Ultrasonic cavitation of molten gallium in water: Entrapment of organic molecules in gallium microspheres

Simultaneous formation of gallium microspheres and entrapment of organic materials within them can be accomplished by applying ultrasonic energy to a heated solution of the organic substance that contains the molten metal. This method was used with aqueous solutions (5-10 mM) of four organic compounds (phenanthroline, Congo Red, crystal violet and rhodamine 6G) at 55 °C, a temperature at which the gallium is molten. Irradiation with ultrasonic energy for ca. 3 min dispersed the molten gallium into microscopic spheres, which were found to contain various amounts of these organic compounds. Immersion of the isolated spheres in pure water results in slow leaching of some of the above compounds.