New 92S6 mesoporous glass: Influence of surfactant carbon chain length on the structure, pore morphology and bioactivity

International audienceThe main objective of the present work was to investigate the effect of surfactant chain length on the structure, porosity and bioactivity of 92S6 (92% SiO2, 6% CaO, and 2% P2O5 mol%) mesoporous sol-gel glasses. The aim was to provide a basis for controlling the porosity of the glass to obtain a control of bioactive behavior. A series of mesoporous bioactive glasses were synthesized using three different surfactants (C10H20BrN, C19H42BrN, C22H48BrN). Surfactant type dependence on the textural properties, particularly porosity and bioactivity were studied. Result indicate that the bioactivity factors were improved by a short surfactant carbon length

Excess entropy and thermal behavior of Cu- and Ti-doped bioactive glasses

International audienceBioactive glasses belong to the ceramic family. They are good materials for implantation due to their excellent capacities to create an intimate bond with bones. Copper is known for its anti-inflammatory, antibacterial, and antifungal properties. Titanium is biocompatible and resistant to corrosion. These chemical elements can be introduced in bioactive glasses to provide a wide variety of uses and to enhance the physiological properties of implanted biomaterials. In this work, bioactive glasses doped with different contents of copper and titanium were synthesized by the melting method. The purpose is to study the effect of doping metal element on the thermal characteristics (T g, T c, and T f). The results revealed that the increase of the content of copper and titanium in the glass matrix decreases the melting temperature and induces an increase of the thermal stability. The excess entropies of pure and doped glasses were calculated. Obtained results highlighted the decrease of the excess entropy with the increase of metal elements contents

Comparative Study of Nanobioactive Glass Quaternary System 46S6

International audienceDifferent bioactive glass systems have been prepared by sol-gel. However, the production of Na2O-containing bioactive glasses by sol-gel methods has proved to be difficult as the sodium nitrate used in the preparation could be lost from the glass structure during filtration and washing. The aim of this study was to prepare the quaternary system 46S6 of bioactive glass by modified sol-gel techniques with a decrease in the time of gelation. In addition, compare the behaviour of the prepared sol-gel bioactive glass system by its corresponding prepared by melting. The obtained glasses were characterized by using several physicochemical techniques; XRD, FTIR, TEM and SEM beside the effect of the glass particles on the viability of osteoblast like cells (Saos-2). Results show that nanopowders 40-60 nm of 46S6 glass system had been prepared by modified sol-gel (acid-base reaction) method at 600°C in just three days at 600°C. Cell viability by MTT assay confirmed the effectiveness of the prepared nanobioactive glass

Influence of Synthesis Parameters on the Structure, Pore Morphology and Bioactivity of a New Mesoporous Glass

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Reactivity kinetics of sol-gel derived 52S4 glass versus the treatment temperature

International audienceThis work is devoted to study the reactivity of the quaternary glass 52S4 (52% SiO2–30% CaO–14% Na2O–4% P2O5 (wt%)), synthesized by sol-gel process versus the treatment temperature. The dried gel was heat treated at 600 and 650 °C and soaked in simulated body fluid (SBF). XRD results confirm the amorphous character of glass treated at 600 °C even though the heat treatment at 650 °C induces Na2Ca2Si3O9 formation. After soaking in SBF, SEM and EDS results show the formation of carbonated hydroxyapatite (CHA) at the glass surface for both temperatures. For the glasses treated at 600 and 650 °C, two phenomena were observed: the glass dissolution in SBF and the CHA precipitation, but the reactivity kinetics of glass was different when temperature changes. For SGDG600, the CHA began to crystallize after 16 h. For SGDG650, a glass ceramic made of a glassy matrix and of Na2Ca2Si3O9, the crystallized carbonated HA was observed after 2 h. In addition, a new crystallization at the glass surface of Na2Ca2Si3O9 was observed after 15 days

Reactivity kinetics of 52S4 glass in the quaternary system SiO2-CaO-Na2O-P2O5: Influence of the synthesis process: Melting versus sol-gel

International audienceA new composition of bioactive glass, in the quaternary system SiO2-CaO-Na2O-P2O5, was synthesized using melting and sol-gel routes. The prepared glass, 52S4: (wt.%) 52% SiO2-30% CaO-14% Na2O-4% P2O5, was soaked in Simulated Body Fluid (SBF) in order to evaluate the kinetic reactivity of this glass versus the synthesis mode. The obtained results have shown that 52S4 is a bioactive glass if it is prepared either by melting or sol-gel methods. The bone-like apatite was formed at the glass surface prepared by sol-gel route after 2 h. However, the formation of this apatite was delayed to 1 day when the glass was prepared by melting method. In addition, this apatite was crystallized, after 30 days soaking in SBF, only if the glass is prepared by melting route. The glass prepared by sol-gel method was more resorbable and leads to silica gel formation up on amorphous apatite layers at any time. So, this silica gel inhibited the crystallization of amorphous apatite

