Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Polymer-assisted sol-gel process for the preparation of photostimulable core/shell structured SiO2/Zn2SiO4:Mn2+ particles

: Milde, M.; Dembski, S.; Osvet, A.; Batentschuk, M.; Winnacker, A.; Sextl, G.


Materials chemistry and physics 148 (2014), Nr.3, S.1055-1063
ISSN: 0254-0584
Deutsche Forschungsgemeinschaft DFG
Deutsche Forschungsgemeinschaft DFG
Fraunhofer ISC ()

In this study the SiO2/Zn2SiO4:Mn2+ core/shell particles with diameters of about 200 nm were prepared by a modified Pechini sol-gel method. The focus of the study was on the investigation of the shell formation mechanism and on the determination of key synthesis parameters. A precise adjustment of the particle structure is crucial for optical properties. The influence of the organic additives, the pH value of the coating solution and the annealing temperature on the properties of the resulting particles was evaluated. The roles of the influential factors were studied in detail using transmission electron microscopy, X-ray diffraction, Fourier transform infrared and nuclear magnetic resonance spectroscopy. The most homogeneous coating was achieved by employing polyethylene glycol (PEG) at a pH value of 1. The application of citric acid in combination with PEG caused the formation of inhomogeneous shells. The particles showed photoluminescence and photostimulable luminescence of increasing intensities with rising annealing temperatures (1100 degrees C). These core/shell structured particles have the potential to serve as luminescent labeling agents for biomedical applications.