Wollastonite Phases Research Articles

3D-printed silicate porous bioceramics promoted the polarization of M2-macrophages that enhanced the angiogenesis in bone regeneration.

The failure of bone regeneration has been considered as a serious problem that troubling patients for decades, most of which was resulted by the poor angiogenesis and chronic inflammation after surgery. Among multiple materials applied in the repair of bone defect, silicate bioceramics attracted researchers because of its excellent bioactivity. The purpose of this study was to detect the effect of specific bioactive glass ceramic (AP40, based on crystalline phases of apatite and wollastonite) on angiogenesis and the subsequent bone growth through the modulation of macrophages. Two groups were included in this study: control group (macrophages without any stimulation, denominated as Control) and AP40 group (macrophages incubated on AP40). This study investigated the effect of AP40 on macrophages polarization (RAW264.7) and angiogenesis in vitro and in vivo. Additionally, the changes of angiogenic ability regulated by macrophages were explored. AP40 showed excellent angiogenesis potential and the expression of CD31 was promoted through the modulation of macrophages toward M2 subtype. Additionally, the macrophages incubated on AP40 synthesized more PDGF-BB comparing to macrophages without any stimulation, which contributed to the improved angiogenetic ability of human umbilical vein endothelial cells (HUVECs). Results of in vivo studies indicated increased bone ingrowth along the implants, which indicated the potential of bioceramics for bone defect repair clinically.

Apatite–Wollastonite (AW) glass ceramic doped with B2O3: Synthesis, structure, SEM, hardness, XRD, and neutron/charged particle attenuation properties

In the study, the influence of doping apatite-wollastonite (AW) glass-ceramics (GCs) with B2O3 on the structural, physical, microstructural, and light and heavy particle interaction properties is presented. Using the solid-state reaction and the cold isostatic press method, pristine AW, 10 wt% (AW-B10), and 20 wt% (AW-B20) B2O3-doped AW GCs were prepared. The prepared GCs were subject to structural, chemical compositional, and surface morphological investigation through standard experimental processes. Furthermore, the neutron (fast and thermal) and charged radiation (electron, proton, alpha, and carbon ion) interactional parameters of the GCs were obtained through standard theoretical models and software. The density of AW (2.91 gcm−3) increases to about 2.957 and 2.986 gcm−3 as B2O3 increases to 10 and 20 wt%, respectively. The presence of boron oxide supported the wollastonite phase to remain glass and suppressed crystallisation in the AW GCs. Doping AW with B2O3 improved the interaction probabilities of the GCs with fast and thermal neutrons, electrons, protons, alpha particles, and carbon ions. B-rich AW is thus potentially useful as a target material in human tissues for boron neutron capture therapy for the management of cancer and tumours, isolating or shielding specific tissues in ion beam therapy processes, and other techniques that require the exposure of human tissues to irradiation.

Preparation of diatomite-based porous ceramics containing interlayer porous MgO by low-temperature sintering for integration of high strength and low thermal conductivity

In this work, hierarchical porous ceramics based on diatomite with both high strength and low thermal conductivity were prepared by low-temperature sintering using modified diatomite and dolomite as the main raw materials. In particular, dolomite served both as a pore-forming agent to produce CO2 gas and as a ceramic component to produce porous MgO in situ. The prepared porous ceramics exhibited a hierarchical pore structure, retaining 2–300 nm nano-pores of the diatomite itself while using dolomite decomposition to produce 1–10 µm macro-pores and porous MgO with inter-layer pore sizes of 50–300 nm. The main phases of porous ceramics were cristobalite phase, pyroxene phase, wollastonite phase and MgO phase with special structure. The effect of dolomite addition on the mechanical properties and thermal insulation of porous ceramics was investigated. It was found that the addition of 30% dolomite resulted in a porous ceramic with a porosity of 59.8% and the most favorable pore size distribution. At this time, the presence of wollastonite and pyroxene-like products in the porous ceramics contributed to the highest compressive and bending strengths of 29.66 MPa and 7.22 MPa, respectively. The lowest thermal conductivity of the porous ceramics reached 0.094 W·m−1K−1, which can be attributed to the synergistic effect of the hierarchical pores and the increasing interfacial thermal resistance. Overall, the prepared hierarchical porous ceramics exhibited great potential as an alternative material to ceramic fiber insulation in high-temperature kilns.

