Phase Separation in Alkoxy-Derived Silica System Containing Polyacrylamide


By inducing phase separation parallel to the sol-gel transition of alkoxy-derived silica systems, gels having both macroporous and mesoporous structures can be obtained. Using poly(acrylamide) (PAAm) as a phase-separation inducer, macro/mesoporous silica gels were synthesized. After solvent exchange by water, the size distribution of mesopores of wet gels was evaluated by thermoporometry using a differential scanning calorimetry (DSC). Alternatively, gels were evaporation-dried after solvent exchange by ethanol or water/ethanol, followed by heat-treatment to completely remove volatile and organic components. Characterization of the dried or heat-treated samples was carried out using a scanning electron microscope (SEM) and by nitrogen adsorption measurements. Experimental results showed that the interaction between PAAm and silica is not so strong as the case of polymers having poly(oxyethylene) chains. The contribution of the secondary phase separation within the crosslinking silica-rich phase was suggested to be responsible for the mesopore formation in the PAAm-silica system.

This is a preview of subscription content, access via your institution.


  1. 1.

    K. Nakanishi, H. Minakuchi and N. Soga, J. Sol-Gel Sci. Tech. 8, 547–552 (1997)

    CAS  Google Scholar 

  2. 2.

    N. Tanaka, H. Kobayashi, K. Nakanishi, H. Minakuchi, N. Ishizuka, Anal. Chem. August 1, 421A–429A (2001)

  3. 3.

    K. Nakanishi, J. Porous Mater. 4, 67–112 (1997).

    CAS  Article  Google Scholar 

  4. 4.

    K. Nakanishi, R. Takahashi, T. Nagakane, K. Kitayama, N. Koheiya, H. Shikata and N. Soga, J. Sol-Gel Sci. Tech. 17, 1–20 (2000)

    Article  Google Scholar 

  5. 5.

    Michael R. Landry, Thermochim. Acta 433, 27–50 (2005).

    CAS  Article  Google Scholar 

  6. 6.

    T. Yamamoto, A. Endo, Y. Inagi, T. Ohmori and M. Nakaiwa, J. Colloid Interface Sci. 284, 614–620 (2005).

    CAS  Article  Google Scholar 

  7. 7.

    T. Yamamoto, S.R. Mukai, K. Nitta, H. Tamon, A. Endo, T. Ohmori and M. Nakaiwa, Thermochim. Acta 439, 74–79 (2005).

    CAS  Article  Google Scholar 

  8. 8.

    R. Takahashi, K. Nakanishi and N. Soga, Faraday Discuss. 101, 249–263 (1995).

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Kousuke Kawamoto.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kawamoto, K., Nakanishi, K. & Hanada, T. Phase Separation in Alkoxy-Derived Silica System Containing Polyacrylamide. MRS Online Proceedings Library 1007, 401 (2007).

Download citation