title: Laser-induced optical breakdown spectroscopy of polymer materials based on evaluation of molecular emission bands.
abstract: Laser-induced breakdown spectroscopy (LIBS) for composition analysis of polymer materials results in optical spectra containing atomic and ionic emission lines as well as molecular emission bands. In the present work, the molecular bands are analyzed to obtain spectroscopic information about the plasma state in an effort to quantify the content of different elements in the polymers. Polyethylene (PE) and a rubber material from tire production are investigated employing 157nmF2laser and 532nm Nd:YAG laser ablation in nitrogen and argon gas background or in air. The optical detection reaches from ultraviolet (UV) over the visible (VIS) to the near infrared (NIR) spectral range. In the UV/VIS range, intense molecular emissions, C2Swan and CN violet bands, are measured with an Echelle spectrometer equipped with an intensified CCD camera. The measured molecular emission spectra can be fitted by vibrational-rotational transitions by open access programs and data sets with good agreement between measured and fitted spectra. The fits allow determining vibrational-rotational temperatures. A comparison to electronic temperatures Tederived earlier from atomic carbon vacuum-UV (VUV) emission lines show differences, which can be related to different locations of the atomic and molecular species in the expanding plasma plume. In the NIR spectral region, we also observe the CN red bands with a conventional CDD Czerny Turner spectrometer. The emission of the three strong atomic sulfur lines between 920 and 925nm is overlapped by these bands. Fitting of the CN red bands allows a separation of both spectral contributions. This makes a quantitative evaluation of sulfur contents in the start material in the order of 1wt% feasible.
authors.affiliation: Institute of Applied Physics, Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Trautner
authors.affiliation: Institute of Applied Physics, Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria; Department of Organic Chemistry, Charles University in Prague, Hlavova 2030/8, 128 43 Prague 2, Czech Republic; Center for Laser Applications, The University of Tennessee Space Institute, Tullahoma, TN 37388-9700, USA.
authors.forename: Juraj
authors.initials: J
authors.lastname: Jasik
authors.affiliation: Center for Laser Applications, The University of Tennessee Space Institute, Tullahoma, TN 37388-9700, USA.
authors.forename: Christian G
authors.initials: CG
authors.lastname: Parigger
authors.affiliation: Institute of Applied Physics, Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria.
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Pedarnig
authors.affiliation: KRAIBURG Austria GmbH & Co. KG, 5132 Geretsberg, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Spendelhofer
authors.affiliation: KRAIBURG Austria GmbH & Co. KG, 5132 Geretsberg, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Lackner
authors.affiliation: Department of Experimental Physics, Physics and Informatics, Comenius University, Mlynska dolina F2, 842 48 Bratislava, Slovakia.
authors.forename: Pavel
authors.initials: P
authors.lastname: Veis
authors.affiliation: Institute of Applied Physics, Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria. Electronic address: johannes.heitz@jku.at.
authors.forename: Johannes
authors.initials: J
authors.lastname: Heitz
keywords: LIBS; Laser-induced breakdown spectroscopy; Molecular emission spectroscopy; Polyethylene; Rotational-vibrational analysis; Rubber from tire production