Calcium silicate biocomposites: effects of selenium oxide on the physico-mechanical features and their in-vitro biological assessments

Bone tissue regenerative material serves as a prospective recovery candidate with self-adaptable biological properties of bio-activation, degradability, compatibility, and antimicrobial efficacy instead of metallic implants. Such materials are highly expensive due to chemical reagents and complex synthesis procedures, making them unaffordable for patients with financial constraints. This research produced an efficient bone tissue regenerative material using inexpensive naturally occurring source materials, including silica sand and limestone. The extracted SiO2 and CaO particles (75:25 wt%) were subjected to hydrothermal synthesis (water treatment instead of chemical solvents) to produce the CaSiO3 biomaterial (code: S). Selenium oxide was doped with calcium silicate at 3, 5, and 10 wt.% to enhance its properties, yielding biocomposite materials (i.e. S3, S5, and S10). The physico-mechanical properties of these materials were investigated with x-ray diffraction, Fourier transform infrared, FESEM-EDS, and micro-universal testing machine. The results revealed that the synthesized biocomposites have a crystalline wollastonite phase with a porously fused rough surface. From structural parametric calculations, we found that the biocomposites have reduced particle size and enhanced surface area due to the influence of selenium oxide. The biocomposite S10, having high SeO2 content, attained the maximum compressive strength of 75.2 MPa. In-vitro studies of bioactivity, biodegradability, biocompatibility, and antibacterial activity were performed. At 7 and 14 d of bioactivity, the synthesized biocomposites are capable of dissolving their ions into simulated body fluid (SBF) solution to precipitate hydroxyapatite and a required Ca/P ratio of 1.69 was achieved by S3. A comparative analysis has been performed on the degradation activity in Tris-HCl and the consequent pH changes during SBF treatment. The bio-analysis revealed that the biocomposite S3 shows enhanced bioactivity through a controlled degradation rate and secured cell viability of 88% at a concentration of 100 μg ml−1. It also offers significant bacterial inhibition potency against E.coli and S.aureus bacteria.

A first-principles insight into thermodynamic and mechanical properties of Xonotlite and Wollastonite phases of high temperature geothermal well cement

This study investigates the thermodynamic and mechanical properties of two common calcium silicate phases, xonotlite (Ca6Si6O17(OH)2) and wollastonite (CaSiO3), in high temperature geothermal well cement using first-principles methods. Various properties, including thermal expansion coefficients, elastic constants, free energy, and entropy, were evaluated with the use of accurate anharmonic approximations at high temperatures. The study found that wollastonite has higher mechanical strength (97 GPa) compared to xonotlite (66 GPa) and lower thermal expansion, with decreasing values at higher temperatures. Volumetric thermal expansion coefficients were also calculated at different temperatures. These results demonstrate the potential of wollastonite as a suitable material for high-temperature cement dehydration processes.

Phase transformation and mechanical properties of new bioactive glass-ceramics derived from CaO–P2O5–Na2O–B2O3–SiO2 glass system

This work investigates the role of sintering temperature on bioactive glass-ceramics derived from the new composition CaO–P2O5–Na2O–B2O3–SiO2 glass system. The sintering behaviour of the samples’ physical, structural, and mechanical properties is highlighted in this study. The experimental results indicated that the sintering process improved the crystallization and hardness of the final product. Results from XRD and FTIR showed the existence of carbonate apatite, pseudo-wollastonite, and wollastonite phases. From the results, the bioglass-ceramics sintered at 700 °C obtained the highest densification and optimum mechanical results. It had the value of 5.34 ± 0.21 GPa regarding microhardness and 2.99 ± 0.24 MPa m1/2 concerning fracture toughness, which falls in the range of the human enamel. Also, the sintered samples maintained their bioactivity and biodegradability after being tested in the PBS medium. The bioactivity does not affect but slows down the apatite formation rate. Overall results promoted the novel bioglass-ceramics as a candidate material for dental application.

