Journal of Applied Physics · 2007 · 18 citations · 37 references
Natural SciencesMaterials EngineeringMaterials ScienceMaterials CharacterizationPolymer ChemistryPolymer MaterialsPolymer CharacterizationPolymer Physical ChemistryPolymer PhysicsPolymer StructurePolymer Thin FilmsX-ray DiffractionAbsorbed Dose EffectsGlass TransitionGlass Transition TemperatureNanostructured Polymer FilmsNanostructuresPolymer Glass TransitionSynchrotron DiffractionSynchrotron X-ray Diffraction
The glass transition temperature (Tg) of polymer nanostructures was measured using a technique based on synchrotron x-ray diffraction from periodic grating structures. Poly(methyl methacrylate) (PMMA) nanostructures consisting of 1:1 lines:spaces with a 100 nm period and 100 nm height were characterized to have a Tg of 118 °C, which is comparable to the Tg of PMMA in bulk systems. The Tg of the PMMA structures also was measured as a function of absorbed x-ray dose. Doses ranging from 0 to 2400 mJ/mm3 were delivered to the PMMA structures prior to the Tg measurements; the Tg of the structures was found to decrease from 118 °C to 95 °C, respectively. The dose dependence of the PMMA glass transition temperature can be attributed to changes in the polymer molecular weight under exposure to x rays.
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