Combining two differently sized magnetic nanoparticles can lead to interesting self-assembly effects. This follows on neatly from my previous self-assembly post. So how do 7 nm particles combined with 15 nm particles self-assemble?
The high surface-tension of evaporating water droplets push the particles together, forcing them to assemble in a space-efficient array. Interestingly, the particles appear to self-assemble based on size, where 7 nm particles and 15 nm particles separate so that they can pack together more efficiently. If the size ratio changes, different effects could be seen such as small particles fitting in between spaces left by larger particles. Some neat images:
7 nm and 15 nm diameter magnetic nanoparticles self-assembling
