support.

본 연구에서는 종결정 코팅층이 NaA 제올라이트 분리막 형성에 미치는 영향에 대하여 고찰하였다. NaA 제올라이트 분리막은 평균입경 100 nm 종결정을 다공성 ${\alpha}$-알루미나 표면에 진공여과 코팅하고 $100^{\circ}C$에서 24시간 수열처리하여 합성되었다. 이때 지지체 표면에 분포된 종결정 양을 조절한 후 형성된 NaA 제올라이트 분리층의 두께와 결정입 크기 등 미세구조에 미치는 영향에 대하여 고찰하였다. 종결정 코팅 양은 지지체를 통과한 종결정 수용액의 여과 양을 조절하여 제어하였다. 종결정을 단일층으로 코팅한 후 합성하였을 경우, 코팅 양이 증가함에 따라 분리층 단면에서의 두께와 균일도는 증가하였으며, 표면에서의 결정입 크기는 감소하면서 균일도는 증가하였다. 반면, 종결정을 다층으로 코팅한 후 합성하였을 경우, 균일한 분리층을 형성하였지만 단일층으로 코팅된 경우에 비하여 불균일하였으며 두꺼운 분리층이 형성되었다. 균일하고 초박형의 결함이 없는 제올라이트 분리층을 형성하기 위해서는 종결정을 균일하고 단일층으로 코팅하여야 함을 알 수 있었다. 본 연구로부터 종결정의 코팅 상태가 이차성장에 의한 NaA 제올라이트 분리층의 미세구조를 결정하는 중요한 인자임을 확인할 수 있었다.

