TY - JOUR A1 - Aguiar, H. A1 - Solla, E.L. A1 - Serra, J. A1 - González, P. A1 - León, B. A1 - Malz, Frank A1 - Jäger, Christian T1 - Raman and NMR study of bioactive Na2O-MgO-CaO-P2O5-SiO2 glasses N2 - The results of a structural study combining NMR and Raman spectroscopy of several melt-derived glasses in the system Na2O–MgO–CaO–P2O5–SiO2 are presented. The Raman spectra show clear changes in the Si–O–Si vibrational modes (related to the bridging oxygen atoms, BO) and also verify the presence of non-bridging oxygen atoms (NBO), also named terminal oxygens. The intensity of the Si–O–NBO stretching mode depends on the cation concentration. It can be concluded from the NMR studies that the MgO-containing samples have orthophosphate units charge-compensated by Ca2+ and Mg2+. The silicate matrix also contains both types of two-valent cations and consists of Q2 and Q1 units. Similarly, the Na2O-containing samples contain isolated orthophosphate units in a silicate matrix (Q2 and Q3 units), both charge-compensated by mixed cations Ca2+ and Na+. These experimental data were compared with theoretical parameters given by the Stevels model, which is a suitable tool for understanding bioactive behavior of these glasses. Furthermore, results of the in vitro tests carried out in simulated body fluids are presented and compared with both Raman and NMR structural data. KW - Raman KW - NMR KW - Solid state KW - Bioactive glasses KW - Glass ceramics PY - 2008 DO - https://doi.org/10.1016/j.jnoncrysol.2008.07.033 SN - 0022-3093 VL - 354 IS - 45-46 SP - 5004 EP - 5008 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-18364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Malz, Frank A1 - Aguiar, H. A1 - Solla, E.L. A1 - Serra, J. A1 - González, P. A1 - León, B. A1 - Jäger, Christian T1 - Combined structural investigations of bioactive silicate glasses N2 - The results of a combined structural characterisation (XRD, IR, NMR, SEM, TEM) of a phosphate containing Mg-Ca silicate and a phosphate containing Na-Ca silicate glass samples are presented. The structural results are also compared with in vitro tests carried out in simulated body fluids for checking bioactivity. KW - Bioactive glasses KW - Silicate glasses KW - NMR KW - Raman KW - TEM PY - 2008 SN - 1013-9826 VL - 361-363 SP - 257 EP - 260 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-16572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solla, E.L. A1 - Malz, Frank A1 - González, P. A1 - Serra, J. A1 - Jäger, Christian A1 - León, B. T1 - The Role of Si Substitution into Hydroxyapatite Coatings N2 - Silicon substituted Hydroxyapatite coatings were prepared by Pulsed Laser Deposition from targets made of mixtures of Hydroxyapatite with Si powder at different concentrations. The properties of the Si-HA coatings with several degrees of Si substitution were analyzed by different techniques such as FTIR, XRD, XPS and solid-state NMR. It was found that the Si incorporation causes an amorphization of the structure together with a loss of carbonate groups. Furthermore, the Si atoms are incorporated in the form of SiO4 4- groups, and H(PO4)2- appears as the predominant phosphate group. KW - Si substituted hydroxyapatite KW - Bioactive coatings KW - Solid state NMR KW - Pulsed laser deposition PY - 2008 SN - 1013-9826 VL - 361-363 SP - 175 EP - 178 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-16576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -