Two different colours from the same cup Vittorio Saggiomo
Is this goblet purple or brown? Well, it depends.
The cup is dichroic, meaning that it changes colour under different lighting conditions, from clear purple when light is transmitted through it, to opaque brown when light reflects off it.
Vittorio Saggiomo and colleagues at Wageningen University & Research in the Netherlands created the cup from gold nanoparticles and a 3D-printable clear plastic.
To do this, they mixed nanoparticles with citrate – a derivative of the acid that makes lemons sour – to create a dichroic liquid. The plastic was then dissolved in the…
