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Reduced Polymer Mobility Near the Polymer Solid Interface as Measured by Neutron Reflectivity



Eric K. Lin, R Kolb, Sushil K. Satija, Wen-Li Wu


Neutron reflectometry is used to measure the rate of interdiffusion over distances less than 200 between bilayer samples of deuterated and hydrogenated poly(methyl methacrylate) (PMMA) films with the polymer-polymer interface located near the native oxide surface of a silicon wafer. In this work, the effects of the attractive interaction between the polymer and the substrate and of the molecular weight of each polymer layer are determined. The film thickness and the molecular weight of the lower d-PMMA layer was kept constant with a thickness of approximately one radii of gyration (Rg) of the polymer and the molecular weight of the upper hydrogenated layer was varied. Although earlier experiments show that the mobility of the polymer chains within Rg of the substrate is much lower than that of the bulk, we find that the rate of interdiffusion is strongly dependent upon the molecular weight of the top layer.
No. 11


chain mobility, neutron reflectivity, polymer interdiffusion, polymer-solid interface


Lin, E. , Kolb, R. , Satija, S. and Wu, W. (1999), Reduced Polymer Mobility Near the Polymer Solid Interface as Measured by Neutron Reflectivity, Macromolecules, [online], (Accessed June 18, 2024)


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Created May 31, 1999, Updated October 12, 2021