Effect of electron irradiation on polypropylene and polystyrene foils studied by pattern recognition methods on electron spectroscopy data

ABSTRACT

Degradation of polypropylene (PP) and polystyrene (PS) surfaces under electron beam in ultra-high vacuum is studied by electron spectroscopy, pattern recognition, and atomic force microscopy. Effects on hydrogen, carbon sp²/sp³ content, and microstructure are quantified and correlated. Electron irradiation at 1500 eV causes hydrogen and C sp³ content decrease and surface morphology modification. Roughness changes from 29 to 15 nm on PP, whereas it remains 5 nm on PS. Decreasing C sp³ content in PP, contrary to PS, indicates C–H, C–C bonds scission and carbonization. Cross-linking predominates over carbonization in PS, confirming its better stability, in agreement with surface morphology data.

Graphical abstract

KEYWORDS:

• Electron irradiation
• material degradation
• polypropylene
• polystyrene
• electron spectroscopy surface analysis
• bond scission and cross-linking
• hydrogen content

Acknowledgments

The research was partially supported also by the MEYS and ERDF project No. CZ.02.1.01/0.0/0.0/16_019/0000778 (CAAS) (B. R.). Use of the CzechNanoLab Research Infrastructure (LM2018110) is also acknowledged (B. R.).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Declaration of Competing Interest

The authors report no declarations of interest.

Additional information

Funding

This work was supported by the Fondo Europeo de Desarrollo Regional (FEDER) [CZ.02.1.01/0.0/0.0/16_019/0000778]; Ministry of Education, Youth and Science (B.R.) [CZ.02.1.01/0.0/0.0/16_019/0000778]; CzechNanoLab Research Infrastructure [LM2018110].

Notes on contributors

Beata Lesiak

Dr. Beata Lesiak graduated at Department of Physics University of Warsaw. PhD  at the Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland (1991) on studies of carbonaceous surfaces by electron spectroscopies. Post-doctorate at Department of Chemistry, University of Cambridge, England, on diffusion of hydrogen on Rh stepped surface (1992/1993). Habilitation degree at Department of Physics and Astrophysics, University of Wrocław, Wrocław, Poland (2004) on application of elastic peak electron spectroscopy for determining electron inelastic mean free path in complex materials. Current interests are devoted to structural and chemical characterization of hybrid nanomaterials for biomedical applications within international co-operations.

Josef Zemek

Dr. Josef Zemek - Institute of Physics, Academy of Sciences of the Czech Republic; 203 publications. 4281 citations, H=32.

Petr Jiricek

Dr. Petr Jiricek graduated from Faculty of Nuclear Science and Physical Engineering, Technical University of Prague. He obtained a PhD degree at the same university in 1989. The theme of his dissertation was devoted to the in-situ measurements of the crater depth during ion sputtering. He has valuable experiences investigating the solid surfaces by synchrotron radiation obtained during his stay at Max Lab, Lund University, Sweden, and Elettra at Trieste, Italy. He has worked at the Institute of Physics, Academy of Sciences of the Czech Republic  since 1987. He is a Head of Electron Spectroscopy group now. His interest is focused on the research of solid surfaces by electron spectroscopy.

Bohuslav Rezek

Prof. Bohuslav Rezek graduated from Physics  at the Faculty of Mathematics and Physics at the Charles University in Prague in 1996. in 2001 he obtained PhD at the Czech Academy of Sciences (CAS) on the study of charge transport in silicon thin films for photovoltaics by using scanning probe techniques. After PhD he was doing research on diamond devices and interfaces in Germany, Switzerland and Japan. In 2006 he became research team leader and Purkyne Fellow at the Institute of Physics CAS. In 2015 he become a Head of Physics Depart. at the Faculty of Electrical Engineering of the Czech Technical University in Prague. In 2019 he became full professor there. His research is focused on microscopic analyses of semiconductor and organic materials towards opto-electronic and bio-electronic applications.

Adam Jóźwik

Prof. Adam Jozwik - Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences.  Faculty of Physics and Applied Informatics, University of Lodz.