Electronic Materials Letters

, Volume 14, Issue 2, pp 83–88 | Cite as

Fabrication of Conductive Macroporous Structures Through Nano-phase Separation Method

  • Soohyun Kim
  • Hyunjung Lee


Thermoelectric power generation performance is characterized on the basis of the figure of merit, which tends to be high in thermoelectric materials with high electrical conductivity and low thermal conductivity. Porous structures cause phonon scattering, which decreases thermal conductivity. In this study, we fabricated porous structures for thermoelectric devices via nano-phase separation of silica particles from a polyacrylonitrile (PAN) matrix via a sol–gel process. The porosity was determined by control of silica particle size with various the mixing ratio of tetraethylorthosilicate as the precursor of silica particles to PAN. High electrical conductivity was maintained by subsequent carbonization of the PAN matrix in spited of a high porosity. As the results, the conductive porous structures having porosity from 13.9 to 83.3 (%) was successfully fabricated, keeping their electrical conductivities.

Graphical Abstract


Conductive porous structure Macroporous structure Nanophase separation Thermoelectric materials 



This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (NRF-2017R1A2B2010552 and 2015R1A5A7037615) and Civil Military Technology Cooperation Center (15-CM-SS-03 and 15-CM-EN-08).


  1. 1.
    Naboka, O., Sanz-Velasco, A., Lundgren, P., Enoksson, P., Gatenholm, P.: Cobalt (II) chloride promoted formation of honeycomb patterned cellulose acetate films. J. Colloid Interface Sci. 367, 485 (2012)CrossRefGoogle Scholar
  2. 2.
    Li, Y., Fu, Z.Y., Su, B.L.: Hierarchically structured porous materials for energy conversion and storage. Adv. Funct. Mater. 22, 4634 (2012)CrossRefGoogle Scholar
  3. 3.
    Zukalova, M., Zukal, A., Kavan, L., Nazeeruddin, M.K., Liska, P., Grätzel, M.: Organized mesoporous TiO2 films exhibiting greatly enhanced performance in dye-sensitized solar cells. Nano Lett. 5, 1789 (2005)CrossRefGoogle Scholar
  4. 4.
    Liu, W., Chen, Z., Zhou, G., Sun, Y., Lee, H.R., Liu, C., Yao, H., Bao, Z., Cui, Y.: 3D porous sponge-inspired electrode for stretchable lithium-ion batteries. Adv. Mater. 28, 3578 (2016)CrossRefGoogle Scholar
  5. 5.
    Wolf, A., Brendel, R.: Thermal conductivity of sintered porous silicon films. Thin Solid Films 513, 385 (2006)CrossRefGoogle Scholar
  6. 6.
    Snyder, G.J., Toberer, E.S.: Complex thermoelectric materials. Nat. Mater. 7, 105 (2008)CrossRefGoogle Scholar
  7. 7.
    Cornett, J.E., Rabin, O.: Thermoelectric figure of merit calculations for semiconducting nanowires. Appl. Phys. Lett. 98, 182104 (2011)CrossRefGoogle Scholar
  8. 8.
    Cornett, J.E., Rabin, O.: Universal scaling relations for the thermoelectric power factor of semiconducting nanostructures. Phys. Rev. B 84, 205410 (2011)CrossRefGoogle Scholar
  9. 9.
    Li, J.F., Liu, W.S., Zhao, L.D., Zhou, M.: High-performance nanostructured thermoelectric materials. NPG Asia Mater. 2, 152 (2010)CrossRefGoogle Scholar
  10. 10.
    Shu, J., Xia, R., Qian, J., Miao, J., Su, L., Cao, M., Lin, H., Chen, P., Chen, J.: Preparation and study on thermal conductive composites of chlorinated polyethylene rubber reinforced by boron nitride particles. Macromol. Res. 24, 640 (2016)CrossRefGoogle Scholar
  11. 11.
    Kim, W., Zide, J., Gossard, A., Klenov, D., Stemmer, S., Shakouri, A., Majumdar, A.: Thermal conductivity reduction and thermoelectric figure of merit increase by embedding nanoparticles in crystalline semiconductors. Phys. Rev. Lett. 96, 045901 (2006)CrossRefGoogle Scholar
  12. 12.
    Tang, J., Wang, H.-T., Lee, D.H., Fardy, M., Huo, Z., Russell, T.P., Yang, P.: Holey silicon as an efficient thermoelectric material. Nano Lett. 10, 4279 (2010)CrossRefGoogle Scholar
  13. 13.
    Kim, H., Lee, J.K., Park, S.D., Ryu, B., Lee, J.E., Kim, B.S., Min, B.K., Joo, S.J., Lee, H.W., Cho, Y.-R.: Enhanced thermoelectric properties and development of nanotwins in Na-doped Bi0.5Sb1.5Te3 alloy. Electron. Mater. Lett. 12, 290 (2016)CrossRefGoogle Scholar
  14. 14.
