Ruthenium staining for morphological assessment and patterns formation in block copolymer films

The selective staining by ruthenium tetroxide (RuO4) was used in combination with Atomic Force Microscopy and calcination to discriminate and assign microphases at the surfaces of films of complex polymer systems. This paper evaluates this technique on thin films of polystyrene-b-polylactide (PS-b-PLA) and polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) and demonstrates its efficiency on complex thin film of binary blend of PS-b-PMMA and PLA. This method overcomes difficulties in the interpretation of AFM images by assigning PS microphase. In addition we show that this methodology could yield nanostructured inorganic materials with tunable structures such as perforated layers or nanowires that could find potential applications in the fabrication of high specific surface area Ru oxide-based materials.