Reuse of Spent Foundry Sand in Development of Glass-Ceramic Material with Wollastonite Phase

Reuse of Spent Foundry Sand in Development of Glass-Ceramic Material with Wollastonite Phase

A WOLLASTONITE SYNTHESIZED IN THE CaCl2–Na2SiO3–H2O SYSTEM AS A MODIFIER OF ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE

This paper considers the effect of wollastonite synthesized in the CaCl2–Na2SiO3–H2O model system at a temperature of 20 ºС on the physical and mechanical properties and structure of ultrahigh molecular weight polyethylene. The possibility of optimizing the process of wollastonite synthesis is proposed, which consists in the interaction of the initial components in an aqueous solution at room temperature. The study of the synthesized powders revealed the formation of finely dispersed oval, porous particles. X-ray phase analysis of the synthesis product revealed the presence of an amorphous phase of wollastonite and calcite, which is consistent with its elemental composition. It is shown that the introduction of wollastonite into the polymer matrix leads to a significant increase in the elastic modulus by 58% and compressive strength at a relative deformation of 25% by 27% compared to unfilled ultrahigh molecular weight polyethylene. It was shown that wollastonite structures of the polymer matrix, with the formation of spherulite formations smaller than those of the original polymer. IR spectroscopy revealed the presence of new peaks belonging to the ester group in composites containing wollastonite. The presence of a new oxygen-containing peak is due to the presence of adsorbed water and oxygen molecules in the pores of wollastonite, which leads to the activation of oxidative processes during the processing of composites. It is shown that the occurrence of oxidative processes and the evaporation of adsorbed water leads to weak interfacial interaction (weak adhesion) in the boundary region between the filler and the polymer matrix. However, the occurrence of oxidative processes within the amorphous phase causes an increase in the rigidity of the material. The method of differential scanning calorimetry established a decrease in the values of the enthalpy of melting and the degree of crystallinity with the introduction of wollastonite.

Synthesis of Hydroxyapatite/Bioglass Composite Nanopowder Using Design of Experiments.

Composite scaffolds of hydroxyapatite (HAp) nanoparticles and bioactive glass (BG) were applied as an appropriate selection for bone tissue engineering. To this end, HAp/BG composite was synthesized by a hydrothermal method using Design of Experiments (DOE) with a combined mixture–process factor design for the first time. The input variables were hydrothermal temperature at three levels (i.e., 100, 140, 180 °C) as a process factor and two mixture components in three ratios (i.e., HAp 90, 70, 50; BG 50, 30, 10). The degree of crystallinity and crystal size in the composite were the output variables. XRD showed that only a small fraction of BG was crystallized and that a wollastonite phase was produced. The XRD results also revealed that incorporation of Si into the HAp structure inhibited HAp crystal growth and restricted its crystallization. The FTIR results also showed that the intensity of the hydroxyl peak decreased with the addition of silicon into the HAp structure. DOE results showed that the weight ratio of the components strongly influenced the crystal size and crystallinity. SEM and FTIR results identified the greatest bioactivity and apatite layer formation in the Si-HAp sample with an HAp70/BG30 ratio after 14 days immersion in simulated body fluid (SBF) solution, as compared to other ratios and HAp alone. Therefore, the combination of HAp and BG was able to yield a HAp/BG composite with significant bioactivity.

