Growth of mesoporous materials within colloidal crystal films by spin-coating

A combination of colloidal crystal planarization, stabilization, and novel infiltration techniques is used to build a bimodal porous silica film showing order at both the micron and the nanometer length scale. An infiltration method based on the spin-coating of the mesophase precursor onto a three-dimensional polystyrene colloidal crystal film allows a nanometer control tuning of the filling fraction of the mesoporous phase while preserving the optical quality of the template. These materials combine a high specific surface arising from the nanopores with increased mass transport and photonic crystal properties provided by the order of the macropores. Optical Bragg diffraction from these type of hierarchically ordered oxides is observed, allowing performing of optical monitoring of the different processes involved in the formation of the bimodal silica structure.