scholarly journals Influence of calciumphosphate-silicate glass-ceramic materials on the capability to bind albumin in vitro and in vivo biocompatibility

2020 ◽  
Vol 11 (2) ◽  
pp. 250-260
Author(s):  
O. V. Savvova ◽  
◽  
V. M. Shimon ◽  
O. V. Babich ◽  
O. I. Fesenko ◽  
...  
Keyword(s):  
Silicate Glass ◽  
Glass Ceramic ◽  
Ceramic Materials ◽  
Glass Ceramic Materials

Fabrication of Bioactive Glass-Ceramics by Selective Laser Sintering

2006 ◽  
Vol 309-311 ◽  
pp. 289-292
Author(s):  
Ruth D. Goodridge ◽  
Chikara Ohtsuki ◽  
Masanobu Kamitakahara ◽  
David J. Wood ◽  
Kenny W. Dalgarno
Keyword(s):  
Glass Ceramic ◽  
Selective Laser Sintering ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Laser Sintering ◽  
Layer Manufacturing ◽  
Custom Made ◽  
Good Potential

The feasibility of processing glass-ceramics using the layer manufacturing technique, selective laser sintering (SLS), to produce parts with suitable biological and mechanical properties for use in bone replacement applications, has been investigated. Glass-ceramics derived from glasses based on several different systems have been considered. Initial experiments using an apatite-mullite glass-ceramic (4.5SiO2⋅3Al203⋅1.6P2O5⋅3CaO⋅2CaF2) demonstrated the ability to process glass-ceramic materials using this technique, creating parts with a strength similar to that of cancellous bone, and a porous structure that was shown in vivo to be suitable for the ingrowth of bone. Concerns over the inability of the apatite-mullite material to form an apatite layer on its surface when soaked in a simulated body fluid (SBF) has led to the development of Al2O3-free glasses based on the systems (50-x)CaO⋅45SiO2⋅5P2O5⋅xCaF2 and (48-x)CaO⋅45SiO2⋅5P2O5⋅2CaF2⋅xNa2O. These materials have demonstrated good in vitro bioactivity, and therefore have good potential as candidates for processing by an indirect SLS method for the production of custom-made bone implants.

scholarly journals Alumina silicate glass-ceramic materials for electrical purposes

2020 ◽  
Vol 120 ◽  
pp. 174-185
Author(s):  
O. V. Savvova ◽  
G. K. Voronov ◽  
S. A. Ryabinin ◽  
E. Yu. Fedorenko ◽  
V. D. Timofeev
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Electrical Properties ◽  
Silicate Glass ◽  
Glass Ceramic ◽  
Breakdown Strength ◽  
Chemical Properties ◽  
Ceramic Materials ◽  
Silicate System ◽  
Glass Ceramic Materials

The prospects for use of glass-ceramic materials as electrical products were analyzed. The priority of a self-organized macro- and nanostructure formation of the glass-ceramic materials under conditions of low-temperature heat treatment to ensure their high physical and chemical properties was shown. The choice of an alumina silicate system of materials for obtaining high-strength glass-ceramic materials with improved electrical properties was substantiated, taking into account the aspects of energy saving. The technological modes of cooking, forming and heat treatment of glass-ceramic materials were determined. Resistance, dielectric constant and dielectric loss tangent at 106 Hz were measured using an E6-13A teraometer on a trielectrode system at a temperature of +29 °C and a DE-5000 RLC meter. Electric strength (Em) and cold crushing strength were determined according to GOST 24409-80. Tensile strength according to GOST 32281.1-2013 (EN 1288-1: 2000). The decisive influence on the electrical properties of glass-ceramic materials the crystalline phases of α-cordierite, β-spodumene or lithium disilicate, as well as the residual glass phase composition has been established. The structure influence of the alumina silicate glass-ceramic materials on the provision of their electrical (tgδ∙104 = 70 ÷ 80; ε = 8.0 ÷ 9.3 (at f = 106 Hz); lg ρv = 12.9 ÷ 15.0 (ρv, Ohm·cm at Т = 20 °C) and mechanical (K1C = 3.15 ÷ 4.3 МPа∙м1/2; σ comp = 630 ÷ 700 МPа, σbend = 300 ÷ 350 МPа; KCU = 4.8 ÷ 5.9 kJ/m2) properties. It was found that, the defining condition for the developed glass-ceramic materials use as insulating materials under repeated exposure to high-temperature operations is their high breakdown strength Em = 37 ÷ 42 MV/m and thermal shock resistance due to low TCLE (α∙107 = 21.5 ÷ 31.8 deg-1). The influence of phase composition and structure of the alumina silicate glass-ceramic materials on their electrical and mechanical properties was analyzed. A comparative assessment of the known ceramic and glass-ceramic materials for electrical purposes has made it possible to establish the feasibility of using the developed materials as substrates in the design of a hybrid integrated circuit, vacuum-tight shell and capacitor dielectrics.

