Figure 3.

Transmission electron micrographs of freeze-dried bubbles prepared using the T-junction device (figure 2). (a) Cross-section through a bubble showing the gold nanoparticles concentrated at the surface. (b) Magnified image of region ‘X’ in (a), showing 15 nm diameter gold particles. (c) Distribution of gold nanoparticles at the interface of three adjacent bubbles. (d) Energy-dispersive X-ray analysis and selected-area diffraction pattern of point ‘Y’ in (c) confirming the presence of gold at the bubble surface.