Synthesise and Characterization of Cordierite and Wollastonite Glass-Ceramics Derived from Industrial Wastes and Natural Raw Materials.

Industrial waste is one of the primary sources that harm the environment, and this topic has occupied many scientists on how to take advantage of these wastes or dispose of them and create a clean environment. By-pass cement dust is considered one of the most dangerous industrial wastes due to its fine granular size and its volatilization in the air, which causes severe environmental damage to human and animal health, and this is the reason for choosing the current research point. In this article, eight samples of glass–ceramics were prepared using by-pass cement dust and natural raw materials known as silica sand, magnesite, and kaolin. Then melted by using an electric furnace which was adjusted at a range of temperatures from 1550 to 1600 °C for 2 to 3 h; the samples were cast and were subjected to heat treatment at 1000 °C for 2 h based on the DTA results in order to produce crystalline materials. Various techniques were used to study the synthesized glass–ceramic samples, including differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and thermal expansion coefficient (CTE). X-ray analysis showed that the phases formed through investigated glass–ceramic samples consisted mainly of β- wollastonite, parawollastonite, diopside, anorthite, and cordierite. It was noticed that β- the wollastonite phase was formed first and then turned into parawollastonite, and also, the anorthite mineral was formed at low temperatures before the formation of the diopside mineral. SEM showed that the formed microstructure turned from a coarse grain texture to a fine-grained texture, by increasing the percentage of cordierite. It also showed that the increase in time at the endothermic temperature significantly affected the crystalline texture by giving a fine-grained crystalline texture. The linear thermal expansion measurements technique used for the studied glass–ceramic samples gives thermal expansion coefficients ranging from 6.2161 × 10−6 to 2.6181 × 10−6 C−1 (in the range of 20–700 °C), and it decreased by increasing cordierite percent.

Structural, biological investigation of metal (Fe, Cu, Ag)-ceramic composites

In the present study, five composites based on metals (Ag, Fe, Cu) and ceramic; named as 0.2 Ag, 0.2 Cu, 0.2 Fe, 0.1Ag-0.1Cu, and 0.1Ag-0.1Fe were prepared by the solid-state sintering method. Two different phases of wollastonite: β-wollastonite (JCPDS No.: 01-076-0186), and α-wollastonite (JCPDS No.:00-031-0300) were identified in all composite. The in vitro bioactivity assay performed in simulated body fluid showed the bioactive behavior of all composites except one having >0.1% Ag concentration. The antibacterial activity test was performed against two pathogenic bacteria Staph. Aureus and Staph. Epidermidis using the agar well diffusion method. Results of antibacterial assays showed that all samples showed antibacterial activity except the 0.2 Fe sample. It was observed that the addition of Ag and Cu provided the inhibitory ability to composites, 0.1Ag-0.1Cu and 0.1Ag-0.1Fe composites are regarded as an optimum composite having better bioactive and antibacterial efficacy as compared to all other composites.

Granit ve rekristalize kireçtaşı doğal taş atıklarından elde edilen kompozit malzemenin ısıl dönüşümünün incelenmesi

In this study, the usability of granite (magmatic) and recrystallized limestone (metamorphic) natural stone wastes as alternative raw materials in ceramic tile production was investigated. Based on the CaO, SiO2, and Al2O3 compounds found in waste powders, mixtures containing 65% granite and 35% recrystallized limestone (by mass) were prepared to obtain the ceramic phases of gehlenite, wollastonite and anorthite as a result of thermal transformation. The grain size of both raw materials is -149 µm (d90 = 110.957 µm). The first series samples are called natural building stone (DYT), and the second series samples, in which wood chips of 2% (by mass) -1 mm grain size are added to obtain porous material, are called natural building stone - porous (DYT-G). The samples belonging to both series was applied heat treatment at 1,160°C. Phase analysis of samples obtained after heat treatment was measured by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM-EDS) methods, and sintering properties were measured using water absorption coefficient, flexural strength, modulus of elasticity, density-porosity and color measurement tests. Gehlenite and wollastonite phases were detected in the heat treated samples, but no anorthite phase was observed. According to the test results, it was determined that the flexural strength (22.64 MPa) of the DYT marked sample was in accordance with the ceramic tile standards. In the DYT-G example, despite the decreasing unit volume mass value, it was determined that the bending strength (16.50 MPa) was in the range of ceramic tile strength values.

