A different look at 'wetting' and 'dewetting' using synchrotron X-rays

'Wetting' and 'dewetting' acquire different meaning when the 'solid' and 'liquid' are composed of similar, complex molecules. A typical case is for amphiphiles forming monolayers and multilayers. These have been studied using X-ray scattering and spectroscopy and some of the results are presented here. Amphiphiles bearing transition elements with unfilled d-orbitals have symmetric co-ordination in the metal-organic moiety and monolayers of these molecules behave as 'liquids' as they are deposited on the multilayers of the same molecules. However, for elements with filled d-orbitals the coordination shows asymmetry and monolayers of such molecules dewet and form nanocrystals as they are similarly deposited, providing a new template for nanocrystal growth. (author)