Professor James Economy's Group
Activated Inorganic Fibers Templated from ACF
In recent years, inorganic materials have attracted much attention as effective adsorbents for air and water treatment. Some of them have specific adsorption ability to some gases, such as MgO and CaO for high-temperature sequestration of CO2 1, while MgO and ZnO for H2S 2. CaO, MgO, CoO and ZnO dispersed activated carbons display antibacterial activity for B. subtilis and S. aureus 3. Inorganic ion exchangers (e.g. M2Ti2O3SiO4.nH2O (M = H, Na), crystalline silicotitanates) would allow highly selective removal of the trace nuclear contaminants such as Cs+ and Sr 2+ from water 4. TiO2 has been used as a photocatalyst for water treatment 5; and Ag as an antibacterial for E.coli 6.
Templating is a technique for the preparation of porous materials that has received widespread attention in the literature7. The preparation of silica-based mesoporous materials by using surfactant aggregates as structure directing agents is a successful example of this synthetic strategy 8.
An inorganic adsorbent fiber would be a valuable material because it could have much higher contact efficiency and thermal/oxidative stability allowing it to be regenerated at higher temperatures in air.
A number of new inorganic fibers have been prepared in our group by a templating approach where the ACF is coated with the desired metal oxide precursor and then the carbon burned out using air to yield a high surface area oxide fiber with the reverse image of the ACF. Fibers of ZrO2, TiO2, MgO, CaO Al2O3 and ZnO have been prepared in this manner and it is expected that many of these materials will find use as catalyst support which others could be used for sequestering CO2 at elevated temperatures.
Figure 1. Cartoon for the conversion from ACF to Inoranic fibers
Figure 2. ACF fabric to ZrO2 fabric
1. Kyaw, K., Kanamori, M., Matsuda, H., Hasatani, M. (1996). Study of carbonation reactions of Ca-Mg oxides for high temperature energy storage and heat transformation. Journal of Chemical Engineering of Japan. 29(1), 112-18.
2. Squires, A.M., Graff, R.A. and Pell, M. (1971). Desulfurization of fuels with calcined dolomite. I. Introduction and first kinetic results. Chemical Engineering Progress, Symposium Series, 67(1115), 23-34.
3. Tamai, H., Katsu, N., Ono, K. and Yasuda, H. (2001). Antibacterial activated carbons prepared from pitch containing organometallics. Carbon. 39(13), 1963-1969.
4. Solbr, S., Allison, N., Waite, S., Mikhalovsky, S.V., Bortun, A. I., Bortun, L.N. and Clearfield, A. (2001). Cesium and Strontium Ion Exchange on the Framework Titanium Silicate M2Ti2O3SiO4.nH2O (M = H, Na). Environmental Science and Technology. 35(3), 626-629.
5. Legrini, O., Oliveros, E. and Braun, A. M. (1993). Photochemical processes for water treatment. Chemical Reviews (Washington, DC, United States). 93(2), 671-98.
6. Cowlishaw, J., Spadaro, J. A. and Becker, R.O. (1982). Inhibition of enzyme induction in E. coli by anodic silver. Journal of Bioelectricity. 1(3), 295-304.
7. Benak, K., (2001). Synthesis and characterization of novel adsorbent fibers, Ph.D. thesis, University of Illinois at Urbana-Champaign,
8. Kresge, C. T., Leonowicz, M. E., Roth, W. J., Vartuli, J. C. and Beck, J. S. (1992). Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism. Nature 359(6397), 710-12.