Sub-minute formation of supported nanoporous mesoscale patterns programmed by surface energy

► Substrate surface energy dictates thin film nanostructure. ► Nanoparticle-polymer systems above decomposition temperature of polymer. ► Entropy-enthalpy interplay between nanoparticles, polymer and substrate surface. ► Chemically patterned substrates used for spontaneous patterning of nanoporous films. ► Ensemble behavior of the nanoparticles studied using Ellipsometry.