Keywords

References

  1. Y. Yan, M. E. Davis, and G. R. Gavalas, "Preparation of highly selective zeolite ZSM-5 membranes by a post-synthetic coking treatment", J. Membr. Sci., 123, 95 (1997). https://doi.org/10.1016/S0376-7388(96)00206-2
  2. Q. Liu, R. Noble, J. L. Falconer, and H. Funke, "Organics/water separation by pervaporation with a zeolite membrane", J. Membr. Sci., 117, 163 (1996). https://doi.org/10.1016/0376-7388(96)00058-0
  3. Y. Yan and T. Bein, "Zeolite thin films with tunable molecular sieve function", J. Am. Chem. Soc., 117, 9990 (1995). https://doi.org/10.1021/ja00145a008
  4. M. Nomura, T. Yamaguchi, and S. I. Nakao, "Silicalite membranes modified by counter diffusion CVD technique", Ind. Eng. Chem. Res., 36, 4217 (1997). https://doi.org/10.1021/ie970338a
  5. S. J. Jeong, J. G. Yeo, M. H. Han, and C. H. Cho, "A study on permeation of $CO_2-N_2-O_2$ mixed gases through a NaY zeolite membrane under permeate evacuation mode", Membrane Journal, 23, 343 (2013).
  6. H. Kita, K. Horii, Y. Ohtoshi, K. Tanaka, and K. I. Okamoto, "Synthesis of a zeolite NaA membrane for pervaporation of water/organic liquid mixtures", J. Mater. Sci. Lett., 14, 206 (1995). https://doi.org/10.1007/BF00318258
  7. L. C. Boudreau and M. Tsapatsis, "A highly oriented thin film of zeolite A", Chem. Mater., 9, 1705 (1997). https://doi.org/10.1021/cm970151+
  8. Y. Yan, S. R. Chaudhuri, and A. Sarkar, "Synthesis of oriented zeolite molecular sieve films with controlled morphologies", Chem. Mater., 8, 473 (1996). https://doi.org/10.1021/cm950393e
  9. H. R. Lee, H. S. Ahn, I. J. Park, S. B. Lee, and Y. Lee, "Pervaporation of aqueous iso-propyl alcohol solution using NaA zeolite membrane", Membrane Journal, 16, 25 (2006).
  10. M. Yun, H. K. Jeong, D. Jeong, H. S. Ahn, and Y. Lee, "Pervaporation characteristics of NaA type zeolite membrane substituted to $K^+$", Membrane Journal, 18, 250 (2008).
  11. Y. J. Fu, C. C. Hu, K. R. Lee, and J. Y. Lai, "Separation of ethanol/water mixtures by pervaporation through zeolite-filled polysulfone membrane containing 3-aminopropyltrimethoxysilane", Desalination, 193, 119 (2006). https://doi.org/10.1016/j.desal.2005.07.049
  12. A. Huang, Y. S. Lin, and W. Yang, "Synthesis and properties of A-type zeolite membranes by secondary growth method with vacuum seeding", J. Membr. Sci., 245, 41 (2004). https://doi.org/10.1016/j.memsci.2004.08.001
  13. G. Bonilla, M. Tsapatsis, D. G. Viachos, and G. Xomeritakis, "Fluorescence confocal optical microscopy imaging of the grain boundary structure of zeolite MFI membranes made by secondary(seeded) growth", J. Membr. Sci., 182, 103 (2001). https://doi.org/10.1016/S0376-7388(00)00549-4
  14. M. Tsapatsis, M. Lovallo, T. Okubo, M. E. Davis, and M. Sadakata, "Characterization of zeolite L nanoclusters", Chem. Mater., 7, 1734 (1995). https://doi.org/10.1021/cm00057a025
  15. J. Warzywoda, R. D. Edelman, and R. W. Thompson, "Crystallization of high-silica ZSM-5 in the presence of seeds", Zeolites, 11, 318 (1991). https://doi.org/10.1016/0144-2449(91)80294-A
  16. X. Xu, W. Yang, J. Liu, and L. Lin, "synthesis and perfection evaluation of NaA zeolite membrane", Sep. Purif. Technol., 25, 475 (2001). https://doi.org/10.1016/S1383-5866(01)00077-6
  17. E. A. Tsokanis and R. W. Thompson, "Further investigations of nucleation by initial breeding in the AI-free $NH_4$-ZSM-5 system", Zeolites, 12, 369 (1992). https://doi.org/10.1016/0144-2449(92)90032-K
  18. L. Gora and R. W. Thompson, "Controlled addition of aged mother liquor to zeolite NaA synthesis solutions", Zeolites, 18, 132 (1997). https://doi.org/10.1016/S0144-2449(96)00163-7
  19. Y. Liu, Z. Yang, C. Yu, X. Gu, and N. Xu, "Effect of seeding methods on growth of NaA zeolite membranes", Micro. Meso. Mater., 143, 348 (2011). https://doi.org/10.1016/j.micromeso.2011.03.016
  20. Z. Yang, Y. Liu, C. Yu, X. Gu, and N. Xu, "Ball-milled NaA zeolite seeds with submicron size for growth of NaA zeolite membranes", J. Membr. Sci., 392, 18 (2012).
  21. X. Zhang, H. Liu, and K. L. Yeung, "Influence of seed size on the formation and microstructure of zeolite silicalite-1 membranes by seeded growth", Mater. Chem. Phys., 96, 42 (2006). https://doi.org/10.1016/j.matchemphys.2005.06.031
  22. E. Dincer, A. Culfaz, and H. Kalipcilar, "Effect of seeding on the properties of MFI type zeolite membranes", Desalination, 200, 66 (2006). https://doi.org/10.1016/j.desal.2006.03.244
  23. C. H. Cho, K. Y. Oh, S. K. Kim, J. G. Yeo, and Y. M. Lee, "Improvement in thermal stability of NaA zeolite composite membrane by control of intermediate layer structure", J. Membr. Sci., 366, 229 (2011). https://doi.org/10.1016/j.memsci.2010.10.006
  24. H. K. Jeong, D. J. Jeong, M. Yun, H. Ahn, and Y. Lee, "Effect of crystal particle deposition on morphology of zeolite membrane and its separation performance", Membrane Journal, 18, 198 (2008).
  25. J. P. Ha and I. J. Kim, "The influence of seeding on crystallization of NaX zeolite with different adding levels", J. Korean. Ceram. Soc., 36, 1048 (1999).
  26. G. J. Kim and S. J. Nam, "Synthesis of microporous zeolitic membranes and application in alcohol/water separation", Membrane Journal, 9, 97 (1999).
  27. I. Yum, M. Yun, and Y. Lee, "Pervaporation characteristics of ion-exchanged NaA type zeolite membranes", Membrane Journal, 19, 189 (2009).
  28. P. Sharma, M. H. Han, and C. H. Cho, "An emulsion-based droplet hydrothermal synthesis method for the production of uniform sized zeolite nanocrystals", J. Colloid Interface Sci., 422, 45 (2014). https://doi.org/10.1016/j.jcis.2014.02.013