By combining traditional Small Angle Neutron Scattering (SANS) and Spin-Echo Modulated
Small Angle Neutron Scattering (SEMSANS) for the first time, an international collaboration
was able to investigate the mechanism behind the initial growth of mesostructured silicasurfactant particles at the nano- and micro-metre scales simultaneously. The study, published
in ACS Applied Materials & Interfaces, provides valuable insights on the formation of these
particles, which are the precursors to thin films that grow at the solution interface.
Two possible mechanisms for the self-assembly of these
films from a silica-surfactant system have been suggested,
but neither has previously been confirmed experimentally. This
study used the unique combination of SANS and SEMSANS
on Larmor to study the behaviour of the micelles and growing
particles in solution to determine which mechanism occurs,
under these conditions.
The researchers were able to see the surfactant micelles
elongate on addition of the silica species, before they
aggregate to form droplets. After this droplet formation has
occurred, the micelles inside the droplet order into large
particles with an ordered mesostructure. The particles then
migrate to the air/liquid interface, forming the thin film.
The ability to manipulate the structure of mesoporous thin
films, and the pore size within them, gives the films potential
applications in a wide variety of fields including catalysis and
Related publication: “Mesoporous Silica Formation Mechanisms Probed Using Combined Spin–Echo Modulated
Small-Angle Neutron Scattering (SEMSANS) and Small-Angle Neutron Scattering (SANS).” ACS Appl. Mater.
Interfaces, 12, 25, 28461–28473 (2020)