Effect of Grafting Density of Random Copolymer Brushes on Perpendicular Alignment in PS-b-PMMA Thin Films
| Autor: | Yeongsik Kim, Du Yeol Ryu, Sungmin Park, Nathan Rebello, Vaidyanathan Sethuraman, Wooseop Lee, Venkat Ganesan |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Polymers and Plastics Scattering Organic Chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Grafting Methacrylate 01 natural sciences 0104 chemical sciences Inorganic Chemistry chemistry.chemical_compound chemistry Polymer chemistry Materials Chemistry Perpendicular Copolymer Grazing-incidence small-angle scattering Thin film Composite material Methyl methacrylate 0210 nano-technology |
| Zdroj: | Macromolecules. 50:5858-5866 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/acs.macromol.7b00133 |
| Popis: | We modulated the grafting density (σ) of a random copolymer brush of poly(styrene-r-methyl methacrylate) on substrates to probe its effect on the formation of perpendicularly aligned lamellae of polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA). Supported by coarse-grained simulation results, we hypothesized that an increase in σ will allow us to systematically tune the block copolymer interfacial interactions with the substrates from being preferential to one of the blocks to being neutral toward both blocks and will thereby facilitate enhanced regimes of perpendicularly aligned lamellae. We verified such a hypothesis by using a simple grafting-to approach to modify the substrates and characterized the thickness window for perpendicular lamellae as a function of brush thickness (or σ) on the grafted substrates using scanning force microscopy (SFM) images and grazing incidence small-angle X-ray scattering (GISAXS) measurements. The experimental results validated our hypothesis and suggested that the σ o... |
| Databáze: | OpenAIRE |
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