Synthesis and controlled drug release behavior of micro-mesoporous wollastonite nanoparticles. Effect of calcination temperature on the structural and biodegradability properties

In this study, amorphous and crystalline (Pseudowollastonite) phases of wollastonite (CaSiO3) nanoparticles were successfully synthesized by a facile soft-template method with a micro-mesoporous structure. In addition, the effect of calcination temperature on the structural properties, surface charge, and biodegradability of synthesized nanoparticles were investigated. After that, the drug loading capacity and drug release behavior of the sample calcined at the lowest calcination temperature (600 °C, MMW-600) was investigated with Epirubicin (EPI) as an anti-cancer drug. Noticeably, MMW-600 showed the most appropriate (bio) properties as a candidate of drug carrier in comparison with the samples that calcined at higher temperatures by showing: the least hydrodynamic size (85 nm), the highest specific surface area (301.68 m2g) as well as micro-and mesopore volumes as 0.075 and 0.282 cm3g, respectively. Moreover, it indicated the lowest thickness of the pore wall (6.73 nm) and the highest rate of biodegradation in Tris-HCl. The investigation of drug release behavior revealed a pH-controlled release due to the pH-dependent surface charge of micro-mesoporous wollastonite (MMW) nanoparticles, which was demonstrated by Zeta potential analysis. Additionally, MMW nanoparticles demonstrated a desired high rate and sustained release of EPI (44% and 80% after 4 and 70 h, respectively) in succinate buffer (pH 5.5, mimic the pH of a tumor site). In conclusion, MMW can be a great candidate as a pH-controlled release drug-nanocarrier for anti-cancer drug delivery systems.

Accelerated Weathering and Carbonation (Mild to Intensified) of Natural Canadian Silicates (Kimberlite and Wollastonite) for CO2 Sequestration

Canada’s mineral reserves can play a very important role in curbing climate change if natural alkaline minerals are used for the process of mineral carbonation. In this work, the potential of using two Canadian natural silicates for accelerated carbonation is experimentally assessed: kimberlite mine tailing (Mg0.846Al0.165Fe0.147Ca0.067SiO3.381) from the Northwest Territories, and mined wollastonite ore (Ca0.609Mg0.132Al0.091Fe0.024SiO2.914) from Ontario. The aim of this work was to evaluate the weathering reactivity and CO2 uptake capacity via carbonation of these two comminuted rocks, both of which are made up of a mixture of alkaline minerals, under process conditions that spanned from milder to intensified. Research questions addressed include: does kimberlite contain a sufficient amount of reactive minerals to act as an effective carbon sink; is dehydroxylation necessary to activate kimberlite, and to what extent does it do this; do secondary phases of wollastonite hinder its reactivity; and can either of these minerals be carbonated without pH buffering, or only weathered? Incubator, slurry, and pressurized slurry methods of accelerated weathering and carbonation were used, and the effect of the process parameters (temperature, solid-to-liquid ration, reaction time, CO2 level, pH buffer) on the CO2 uptake and crystalline carbonates formation is tested. The reacted samples were analyzed by pH test, loss-on-ignition test, calcimeter test, and X-ray diffraction analysis. Results showed that wollastonite ore (rich in fast-weathering CaSiO3) is more suitable for accelerated carbonation than kimberlite tailing (containing slow-weathering hydrated magnesium silicates and aluminosilicates) when only its capability to rapidly form solid carbonates is considered. Incubator and pressurized buffered slurry methods proved to be most effective as under these conditions the precipitation of carbonates was more favorable, while the unbuffered slurry reaction conditions were more akin to accelerated weathering rather than accelerated carbonation.

