Physicochemical Analysis of the Polydimethylsiloxane Interlayer Influence on a Hydroxyapatite Doped with Silver Coating

Abstract

We investigate by different complementary methods the processes occurring when a polydimethylsiloxane film is used as interlayer for a silver doped hydroxyapatite coating. The X-ray diffraction and Fourier Transform Infrared Spectroscopy measurements show that the hydroxyapatite doped with silver is in a crystalline form and someSiO44-ions formation takes place at the surface and in the bulk of the new hydroxyapatite doped with silver/polydimethylsiloxane composite layer. The possibility ofSiO44-ions incorporation in the structure of silver doped hydroxyapatite by the mechanism ofSiO44-/PO43-ions substitution is analysed. The new formed silver doped hydroxyapatite/polydimethylsiloxane composite layer is compact, homogeneous, with no cracks as it was shown by Scanning Electron Microscopy and Glow Discharge Optical Emission Spectrometry.

The Effect of the Ionizing Radiation on Hydroxyapatite–Polydimethylsiloxane Layers

“…A detailed spectral analysis of the unirradiated HAp:PDMS composite layers was presented in previous studies . The interactions that appear between the HAp chemical bonds with those specific to PDMS were investigated and elucidated in our anterior studies . In our studies on “physicochemical analysis of the PDMS interlayer influence on a HAp doped with silver coating” , we have demonstrated that the SiO 4 4− , ions can be incorporated into the HAp structure substituting the PO 4 3− ions from the structure of HAp.…”

“…Figure and Table present the IR spectra and the IR bands assignment of irradiated and unirradiated HAp:PDMS samples. A detailed spectral analysis of the unirradiated HAp:PDMS composite layers was presented in previous studies . The interactions that appear between the HAp chemical bonds with those specific to PDMS were investigated and elucidated in our anterior studies .…”

“…The PDMS layers have been obtained in atmospheric pressure corona discharge starting from liquid precursors on Ti substrates. The HAp powder was deposited by thermal evaporation technique on Ti substrates previously covered with PDMS layers .…”

The effect of functional ions (Y3+, F−, Ti4+) on the structure, sintering and crystallization of diopside-calcium pyrophosphate bioglasses

“…The increase in T g with addition of Yttrium to glass can be explained by the higher fraction of Si\ \O\ \P linkages, as has been deduced from FTIR spectra in Fig. 5, where the bands at 675 and 780 are attributed to the Si\ \O\ \P bending of octahedral silica rather than tetrahedral Si\ \O\ \Si [47,48]. The trend of T g can be explained by taking into account that, according to Ray [49], the glass transformation temperature depends on the density of covalent cross-linking and the number and strength of the cross-links between the cation and oxygen atoms.…”

“…The in-vitro biomineralization activity in simulated body fluid (SBF) was assessed as described elsewhere [31] using glass powders, which 0.5 mmol L −1 ) is nearly equivalent to that of human plasma [47,48]. The powder-SBF mixtures were immediately sealed into sterilized plastic flasks and were placed in an oven at 37 ± 0.5°C.…”