Abstract
The mesoscale assembly process is sensitive to additives that can modify the interactions of the crystal nucleus and the developing crystals with solid surfaces and soluble molecules. However, the presence of additives is not a prerequisite for the mesoscale transformation process. In this study, ZnO sheet networks were synthesized on Al foils by a hydrothermal process. Scanning electron microscopy and transmission electron microscopy images confirmed that under ultrasonic vibration, monolithic polycrystalline ZnO sheets transformed into hexagon-like mesocrystalline tubes or rods. The formation mechanism was discussed.