ISIS Neutron and Muon Source Data Journal

The 10 nm liquid-like layer in thin polymer films does not exist, reflectivity can prove it

Abstract: Since the discovery (1994) of liquid-like layers in glassy polymers there has been a persistent dogma that a 10 nm liquid like layer exists at the surface of supported polymer thin films. This liquid-like layer manifests as a significant reduction (~ 10°C -30°C) in the glass transition temperature (Tg) of an ultra-thin film, this means orders of magnitude increase in polymer mobility and dynamics. We have evidence which shows this phenomenon simply does not exist and is instead an artefact due to fundamental limitations with the technique originally used to prove its existence, ellipsometry. Unifying our results from ellipsometry with neutron and X-ray reflectivity will unambigously show that when measured correctly, there is no reduction in the Tg of a thin film. Such work is of huge importance and will necessitate re-writing the textbooks in the field.

Principal Investigator: Dr Andrew Parnell
Local Contact: Dr Christy Kinane
Experimenter: Dr Rachel Kilbride
Experimenter: Professor Richard Jones
Experimenter: Dr Stephanie Burg

DOI: 10.5286/ISIS.E.RB2200025

ISIS Experiment Number: RB2200025

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Dr Andrew Parnell et al; (2022): The 10 nm liquid-like layer in thin polymer films does not exist, reflectivity can prove it, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2200025

Data is released under the CC-BY-4.0 license.