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Multiscale Structures Aggregated by Imprinted Nanofibers for Functional Surfaces
Published on: September 11, 2018
Structural relaxation of polymer glasses at surfaces, interfaces, and in between
Rodney D Priestley1, Christopher J Ellison, Linda J Broadbelt
1Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.
Science (New York, N.Y.)
|July 16, 2005
Summary
Polymer structural relaxation slows significantly near surfaces and interfaces. This effect extends over 100 nm into polymer films, impacting material properties.
Area of Science:
- Polymer Science
- Materials Science
- Physical Chemistry
Background:
- Understanding polymer dynamics near interfaces is crucial for material design.
- Glassy-state structural relaxation governs long-term polymer performance.
- Surface and interface effects can alter bulk polymer properties.
Purpose of the Study:
- To quantify the impact of surfaces and interfaces on polymer structural relaxation.
- To determine the spatial extent of these effects within polymer films.
Main Methods:
- Utilized fluorescence monitoring in multilayer polymer films.
- Analyzed structural relaxation rates of poly(methyl methacrylate) (PMMA).
- Compared relaxation rates at free surfaces and silica interfaces to bulk PMMA.
Main Results:
- Structural relaxation rate reduced by 2x at free surfaces and 15x at silica interfaces.
- Near-complete arrest of relaxation observed at the silica interface.
- Slowed relaxation observed up to 100 nm into the polymer film.
Conclusions:
- Surfaces and interfaces dramatically slow polymer structural relaxation.
- These effects penetrate deeper into the polymer than changes in glass transition temperature.
- Interface-induced changes in polymer dynamics are significant and long-range.
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