Rapid, Large-Area Synthesis of Hierarchical Nanoporous Silica Hybrid Films on Flexible Substrates

We report a simple strategy for the creation of large-area nano­porous hybrid films of silica, carbon, and gold on poly­ethylene tere­phthalate via photo­thermal processing. This method enables the selective heating of light-absorbing thin films on low-temperature substrates using sub-milli­second light pulses generated by a xenon flash lamp. The film contains gold nano­particles as the nano­heaters to convert light energy to heat, a sacrificial block copolymer surfactant to generate mesopores, and cross-linked poly­hedral oligo­meric silsesqui­oxane as the silica source to form the skeleton of the porous structure. Hier­archical porous structures are achieved in the films after photo­thermal treatment, with uniform meso­pores (44–48 nm) on the surface and inter­connected macro­pores (>50 nm) under­neath resulting from a foaming effect during release of gaseous decomposition products. The loading of gold nano­particles is up to 43 wt % in the product, with less than 2 wt % organic residue. This rapid and large-area process for the synthetis of porous structures is compatible with roll-to-roll manufacturing for the fabrication of flexible devices.