Structuring of silica nanoparticle suspension by neutron reflectivity

 11 March 2020              Credit: BNC / L. Bottyán Self-organization of the silica nanoparticle suspension normal to the silica–water interface
The behavior of colloidal particles at a water-solid interface is relevant in material science, food processing, medicine and environmental enginee-ring.  A team from the University of Geneva with researchers from the Budapest Neutron Centre used neutron reflectivity to study colloidal silica nanoparticle suspensions near the like-charged native-oxide-covered surface of Si. Intriguingly, the nanospheres develop a self-organized damped, oscillatory concentration profile normal to the interface, as demonstrated in the figure.

P. Maroni, M. Gvaramia, D. Kosior, K. Kubiak, L. Scarratt, A. M. Smith, D. G. Merkel, L. Bottyán, M. Borkovec,  Phys. Chem. Chem. Phys. 2020, 22,  6449       DOI:

  Neutron reflectivity of an aquous suspension of silica nano-spheres of volume fraction 0.10 along with the extracted scattering length density (SLD) profile as inset   Schematic representation (a) and calculated volume fraction profile (b) of the water - silica nanosphere suspension near the interface