Crystal Structure and Thermal Behaviour of Calcium Monosilicate Derived from Calcined Chicken Eggshell and Rice Husk Ash

This study focuses on the synthesis of synthetic calcium monosilicate ceramic from chicken eggshells and rice husks waste through the mechanochemical route that relatively straightforward without adding any binders. Synthetic calcium monosilicate was mixed using a 1:1 ratio of calcined eggshell and rice husk ash, which both materials known as rich in calcium oxide and silica sources, respectively. The mixed powder was pressed using uniaxial pressing before fired at 1100°C, 1150°C, 1200°C, 1250°C, and 1300°C for 120 minutes with a heating rate of 5°C/min. The XRD spectrum from 1100°C to 1200°C mainly consists of pseudowollastonite (ICSD: 98-005-2576), wollastonite and silicon dioxide phases. However, as the sintering temperature increases, the wollastonite phases was completely transformed into pseudowollastonite, leaving some unreacted silica.

Effect of zinc oxide on wollastonite: Structural, optical, and mechanical properties

Partial substitution of ZnO for CaO in the wollastonite formula was performed via wet precipitation. The effects of ZnO/CaO replacement on the structure, porosity, morphology, optical, and mechanical properties of the CaO–SiO2 ceramic were examined. Structural results and Fourier transform infrared (FTIR) spectra indicated the existence of mixed phases of wollastonite with hardystonite and willemite with hadystonite composites, depending on the ZnO content. The calculated crystallite size confirmed that the formed composites were in the nanoscale range. The FTIR results verified the mixed phases of the prepared samples. The optical band gap energy (Eg) values of 3.3 and 4.56 eV referred to the willemite phase in samples with high ZnO content. Addition of ZnO increased the bulk density and decreased the porosity of the wollastonite. The reduced porosity controlled the mechanical behavior of the prepared composites. The maximum stress (σu) increased from ∼4.10 to ∼26.68 N/mm2 as the porosity decreased from 52.20% to 40.17% for a ZnO content increased from 0% to 50%. The fracture load increased with the ZnO content. The degradability of samples revealed that the higher the ratio of ZnO to the nominal wollastonite, the more influential it was on the degree of weight loss % and the variation in the pH value. The bioactivity test estimated that all samples surface exposed development of a newly formed apatite layer, consequently evidencing the bioactivity of the prepared ceramic composites. Therefore, such substitution can be used in vital applications.

Sintering behaviour of fluorapatite–silicate composites produced from natural fluorapatite and quartz

In this work, the sintering behaviour of fluorapatite (FAp)–silicate composites prepared by mixing variable amounts of natural quartz (2.5 wt% to 20 wt%) and FAp was studied. The composites were pressureless sintered in air at temperatures from 1000 °C to 1350 °C. The effects of temperatures on the densification, phase formation, chemical bonding and Vickers hardness of the composites were evaluated. All the samples exhibited mixed phase, comprising FAp and francolite as the major constituents along with some minor phases of cristobalite, wollastonite, dicalcium silicate and/or whitlockite dependent on the quartz content and sintering temperature. The composite containing 2.5 wt% quartz exhibited the best sintering properties. The highest bulk density of 3 g/cm3 and a Vickers hardness of >4.2 GPa were obtained for the 2.5 wt% quartz–FAp composite when sintered at 1100 °C. The addition of quartz was found to alter the microstructure of the composites, where it exhibited a rod-like morphology when sintered at 1000 °C and a regular rounded grain structure when sintered at 1350 °C. A wetted grain surface was observed for composites containing high quartz content and was believed to be associated with a transient liquid phase sintering.

