XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
207
T1: P–74
Bioactive layers based on phosphorus modified black glasses
Magdalena Gawęda
1
, Piotr Jeleń
1
, Elżbieta Długoń
1
, Maciej Sitarz
1
1
Department of Silicate Chemistry and Macromolecular Compounds, Faculty of Materials Science
and Ceramics, AGH University of Science and Technology, 30 Mickiewicza Av., 30-059 Krakow,
Poland, e-mail: mgaweda@agh.edu.pl
Black glasses are amorphous materials based on silicon oxycarbide. They might be obtained
by ceramization of the proper polymeric precursors. The most effective path to obtain black
glasses in the form of thin layers is to deposit precursors on a metallic substrate in the form of
the ladder like silsesquioxanes (substrates require proper pretreatment, such like degreasing,
removing of the passivation layer, but not require special roughness of the surface). Such
compounds might be obtained by the sol-gel method. It was reported before, this route is highly
effective and leads to the formation of homogenous, hermetic, continuous layers of black glasses
[e.g. 1, 2]. Obtained layers have good adhesion, thermal and chemical stability in aggressive
environments. They are resistant to the corrosion and durable. It is possible to elevate properties
of black glasses by doping with various ions [e.g. 3]. Modifications with aluminium or nitrogen
ions cause improvement of mechanical properties. Doping with boron ions prevents tendency of
the material to crystallization. Another ion, which may have a positive impact on the silicon
oxycarbide based materials is phosphorus. Black glasses without any modifications are already
bioactive, but this property might be developed by doping with phosphorus - the natural
compound of the human bones.
This work is focusing on the formation of phosphorus doped black glasses layers of
enhanced bioactivity. The aim was to discover the route of the substitution of phosphorus ions
into the ladder-like silsesquioxanes and ceramized black glass. Two different organophosphorus
precursors were proposed (triethyl phosphate and triethyl phosphite) and two different paths of
the synthesis examined. Both bulk materials and layers were examined using numerous of
spectroscopic and microscopic methods: middle infrared spectroscopy (MIR), Raman
spectroscopy, energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM).
Bioactivity of the obtained layers was examined using the so-called Kokubo test [4]. Samples
were kept in the stimulated body fluid (SBF) for the specified time. Results of the analyses
enable both development of the optimum synthesis and evaluation of the black glasses as the
possible material for medicine.
Keywords: silicon oxycarbide; biomaterial; bioactivity; ceramic coatings; sol-gel
Acknowledgments
This work was supported by the NCN project “Functional layers of black glasses based on ladder-like
silsesquioxanes 2014/15/B/ST8/02827”.
References
[1] M. Sitarz, W. Jastrzębski, P. Jeleń, E. Długoń, M. Gawęda, Spectroch. Acta A 132 (2014) 884.
[2] P. Jeleń, M. Bik, M. Nocuń, M. Gawęda, E. Długoń, M. Sitarz, J. Mol. Struct. 1126 (2016) 172.
[3] A.M. Wootton, M. Rappensberger, M.H. Lewis, S. Kitchin, A.P. Howes, R. Dupree, J. Non-Cryst.
Solids 204 (1996) 217.
[4] T. Kokubo, H. Takadama, Biomaterials 27 (2006) 2907.
XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
208
T1: P–75
Spectroscopic studies of hybrid nano-SiO
2
and SiOC coatings
Piotr Jeleń
1
, Elżbieta Długoń
1
, Magdalena Gawęda
1
, Maciej Sitarz
1
1
Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 30
Mickiewicza Av., 30-059 Krakow, Poland, e-mail: pjelen@agh.edu.pl
Silicon oxycarbide based coatings are well-known from their stability, good mechanical
properties and corrosion resistance. It is due to their unique structure, which may be compared
with the structure of amorphous silica in which carbon ions exist as the anionic substitution
replacing oxygen ions. This leads to the densification of the glass matrix and causes
improvement of the properties of the material. In this work, SiOC coatings (also called black
glasses) are obtained with the use of polymeric precursors – ladder like silsesquioxanes [1, 2].
These compounds are synthesised via the sol-gel method. They were chosen because of the
presence of silicon-carbon bond in their structure and effortless deposition on any surface.
During the study on the layer formed directly on the surface of the austenitic steel, diffusion of
the ions from the alloy into the coating during the ceramization process was reported. To prevent
this phenomenon, the formation of the transition layer of nano-SiO
2
was proposed [3]. This
inner layer was deposited on the steel substrate with the use of electrophoretic deposition
process (EPD) and subsequently went under high temperature treatment [4]. In the second step,
the outer layer of silsesquioxanes was deposited via dip-coating method and caramized. It was
desired to prevent especially iron ions from the diffusion to the layer of SiOC. This path enabled
the formation of the hybrid nano-SiO
2
/ SiOC coating.
Detailed structural and microstructural analysis enabled to describe processes occurring in
the obtained material. Infrared and Raman spectroscopy analysis combined with X-ray
diffractometry allowed a detailed study on the nature of the connections between steel and nano-
SiO
2
and between nano-SiO
2
and SiOC. Moreover, alterations of the glass structure were
analysed. Scanning electron microscopy permitted description of the hybrid coating
morphology.
Keywords: nano-SiO
2
; silicon oxycarbide; spectroscopy; hybrid layer; EPD; sol-gel
Acknowledgments
This work was supported by the NCN project “Functional layers of black glasses based on ladder-like
silsesquioxanes 2014/15/B/ST8/02827”.
References
[1] M. Sitarz, W. Jastrzębski, P. Jeleń, E. Długoń, M. Gawęda, Spectrochim. Acta A 132 (2014) 884.
[2] P. Jeleń, M. Bik, M. Nocuń, M. Gawęda, E. Długoń, M. Sitarz, J. Mol. Struct. 1126 (2016) 172.
[3] Sh. Ammar, K. Ramesh, B. Vengadaesvaran, S. Ramesh, A.K. Arof, Electrochim. Acta 220 (2016)
417.
[4] M.F. De Riccardis, Ceramic Coatings – Applications in Engineering, 2012.
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