A Spectroscopic Investigation into the Setting and Mechanical Properties of Titanium Containing Glass Polyalkenoate Cements

Titanium (Ti) implants are extensively used in a number of biomedical and dental applications. This work introduces Ti into the glass phase of a zinc-based glass polyalkenoate cement (GPC) and investigates changes in handling and mechanical properties considering two molecular weight polyacrylic acids (PAA), E9 and E11. Considering the handling properties, the working time (Tw) increased from 50 sE9, 32 sE11 (BT 101, Ti-free) to 169 sE9, 74 sE11 with TW-Z (highest Ti content), respectively. The setting time (Ts) increased from 76 sE9, 47 sE11 (BT 101) to 303 sE9, 232 sE11 with TW-Z, respectively. Ti was also found to have a significant increase on both compressive (σc) and biaxial flexural strength (σf), where σc increased from 36 MPaE9, 56 MPaE11 (BT 101) to 56 MPaE9 and 70 MPaE11 with TW-Z respectfully. σf also increased from 11 MPaE9, 22 MPaE11 (BT 101) to 22 MPaE9 and 77 MPaE11 with TW-Z, respectively. No increase in mechanical properties was evident with respect to maturation. Raman Spectroscopy was employed to investigate changes in glass structure and the setting of the cements with. This revealed increased glass network disruption with increasing TiO2 content and matured cement setting with TW-Z as compared to the control BT 101. FT-IR was then employed to investigate any additional setting mechanism and changes with time. Spectroscopy determined that Ca2+/Sr2+PAA complexes are primarily responsible for the setting and mechanical strength with no changes occurring over time

The Structural Role of Titanium in Ca-Sr-Zn-Si/Ti Glasses for Medical Applications

Glasses for medical applications are used in particulate form or as a cement component. This work was undertaken to determine structural changes in 0.48SiO2-0.36ZnO-0.12CaO-0.04SrO glass when the SiO2 is substituted with 5 mol% increments of TiO2. X-ray Diffraction (XRD) was used to determine the presence of crystallinity. This occurred after additions of 20 mol% TiO2. Differential Thermal Analysis (DTA) and Network connectivity (NC) calculations determined that by increasing the TiO2 content, the Tg and NC reduced (Tg 670 °C to 632 °C, NC 1.83 to -1.14) suggesting that TiO2 acts as a modifying oxide. X-ray Photoelectron Spectroscopy (XPS) was used to determine the glass composition and the relative fraction of Bridging Oxygens (BO) to Non-Bridging Oxygens (NBO). XPS revealed that by increasing the concentration of TiO2, the NBO concentration increases, further suggesting the modifying role of Ti. The NBO/BO ratio was found to increase from 1.2 to 9.0 as the TiO2 content increased from 0 to 20 mol% additions. Raman spectroscopy was used to determine the Q-Structure of the glass series and found that the addition of TiO2 reduced the Raman shift from containing predominantly Q1/Q2 units when no Ti was present to Q0/Q1 with TiO2 additions. © 2010 Elsevier B.V. All rights reserved

A spectroscopic investigation into the setting and mechanical properties of titanium containing glass polyalkenoate cements

Titanium (Ti) implants are extensively used in a number of biomedical and dental applications. This work introduces Ti into the glass phase of a zinc based Glass Polyalkenoate Cement (GPC) and investigates changes in handling and mechanical properties considering two molecular weight polyacrylic acids (PAA), E9 and E11. Considering the handling properties, the working time (Tw) increased from 50s E9, 32s E11 (BT 101, Ti-free) to 169s E9, 74s E11 with TW-Z (highest Ti content) respectively. The setting time (Ts) increased from 76s E9, 47s E11 (BT 101) to 303s E9, 232s E11 with TW-Z respectively. Ti was also found to have a significant increase on both compressive (σc) and biaxial flexural strength (σf), where σc increased from 36 MPa E9, 56 MPa E11 (BT 101) to 56 MPa E9 and 70 MPa E11 with TW-Z respectfully. σf also increased from 11 MPa E9, 22 MPa E11 (BT 101) to 22 MPa E9 and 77 MPa E11 with TW-Z respectively. No increase in mechanical properties was evident with respect to maturation. Raman Spectroscopy was employed to investigate changes in glass structure and the setting of the cements with. This revealed increased glass network disruption with increasing TiO2 content and matured cement setting with TW-Z as compared to the control BT 101. FT-IR was then employed to investigate any additional setting mechanism and changes with time. Spectroscopy determined that Ca2+/Sr2+PAA complexes are primarily responsible for the setting and mechanical strength with no changes occurring over tim

Americium and trivalent Lanthanides incorporation in high-level waste glass-ceramics

International audienceThe incorporation and partitioning of americium and trivalent lanthanides were investigated in aluminoborosilicate glass-ceramics with apatite-like silicate crystals of general formula Ca$_2$(Ln,Am)$_8$(SiO$_4$)$_6$O$_2$. A microstructural and structural study of two glass-ceramics containing Am$_2$O$_3$ - La$_2$O$_3$ or Nd$_2$O$_3$ - La$_2$O$_3$, respectively, was carried out by XRD, SEM-EDS and EMPA so as to assess a comparison of Lanthanides and Actinides partitioning into apatite crystals and residual glass. Moreover, Raman analyses of residual glasses were performed to compare the role of Am and Nd on the glassy structure. Results put forward that shape, composition, Ln-Am stoichiometry and cell parameters of apatite crystals of both (Am-La) and (Nd-La) glass-ceramics are very close. This paper thus shows similar results for (Am-La) and (Nd-La) glass-ceramics in terms of apatite - glass partitioning and in terms of structural role on glassy structure. It can be therefore put forward that Nd$^{3+}$ and Am$^{3+}$ behaviors are close, either in the glass or in the crystalline structure