Mixed alkali effect in SiO2-CaO-Al2O3-TiO2-R2O (R = Li, Na) glass ceramics

The effects of Li2O/(Li2O + Na2O) ratio and temperature on structure, crystallization, microstructure and mechanical properties of SiO2-CaO-Al2O3-TiO2-9 mol% R2O glass ceramics were investigated by melting-sintering method. It was concluded that as substituting Li2O for Na2O, the degree of polymerization of glass first increased and then decreased by Raman spectra analysis. The activation energy of crystallization was in the range of 165–193 kJ/mol, and the crystallization behavior was dominated by bulk crystallization. When the glass samples were heat treated at 750 ℃, only glass containing 9 mol% Li2O crystallized, and the crystalline phases were β-quartz solid solution and wollastonite phases; while when heat treatment temperature increased to 800 ℃ or 850 ℃, the main crystal phase changed from granular wollastonite to fine-grained β-spodumene phase as replacing Na2O by Li2O. In addition, both the flexural strength and Vickers hardness first increased and then decreased with the increase of Li2O/(Li2O + Na2O) ratio.

Influence of SiO2, Al2O3, CaO, and Na2O on the elevated temperature performance of alkali‐activated treated palm oil fuel ash‐based mortar

AbstractThe mechanical, physical, and chemical changes due to oxides molar ratios (SiO2/Al2O3 and SiO2/CaO), and various Na2O concentrations of treated palm oil fuel ash (TPOFA)‐based alkali‐activated mortar (AAM) after being exposed to different elevated temperatures up to 1,000°C were investigated. The source materials (SMs) and alkaline activator (AA) were used as the main base material to produce the AAM. The SMs consist of TPOFA with and without mineral additives (Ca(OH)2, Al(OH)3, and silica fume (SF)). The AA was characterized by various Na2O concentrations of 7.1, 6.0, and 5.5% relative to the AAB weight. The results indicated that the relative compressive strength (CS) improved significantly from 9.20 to 34.62% after being exposed to 800°C. This was mainly due to the decrease in the total oxide's ratio of SiO2/Al2O3 and SiO2/CaO from 14.84 and 6.98% to 4.27 and 2.03%, respectively. The relative CS has increased from 0.0 to 101.38% after exposed to 1,000°C when Na2O concentration reduced from 7.1 to 5.5%. This was due to the formation of more N–A–S–H and C–A–S–H gel binders as indicated at 28 days, which were transformed to nepheline (NaAl(SiO4)) and wollastonite (CaSiO3) phases after exposure to 800°C and 1,000°C, respectively.

Synthesis and characterization of samarium doped calcium soda–lime–silicate glass derived wollastonite glass–ceramics

Samarium doped wollastonite based glass–ceramics, Sm3+:CaSiO3 were prepared from conventional melt-quench in water technique, derived CaO–SLS precursor glass system with empirical formula [Sm2O3]y[21CaO–79SLS]100-y where y = 0, 1, 2, 3, 4 and 5 wt.% by a control solid-state sintering process. The effect of Sm2O3 concentration and sintering temperature on the density, crystal growth, and morphology of Sm3+:CaSiO3 was examined by bulk density measurement, XRD, FESEM micrograph, and FTIR spectroscopy. The density of glass and glass–ceramic samples show an increasing trend with the increase of samarium concentration and sintering temperature. The amorphous nature of precursor glasses has been proven by the XRD pattern. FTIR spectra suggest that samarium reacts as a modifier in the glass matrix. Also, with the increase in samarium concentration, the structural units in the glass matrix might be changed. The XRD, FESEM, and FTIR results display the generation of the wollastonite phase in the CaO–SLS glass matrix. Besides, the optical band gap energy (Eg) of the glass and glass–ceramics were decreased with the increase of Sm2O3 concentration. This decreasing trend occurs due to the scattering of light by the Sm3+:CaSiO3 crystals. The overall result promoted the Sm3+:CaSiO3 has high potential to use as concrete materials in the construction industry.