Properties of Sm₂O₃─Al₂O₃─SiO₂ Glasses for In Vivo Applications

Abstract

297ChemInform Abstract Sm2O3-Al2O3-SiO2 (SmAS) glasses are investigated in order to assess their usefulness as radiotherapeutic agents. Below 1600 rc C, glass formation occurs in the compositional range 9-25 mol% Sm2O3, 10-35 mol% Al2O3, and 40-75 mol% SiO2. The density, refractive index, microhardness, and thermal expansion coefficient of the glasses increases as the Sm2O3 content increases from 9 to 25 mol%, the values exceeding those reported for fused silica. The chemical durability of the glasses is high in deionized water at 37 rc C and 70 rc C, but is lower in 1 N HCl at 37 rc C. The SmAS glasses are sufficiently durable and chemically inert for time periods beyond the effective radiotherapeutic life of 153Sm, and therefore, they should be acceptable for radiotherapeutic applications. An excellent starting composition is 14 Sm2O3•16 Al2O3•70 SiO2 (mol%), which has the highest chemical durability in deionized water at 37 rc C.

Thermochemistry of rare-earth aluminate and aluminosilicate glasses

“…Previous investigations of rare-earth aluminosilicate glasses focused on their glass-forming regions [12] and specific physical properties [13,14] such as hardness, elastic constants and chemical durability as refractory glasses [15,16]. An overview of phase relationships of the RE 2 O 3 -Al 2 O 3 -SiO 2 systems was given by Kolitsch et al [17] for RE ¼ La, Ce, Nd, Gd, Y, Yb and Sc.…”

Phase diagram estimation of the Al2O3-SiO2-Re2O3 systems

“…Extensive studies were concentrated at the physical properties and high Received Jun. 24, 1999;Revised Sep. 5, 1999 Supported by State Key Lab of High Performance Ceramics and Superfine Micro-structure (9517 and 9708) temperature behavior of these substances [1][2][3][4][5][6] . In order to describe the stable and metastable equilibrium be- and Nesor [7], Du, Jin and Huang [14] conducted the thermodynamic evaluation of binary oxide systems and calculated ternary isothermal sections, projection of liquidus with Bonnier's method.…”

Directional solidification, thermo-mechanical and optical properties of (Mg_xCa_1-x)_3Al_2Si_3O_12 glasses doped with Nd^3+ ions

“…Among them, rare-earth aluminosilicate and calcium aluminosilicate glasses have been studied for many years due to their high elastic modulus and hardness, high refraction index, high thermal conductivity, high glass transition temperature, excellent optical properties and good corrosion resistance [4][5][6][7][8][9][10][11]. Moreover, they are known for their ability to accommodate high concentration of rare-earth active ions such as Nd 3+ or Er 3+ as well as their low phonon energy due to the aluminate network.…”

“…Moreover, they are known for their ability to accommodate high concentration of rare-earth active ions such as Nd 3+ or Er 3+ as well as their low phonon energy due to the aluminate network. These properties have led to various applications in solid state lasers, optical waveguides, luminescence probes, and even in medicine as in vivo radiation delivery vehicles for cancer treatment of internal organs [4]. Among the possible rare-earth ions, neodymium has been studied in a large variety of glasses due to its potential applications in the field of infrared optical amplification related to the radiative efficiency of the 4 F 3/2 → 4 I 11/2 emission at around 1.06 μm [12].…”