    Lee, J.H., Galli, G.A., Grossman, J.C.: Nanoporous Si as an efficient thermoelectric material. Nano Lett. 8, 3750 (2008)CrossRefGoogle Scholar
  15. 15.
    Lee, S.H., Park, J.S., Lim, B.K., Mo, C.B., Lee, W.J., Lee, J.M., Hong, S.H., Kim, S.O.: Highly entangled carbon nanotube scaffolds by self-organized aqueous droplets. Soft Matter 5, 2343 (2009)CrossRefGoogle Scholar
  16. 16.
    Warren, S.C., Perkins, M.R., Adams, A.M., Kamperman, M., Burns, A.A., Arora, H., Herz, E., Suteewong, T., Sai, H., Li, Z.: A silica sol–gel design strategy for nanostructured metallic materials. Nat. Mater. 11, 460 (2012)CrossRefGoogle Scholar
  17. 17.
    Johnson, S.A., Ollivier, P.J., Mallouk, T.E.: Ordered mesoporous polymers of tunable pore size from colloidal silica templates. Science 283, 963 (1999)CrossRefGoogle Scholar
  18. 18.
    Imhof, A., Pine, D.: Ordered macroporous materials by emulsion templating. Nature 389, 948 (1997)CrossRefGoogle Scholar
  19. 19.
    Cui, L., Peng, J., Ding, Y., Li, X., Han, Y.: Ordered porous polymer films via phase separation in humidity environment. Polymer 46, 5334 (2005)CrossRefGoogle Scholar
  20. 20.
    Jung, D., Cho, S.G., Moon, T., Sohn, H.: Fabrication and characterization of porous silicon nanowires. Electron. Mater. Lett. 12, 17 (2016)CrossRefGoogle Scholar
  21. 21.
    Kim, S., Kwag, D.S., Lee, D.J., Lee, E.S.: Acidic pH-stimulated tiotropium release from porous poly(lactic-co-glycolic acid) microparticles containing 3-diethylaminopropyl-conjugated hyaluronate. Macromol. Res. 24, 176 (2016)CrossRefGoogle Scholar
  22. 22.
    Lee, J.P., Choi, S., Park, S.: Preparation of silica nanospheres and porous polymer membranes with controlled morphologies via nanophase separation. Nanoscale Res. Lett. 7, 1 (2012)CrossRefGoogle Scholar
  23. 23.
    Brinker, C.J., Keefer, K.D., Schaefer, D.W., Ashley, C.S.: Sol-gel transition in simple silicates. J. Non Cryst. Solids 48, 47 (1982)CrossRefGoogle Scholar
  24. 24.
    Nakanishi, K.: Pore structure control of silica gels based on phase separation. J. Porous Mat. 4, 67 (1997)CrossRefGoogle Scholar
  25. 25.
    Tan, L., Pan, D., Pan, N.: Gelation behavior of polyacrylonitrile solution in relation to aging process and gel concentration. Polymer 49, 5676 (2008)CrossRefGoogle Scholar
  26. 26.
    Zhou, Z., Lai, C., Zhang, L., Qian, Y., Hou, H.: Development of carbon nanofibers from aligned electrospun polyacrylonitrile nanofiber bundles and characterization of their microstructural, electrical, and mechanical properties. Polymer 50, 2999 (2009)CrossRefGoogle Scholar
  27. 27.
    Fitzer, E., Frohs, W., Heine, M.: Optimization of stabilization and carbonization treatment of PAN fibres and structural characterization of the resulting carbon fibres. Carbon 24, 387 (1986)CrossRefGoogle Scholar
  28. 28.
    Rahaman, M.S.A., Ismail, A.F., Mustafa, A.: A review of heat treatment on polyacrylonitrile fiber. Polym. Degrad. Stab. 92, 1421 (2007)CrossRefGoogle Scholar
  29. 29.
    Nataraj, S., Yang, K., Aminabhavi, T.: Polyacrylonitrile-based nanofibers—a state-of-the-art review. Prog. Polym. Sci. 37, 487 (2012)CrossRefGoogle Scholar
  30. 30.
    Chen, J., Harrison, I.: Modification of polyacrylonitrile (PAN) carbon fiber precursor via post-spinning plasticization and stretching in dimethyl formamide (DMF). Carbon 40, 25 (2002)CrossRefGoogle Scholar
  31. 31.
    Cuevas, F.G., Montes, J.M., Cintas, J., Urban, P.: Electrical conductivity and porosity relationship in metal foams. J. Porous Mater. 16, 675 (2008)CrossRefGoogle Scholar
  32. 32.
    Chung, W.H., Hwang, H.J., Kim, H.S.: Flash light sintered copper precursor/nanoparticle pattern with high electrical conductivity and low porosity for printed electronics. Thin Solid Films 580, 61 (2015)CrossRefGoogle Scholar
  33. 33.
    Bark, H., Lee, J., Lim, H., Koo, H.Y., Lee, W., Lee, H.: Simultaneous nitrogen doping and pore generation in thermo-insulating graphene films via colloidal templating. ACS Appl. Mater. Interfaces 8, 31617 (2016)CrossRefGoogle Scholar

Copyright information

© The Korean Institute of Metals and Materials 2018

Authors and Affiliations

  1. 1.School of Materials Science and EngineeringKookmin UniversitySeoulKorea

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