title: In Situ Nanocalorimetric Investigations of Plasma Assisted Deposited Poly(ethylene oxide)-like Films by Specific Heat Spectroscopy.
abstract: In recent years, highly cross-linked plasma polymers have started to unveil their potential in numerous biomedical applications in thin-film form. However, conventional diagnostic methods often fail due to their diverse molecular dynamics conformations. Here, glassy dynamics and the melting transition of thin PEO-like plasma assisted deposited (ppPEO) films (thickness 100 nm) were in situ studied by a combination of specific heat spectroscopy, utilizing a pJ/K sensitive ac-calorimeter chip, and composition analytical techniques. Different cross-linking densities were obtained by different plasma powers during the deposition of the films. Glassy dynamics were observed for all values of the plasma power. It was found that the glassy dynamics slows down with increasing the plasma power. Moreover, the underlying relaxation time spectra broaden indicating that the molecular motions become more heterogeneous with increasing plasma power. In a second set of the experiment, the melting behavior of the ppPEO films was studied. The melting temperature of ppPEO was found to decrease with increasing plasma power. This was explained by a decrease of the order in the crystals due to formation of chemical defects during the plasma process.
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM) , Unter den Eichen 87, 12205 Berlin, Germany.
authors.forename: Sherif
authors.initials: S
authors.lastname: Madkou
authors.affiliation: Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University in Prague , V Holesovickach 2, 18000 Prague 8, Czech Republic.
authors.forename: Iurii
authors.initials: I
authors.lastname: Melnichu
authors.affiliation: Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University in Prague , V Holesovickach 2, 18000 Prague 8, Czech Republic.
authors.forename: Andrei
authors.initials: A
authors.lastname: Choukourov
authors.affiliation: Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University in Prague , V Holesovickach 2, 18000 Prague 8, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Krakovsky
authors.affiliation: Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University in Prague , V Holesovickach 2, 18000 Prague 8, Czech Republic.
authors.forename: Hynek
authors.initials: H
authors.lastname: Biederman
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung (BAM) , Unter den Eichen 87, 12205 Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schönhals
mesh_terms: D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D006358:Hot Temperature; D008970:Molecular Weight; D036103:Nanotechnology; D044367:Phase Transition; D058626:Plasma Gases / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000032:analysis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D058626:Plasma Gases; D011092:Polyethylene Glycols