Fig. 6

Nanobubble formation in an aqueous solution of gold nanorods with a measured pH ~7 and trace amounts of the surfactant cetrimonium bromide (CTAB). Imaging was performed with at beam current ~1 nA and beam radius ~2 μm resulting in a dose rate of 7.5 × 10⁷ (Gy/s) or 20 (e⁻/Ų-s). a Bubble radius as a function of frame. b Comparison of raw, binary, and masked images. c Bubble intensity weight centroid (squares) with bubble edge outline, color-coded in time