Premium
Vacuum‐ultraviolet Photochemically Initiated Modification of Polystyrene Surfaces: Chemical Changes ¶ , ‡
Author(s) -
LópezGejo Juan,
Gliemann Hartmut,
Schimmel Thomas,
Braun André M.
Publication year - 2005
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2005.tb01442.x
Subject(s) - polystyrene , surface modification , chemistry , irradiation , fourier transform infrared spectroscopy , ultraviolet , analytical chemistry (journal) , photochemistry , infrared , excimer laser , mass spectrometry , excimer , materials science , laser , chemical engineering , polymer , organic chemistry , chromatography , optics , physics , optoelectronics , nuclear physics , engineering
Fourier‐Transform infrared (FTIR) spectroscopy and surface energy analysis (contact angle measurements) have been performed as a means of identification and quantification of the functionalization of polystyrene surfaces upon vacuum ultraviolet‐ (VUV‐) photochemically initiated oxidation. Photochemical oxidation was performed in the presence of water vapor and molecular oxygen using a pulsed Xe 2 ‐excimer radiation source (λ exc : 172 nm). Surface oxidation was studied as a function of two parameters: irradiation time and distance between sample and radiation source. During the first 1–2 min of irradiation, an increase of the concentrations of hydroxyl (OH) and carbonyl (C=O) groups on the surface was observed, both reaching limiting values. As expected, the rate of oxidation diminished exponentially with increasing distance between the radiation source and the surface of the polystyrene film. Changes in the surface energy due to the introduction of these polar ( i.e. OH and C=O) groups were also determined. The densities of the functional groups decreased upon washing with acetonitrile, and analysis of the washing solution by means of gas chromatography‐mass spectrometry (GC‐MS) revealed the presence of a large number of products. The application of pulsed Xe 2 ‐excimer radiation sources as a valuable alternative to conventional means ( i.e. laser and plasma) for the photochemical oxidation and surface modification of polystyrene is discussed.