Structural analysis and devitrification of glasses based on the CaO–MgO–SiO2 system with B2O3, Na2O, CaF2 and P2O5 additives

Effect of copper addition on glass transition of silicate–phosphate glasses

“…The effect of copper addition on this part of the spectrum was not very noticeable. On the other hand, the very weak band at 454 cm -1 for 0Cu6P glass sample could be attributed to symmetric stretching of O-P-O bending modes of the orthophosphate PO 4 3-units (Q 0 ) which shifted towards lower wavenumber with the increasing content of CuO in the glass structure, indicating depolymerization of the phosphate network [13].…”

Sol-gel bioactive glass-ceramics Part II: Glass-ceramics in the CaO-SiO2-P2O5-MgO system

“…The presence of the absorption bands at 910 cm -1 (Ca-1 sample) with small intensity can be ascribed to the presence of Si 2 O 7 structure [32], which is in accordance with XRD data. The peak with low intensity at 485 cm -1 (for Ca-2 sample) suggests a high degree of modification to the silicate network [16].…”

“…In the FTIR spectra, the bands corresponding between 1022 (1033) cm , together with 479 (485) cm -1 bands can be assigned to the vibration of the Si-O-Si bond [16,30]. The absorption bands near 950 and 900 cm -1 (for Ca-1 and Ca-2 samples) have been assigned to ν as SiO -bonds in silicate tetrahedral units with 2 and 3 non-bridging oxygens [16].…”

“…The absorption bands near 950 and 900 cm -1 (for Ca-1 and Ca-2 samples) have been assigned to ν as SiO -bonds in silicate tetrahedral units with 2 and 3 non-bridging oxygens [16]. On the other hand, the absorption band envelope in 800-1200 cm -1 frequency is well defined at lower frequencies upon the polymerization of silicate network [31].…”

“…The obtained material demonstrates a higher flexural strength, fracture toughness, and a high in vitro bioactivity [15]. When B 2 O 3 , Na 2 O, and CaF 2 were used as additives, Agathopoulos et al [16] studied that the presence of diopside and wollastonite were dominated, but weak peaks, assigned to akermanite and fruorapatite were also registered. Apatite and the mica crystalline phases are observed by others [17].…”