Wave propagation and pattern formation on a porcelain membrane

Wave velocity in (i) ferroin + malonic acid + BrO3- + H2SO4, (ii) ferroin malonic acid + acetone + BrO3- + H2SO4, (iii) ferroin + Ce4+ + malonic aci d + BrO3- + H2SO4, and (iv) ferroin + Ce4+ + malonic acid s acetone + BrO3- + H2SO4 systems have been investigated with and without a porous unglazed porcelain membrane. Results for wave velocity v are found to fit the data f or the corresponding systems. Dependence of wave velocity on [H+] and [BrO3 -] has been studied. In contrast to systems (i) and (ii), the velocity is f ound to be inversely proportional to [H+] for systems (iii) and (iv). One-p arameter equation satisfies the data for systems (i) and (iii), while a two -parameter equation fits the data for systems (ii) and (iv), both in soluti on as well as on membrane. Wave velocity is found to be enhanced when aceto ne is present in the system. Similarly, the wave velocity is found to be hi gher on membrane than that in solution. Pattern formed on membrane persists so long as there is aqueous solution in the pores of the membrane.