Investigating Sequential Vapor Infiltration Synthesis On Block-Copolymer-Templated Titania Nanoarrays

Sequential vapor infiltration synthesis (SVIS) within block-copolymer templates has emerged as an attractive means for the controlled formation of metal oxide nanoarrays on arbitrary substrates. This approach takes advantage of the molecular-level controls that are inherent in the production of the template and the exposure tools that are available for the vapor-phase growth of materials. To take adequate advantage of these controls and their dependencies on any environmental factors, it is essential to understand the mechanisms that govern nanostructure morphology at different stages of the growth process. To this end, this work correlates the evolution of the internal structure with the chemical functionality of block-copolymer templates in response to different conditions of exposure to volatile titania precursors. The evolution is followed by mapping structural and functional information at lateral and vertical resolutions down to a few nanometers through a combination of electron microscopies [scanning electron microscopy (SEM), transmission electron microscopy (TEM), cross sections], X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS).