CHEMICAL WAVES IN MESOPOROUS MEDIA

Chemical waves in the Belousov-Zhabotinsky (BZ) reaction were investigated in mesoporous glass (vycor 7930). Some characteristics such as wavelengths or pattern sizes, periods and velocities of chemical waves have been found in the glass systems. The velocity of the waves in the vycor glass (pore diameter similar to 40 Angstrom, ca. 10 times larger than the reacting molecules) was about 1/3 of that in aqueous systems. A microscopic model for the wave propagation in mesoporous glass is presented. The reduced velocity of the chemical waves is explained in terms of the reaction and diffusion in a fractal-like network of narrow channels. Porous glass has been found to be a useful heterogeneous medium for studying chemical patterns under open conditions.