Sonocatalyst

Ultrasound has potentially important applications in both homogeneous and heterogeneous catalytic systems. Heterogeneous catalysis is generally more industrially important than homogeneous systems. For example, virtually all of the petroleum industry is based on a series of catalytic transformations. Heterogeneous catalysts often require rare and expensive metals. The catalytic converters used on automobiles to lessen pollution, for example, use platinum or rhodium, which are enormously expensive; rhodium costs about $1500 dollars per ounce!

Using ultrasound offers some hope of activating less reactive, but also less costly, metals. Some early investigations of the effects of ultrasound on heterogeneous catalysis can be found in the Soviet literature. In this early work, increases in turnover rates were usually observed upon ultrasonic irradiation, but were rarely more than 10-fold. In the case of modest rate increases, it appears likely that the cause is increased effective surface area; this is especially important in the case of catalysts supported on brittle solids.

Sonoluminescence

Sonofusion

Chemoluminescence

Sonocrystalisation

Polymer and Biro-    materials