The curved feature of ultrasound-treated graphitic sheets

When examined under a high-resolution transmission microscope (HRTEM), highly oriented pyrolitic graphite (HOPG), after ultrasound treatment, is found to contain some bent graphitic sheets. These bent structures are ordered graphitic sheets, which have specific bend angles that are a multiple of 30° (from 30° to 180°). We speculate that the creation and variation of bend angles is a result of interplay between the conformation of sp3-like defects and the ultrasound wave impact.