| Autor: |
Maibohm, C., Brewer, J. R., Sturm, H., Balzer, F., Rubahn, H.-G. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 9/1/2006, Vol. 100 Issue 5, p054304, 6p, 2 Color Photographs, 2 Black and White Photographs, 1 Diagram, 8 Graphs |
| Abstrakt: |
Degradation of nanofibers made from organic molecules such as para-hexaphenylene or functionalized quaterphenylene via photoexcitation or thermal irradiation is investigated by optical and morphological studies. Under ambient air conditions and in the limit of strong excitation, the degradation of luminescence intensity is accompanied by an increasing surface roughness of the aggregates and by material depletion. Whereas the luminescence intensity is decreasing exponentially with increasing illumination time, the material removal follows a linear relationship. Ablation can be stopped and bleaching can be slowed down by irradiating the nanofibers in vacuum or by coating them with a few hundred nanometers thick layer of silicon oxide (SiOx). Since the latter treatments do not completely stop the bleaching, it is concluded that bleaching of nanofibers involves at least three independent processes, namely, intramolecular configuration change, photo-oxidation, and material removal. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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