Hierarchical porous materials often serve as a carrier for functional nanoparticles in applications like catalysis, sensing, or energy storage. However, it is a major challenge to find methods to prepare such hybrid materials at an industrial scale.

James Watkins, University of Massachusetts, Amherst, USA and colleagues have developed a simple strategy to rapidly coat large areas of polyethylene terephthalate (PET) with porous hybrid films containing gold nanoparticles in a silica/carbon matrix. The PET substrate is coated with a mixture of gold nanoparticles, a block copolymer as a sacrificial template, and polyhedral oligomeric silsesquioxane (POSS) as a silica precursor.

The coated samples are heated with a xenon flash lamp using the localized surface plasmon resonance of the gold nanoparticles. This photothermal treatment leads to the removal of the block copolymer and oxidation of POSS to a silica network, while the gold nanoparticles remain well dispersed. The resulting thin films exhibit mesopores on the surface and a foam-like macroporous network underneath.

According to the researchers, this method can be scaled up, is compatible with roll-to-roll manufacturing for flexible devices, and can be adapted for other porous hybrid films with different functionalities.

• Rapid, Large-Area Synthesis of Hierarchical Nanoporous Silica Hybrid Films on Flexible Substrates,
  D.-P. Song, A. Naik, S. Li, A. Ribbe, J. J. Watkins,
  J. Am. Chem. Soc. 2016.
  DOI: 10.1021/jacs.6b06947