Investigation of the surfactant type effect on characteristics and bioactivity of new mesoporous bioactive glass in the ternary system SiO2-CaO-P2O5: Structural, textural and reactivity studies

International audienceIn this study, a mesoporous bioactive glass 92S6 (92% SiO2, 6% CaO, and 2% P2O5), was successfully prepared using two different surfactants. The template was further removed by calcination to generate unorganized or well-ordered pores. The bioactive glass was characterized by wide angle X-ray diffraction (WAXRD) analysis, small angle X-ray diffraction (SAXRD) analysis, Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). From the isotherm desorption branch, the surface area was determined using the Brunauer-Emmett-Teller (BET) method, while pore volume and pore size distribution were determined by the Barrett-Joyner-Halenda (BJH) method. The in vitro bioactivity tests were also conducted in simulated body fluid (SBF). Finally, the samples were analyzed to quantify the apatite formation ability when soaked in SBF solution. The evolutions of silicon (Si), phosphorus (P) and calcium (Ca) concentrations in SBF were evaluated by inductively coupled plasma optical emission spectrometry (ICP-OES). The SAXRD and TEM studies evidence the influence of the structure-directing agent (ionic surfactant CTAB or non-ionic P123) in the generation of unorganized or well ordered pores in the sol-gel synthesis of a bioactive glass in the ternary system SiO2-CaO-P2O5. As observed from small-angle XRD patterns and TEM images, the presence of non-ionic surfactant and subsequent calcination lead to the formation of highly ordered mesoporous glass. The better textural properties observed in the "ordered mesoporous glasses" compared to those of "non-ordered mesoporous glasses" lead to a faster in vitro bioactivity kinetics

Investigation of the surfactant type effect on characteristics and bioactivity of new mesoporous bioactive glass in the ternary system SiO2-CaO-P2O5: Structural, textural and reactivity studies

International audienceIn this study, a mesoporous bioactive glass 92S6 (92% SiO2, 6% CaO, and 2% P2O5), was successfully prepared using two different surfactants. The template was further removed by calcination to generate unorganized or well-ordered pores. The bioactive glass was characterized by wide angle X-ray diffraction (WAXRD) analysis, small angle X-ray diffraction (SAXRD) analysis, Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). From the isotherm desorption branch, the surface area was determined using the Brunauer-Emmett-Teller (BET) method, while pore volume and pore size distribution were determined by the Barrett-Joyner-Halenda (BJH) method. The in vitro bioactivity tests were also conducted in simulated body fluid (SBF). Finally, the samples were analyzed to quantify the apatite formation ability when soaked in SBF solution. The evolutions of silicon (Si), phosphorus (P) and calcium (Ca) concentrations in SBF were evaluated by inductively coupled plasma optical emission spectrometry (ICP-OES). The SAXRD and TEM studies evidence the influence of the structure-directing agent (ionic surfactant CTAB or non-ionic P123) in the generation of unorganized or well ordered pores in the sol-gel synthesis of a bioactive glass in the ternary system SiO2-CaO-P2O5. As observed from small-angle XRD patterns and TEM images, the presence of non-ionic surfactant and subsequent calcination lead to the formation of highly ordered mesoporous glass. The better textural properties observed in the "ordered mesoporous glasses" compared to those of "non-ordered mesoporous glasses" lead to a faster in vitro bioactivity kinetics

Sol-gel synthesis of a new composition of bioactive glass in the quaternary system SiO2-CaO-Na2O-P2O5

International audienceNew sol-gel exptl. conditions were tested to prep. a new SiO2-based bioactive glass with high Na2O content. The aim of this work is to investigate the real influence of the synthesis route (sol-gel vs. melting) on the glass intrinsic properties and then, later, on the glass behavior and particularly on bioactivity. The obtained glass and its melt derived counterpart were characterized from structural and morphol. (porosity, sp. surface area) point of view. It could be noticed that the synthesis mode has no significant influence on glass structure. Conversely, the synthesis mode greatly influences the glass texture. The sol-gel derived glass exhibits a greatly higher sp. surface area and pore vol. than melt derived glass. This parameter may be a key factor of glass bioactivity