Thermal properties and surface reactivity in simulated body fluid of new strontium ion-containing phosphate glasses.

In this paper, we investigate the effect of SrO substitution for CaO in 50P2O5-10Na2-(40-x)CaO-xSrO glass system (x from 0 to 40) on the thermal and structural properties and also on the glass reactivity in simulated body fluid (SBF) in order to find new glass candidates for biomedical glass fibers. The addition of SrO at the expense of CaO seems to restrain the leaching of phosphate ions in the solution limiting the reduction of the solution pH. We observed the formation of an apatite layer at the surface of the glasses when in contact with SBF. SrO and MgO were found in the apatite layer of the strontium ion-containing glasses, the concentration of which increases with an increase of SrO content. We think that it is the presence of MgO and SrO in the layer which limits the leaching of phosphate in the solution and thus the glass dissolution in SBF.

Planar waveguides formed by Ag+-Na+ ion exchange in nonlinear optical glasses: diffusion and optical properties.

All-optical communication systems are the subject of intense research related to the integration of nonlinear optical materials. In sodiocalcic borophosphate glasses that contain niobium oxide and exhibit high nonlinear optical indices, planar waveguides have been formed by a Ag(+)-Na(+) ion-exchange technique. WKB analysis has been used to characterize the diffusion profiles of silver ions exchanged in glass substrate samples chemically by an electron microprobe technique and optically by an M-line technique. These methods permit the Ag(+) penetration depth and diffusion profile shape and index profiles to be determined. The results are analyzed and discussed in relation to Ca(2+) concentration and exchange conditions in glasses. The Ag(+) diffusion in these glasses can be almost entirely controlled for index-profile engineering.