Question

What causes different sizes of silver nanoparticles to appear as different colors in solution?

Answer 1

Different sizes of silver nanoparticles appear as different colors in solution because silver nanoparticles are easily aggregated and when the aggregation occurs the colour of the nanoparticles changes. These particles absorb and scatter light very efficiently. After aggregation, the strong interaction between nanoparticles with light occurs due to the conduction electrons present on the surface of the silver metal undergo movements when they are excited by lights of different wavelengths.