stress response of silver nanoparticle film on a water subphase

We examine the stress response of a film composed of dodecanethiol-ligated silver nanoparticles and supported on a water subphase, using optical microscopy and synchrotron x-ray techniques (x-ray reflectivity and grazing incidence x-ray diffraction). We observe a monolayer-to-bilayer transition, which is followed by wrinkling and folding of the nanoparticle film. The results are quantitatively different from a similar film of gold nanoparticles, which undergoes a monolayer-to-trilayer transition and wrinkles with a longer wavelength. The silver film is also less covered in wrinkles and folds than the gold film at similar compressive strains, and the wrinkles quickly relax when compression is stopped.