Study of surfactant-siloxane interfaces in spray-dried mesoporous silica-based spheres

We have undertaken the synthesis of spray-dried mesoporous silica-based micrometric spheres using various synthetic procedures. In this article, we focus on the relationship between textural properties and small organic groups bound to the siloxane network (residual alkoxy groups or added functions). A correlation has been found between the characteristic XRD distance and the quantity of Si-bound organic groups (measured by 1H solid-state NMR) located at the surfactant-siloxane interface which demonstrates the effect of these organic groups. However, under certain circumstances, Si-bound organic groups can be trapped inside the siloxane network. They have then a different effect on the texture, and are less accessible for further applications. In that sense, this study can also be used in a predictive way for the synthesis of mesoporous spheres with surfaces of functionalised channels.