New Silicate Glass-Ceramic Materials and Composites

2010 ◽  
Vol 68 ◽  
pp. 1-12 ◽  
Author(s):  
Dachamir Hotza ◽  
Antonio Pedro Novaes de Oliveira
Keyword(s):  
Silicate Glass ◽  
Glass Ceramic ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Crystalline Phases ◽  
Glass Ceramic Materials ◽  
Thermal And Electrical Properties ◽  
Large Production

New silicate glass-ceramic compositions have been investigated due to their interesting chemical, mechanical, thermal, and electrical properties. LZSA glass-ceramics based on -spodumene (Li2O•Al2O3•4-10SiO2) and zircon (ZrSiO4) crystalline phases have shown good chemical resistance, high bending strength as well as high abrasion resistance, when compared with traditional ceramic materials, and coefficient of thermal expansion from 4.6 to 9.110-6 °C-1. These features basically depend on the nature, size and distribution of the formed crystals as well as on the residual glassy phase. The nature of the formed crystalline phases and consequently the final properties can be controlled by modifying the chemical composition of the parent glass and also by adequate selection of the heat-treatment parameters. The classical fabrication of glass-ceramic materials consists on the preparation of monolithic glass components followed by heat treatments for crystallisation. However, this technology requires high investments and can be justified only for large production. A viable alternative could be the production of glass-ceramics processed from glass powders and consolidated by sintering using the same equipments of traditional ceramic plants. This work reports the manufacturing and characterization of glass-ceramic materials and composites processed by pressing, injection moulding, extrusion, casting, replication, and rapid prototyping.

scholarly journals Combination of Na-Ca-phosphate and fluorapatite in wollastonite-diopside glass-ceramic: degradation and biocompatibility

2021 ◽  
Author(s):  
Ebrahim A. Mahdy ◽  
Hanaa Y. Ahmed ◽  
Mohammad Farag
Keyword(s):  
Calcium Phosphate ◽  
Cell Viability ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Vero Cells ◽  
Crystalline Phases ◽  
Sodium Calcium ◽  
Glass Ceramic Materials

Abstract In this study, we investigated the effect of introducing sodium calcium phosphate (NCP), fluorapatite (FA), or the combination of both phases in the wollastonite-diopside (WD) bioactive glass-ceramic system on the crystalline phases formed, microstructure, degradation, and biocompatibility of those materials. The prepared materials were characterized by DTA, XRD, and SEM/EDX. Moreover, the density was measured via Archimede’s method, and the mechanical properties were measured by Vicker’s microhardness indenter. The in vitro bioactivity test was carried out in the simulated body fluid (SBF), and the cell viability test was evaluated using the Vero cells. The results showed that the formed crystalline phases were close to the starting proposed phases. Moreover, NCP-containing WD glass-ceramic was showed the lowest density value due to its low densification, and accordingly, it showed the lowest Vicker`s microhardness value due to the same reason. Furthermore, combining sodium calcium phosphate in WD glass-ceramic was increased cell viability better than that included fluorapatite, whereas, the combination of both crystalline phases in WD glass-ceramic led to an increase in the cytotoxicity to the highest value. In conclusion, different properties of wollastonite-diopside glass-ceramics can be tailored by the combination of NCP or FA, and hence, these glass-ceramic materials can be modified effectively according to the purpose for which it is intended to be applied. The obtained results indicated that different properties of WD glass-ceramic materials can be tailored by the combination of NCP and/or FA. Hence, these glass-ceramics are expected to be useful materials in promising biomedical applications, such as orthopedics and dentistry.

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