The internal structures of thin films prepared from a long chain polystyrene-b-poly(ethylene oxide) (PS-b-PEO) diblock copolymer with nanoholes and densely branched morphologies were studied. The thickness of the lamellar mesophase repeat unit and the orientation of the PEO crystalline chain stems within the thin film were determined using grazing-incidence small- and wide-angle X-ray scattering (GISAXS & GIWAXS). The surface morphologies measured by atomic force microscopy were linked to the dimensions and orientations of the internal structures. The film thicknesses for the nanoholes morphology were discovered to deviate from an integer multiple of the diblock copolymer lamellar units (70 nm), promoting the hole textures. Dewetted architectures were obtained by annealing freshly prepared films at an elevated temperature in a toluene/water vapour environment. Following this, some PEO chains crystallized within the dewetted large holes, resulting in a densely branched morphology (DBM). The crystalline chain stems of the crystalline lamellar were found to be roughly perpendicular to the film substrate with thicknesses of about 10 nm within the dewetted large holes. This corresponds to the diffusion-limited aggregated model.
Author (s) DetailsDr. Charles Darko
Department of Materials, The University of Manchester, Oxford Road, M13 9PL, Manchester, United Kingdom.
View Book :- https://stm.bookpi.org/CACS-V1/article/view/1798
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