Inorganic nanoporous films from block copolymer thin film

A method for preparing inorganic nanoporous films by using the template with polystyrene nanopillars oriented vertically to a substrate was demonstrated. The nanopillar structure was prepared by thermal annealing and subsequent solvent vapor annealing of polystyrene-b-PMMA film followed by removal of the PMMA matrix. The film was annealed under acetone vapor to have vertically oriented cylindrical microdomains of PS block, and the PS nanopillars in the film were removed by thermal decomposition at high-temperature, generating inorganic nanoporous films. Field emission-scanning electron microscopy (FE-SEM) images showed that straight cylindrical pores spanning the entire film thickness were observed for all of the inorganic films. Experimental investigation showed that the inorganic nanoporous films exhibit good thermal and mechanical stabilities, and could be employed for special membranes for the separation at very high temperature.