Strontium Phosphate Research Articles

Evaluation of Cytotoxicity and Characterization of Strontium Phosphate–Chitosan Nanoparticle Coating on Magnesium for Bioimplant Applications: A Preliminary In Vitro Study

Evaluation of Cytotoxicity and Characterization of Strontium Phosphate–Chitosan Nanoparticle Coating on Magnesium for Bioimplant Applications: A Preliminary In Vitro Study

Enhancing the luminescent properties of strontium phosphate glass via controlled crystallization and rare earth dopants

The study focused on investigating the photoluminescence behavior of pure strontium phosphate glasses with a composition of 62.5% P2O5 and 37.5% SrO. Then it was extended to investigate the effects of adding rare earth elements (Pr3+, Sm3+, Eu3+, Dy3+) and the crystallization process on improving luminescent properties of the parent glass. Various spectroscopic measurements, including XRD, SEM & EDAX, and FTIR, were conducted to examine the relationship between structural changes and their impact on luminescent performance. The optical measurements showed a characteristic enhancement resulting from the addition of RE3+-dopants and the crystallization process. The crystallization of glasses yielded a single phase from Sr(PO3)2 with an extended emission peak at 671 nm and heightened intensity compared to the glassy sample. The development of efficient and stable luminescent glasses via crystallization and dopant type can lead to advancements in applications such as glowing devices, optical detectors, and photonics innovations.

Effect of strontium phosphate coating on NCM811 powders for high-performance Li-ion battery cathode

The NCM811 cathode material, characterized by a high nickel content, is known for its substantial energy capacity but is afflicted by challenges, including electrolyte degradation and inadequate cyclic stability. In this study, a chemical bath deposition technique is utilized to apply a layer of Sr3(PO4)2 material onto the surface of NCM811 particles to address these problems. This procedure yields a continuous protective coating that shields the NCM811 particles from detrimental interactions with the electrolyte, such as HF attack and the formation of surface cracks, while also promoting the diffusion of lithium ions during charge/discharge cycles. XRD analysis indicated that the application of Sr3(PO4)2 coating did not cause any changes in the structure of the NCM811 cathode material. SEM images of all coated samples demonstrated that all coated samples have spherical morphology. Additionally, both Raman and FTIR examinations provide evidences supporting the existence of strontium phosphate material on the surface of the NCM811 cathode material. The distinctive 5.9 nm-thick Sr3(PO4)2 coating enables the NCM811 material to maintain 96 % of its capacity after 100 charge/discharge cycles in a voltage range of 2.8–4.4 V vs. Li/Li+ at a current rate of 1C.

Titanium-doped phosphate glasses containing zinc and strontium applied in bone regeneration

Phosphate bioactive glass has been studied for its advanced biodegradability and active ion release capability. Our previous research found that phosphate glass containing (P2O5)–(Na2O)–(TiO2)–(CaO)–(SrO) or (ZnO) showed good biocompatibility with MG63 and hMSCs. This study further investigated the application of 5 mol% zinc oxide or 17.5 mol% strontium oxide in titanium-doped phosphate glass for bone tissue engineering. Ti-Ca-Na-Phosphate glasses, incorporating 5% zinc oxide or 17.5% strontium oxide, were made with melting quenching technology. The pre-osteoblast cell line MC3T3-E1 was cultured for indirect contact tests with graded diluted phosphate glass extractions and for direct contact tests by seeding cells on glass disks. The cell viability and cytotoxicity were analysed in vitro over 7 days. In vivo studies utilized the tibial defect model with or without glass implants. The micro-CT analysis was performed after surgery and then at 2, 6, and 12 weeks. Extractions from both zinc and strontium phosphate glasses showed no negative impact on MC3T3-E1 cell viability. Notably, non-diluted Zn-Ti-Ca-Na-phosphate glass extracts significantly increased cell viability by 116.8% (P < 0.01). Furthermore, MC3T3-E1 cells cultured with phosphate glass disks exhibited no increase in LDH release compared with the control group. Micro-CT images revealed that, over 12 weeks, both zinc-doped and strontium-doped phosphate glasses demonstrated good bone incorporation and longevity compared to the no-implant control. Titanium-doped phosphate glasses containing 5 mol% zinc oxide, or 17.5 mol% strontium oxide have promising application potential for bone regeneration research.Graphical

Surface Characterization of Strontium Phosphate Coating on Magnesium for Bioimplant Applications: A Preliminary In Vitro Study

Surface Characterization of Strontium Phosphate Coating on Magnesium for Bioimplant Applications: A Preliminary In Vitro Study

Physical and luminescence properties of Ce3+ activated strontium phosphate glasses

Strontium phosphate (SrO–P2O5–Al2O3–Gd2O3) glasses with 0.05, 0.1, 0.5, and 1 mol % CeO2 were prepared by the conventional melt quenching technique. These glasses' luminescence, scintillation, and physical properties were measured and discussed in detail. The density, refractive index, and oxygen packing density of the studied glasses were increased with an increase in CeO2 concentration. At lower concentrations of CeO2, the characteristic 310 nm emission from Gd3+ and broadband emission from Ce3+ ions were obtained under X-ray excitations. The intensity of both Gd3+ and Ce3+ emission bands under 270 nm Gd3+ excitations reduced with further increase in CeO2, showing the delayed energy transfer from Gd3+ to Ce3+ ions. The integrated X-ray-induced luminescence intensity of 0.5% CeO2 glass was found to be 21% that of reference BGO crystal. For the lower concentration of CeO2, a slow decay time along with the fast Ce3+ decay was observed and disappears for higher CeO2 concentrations. The fast luminescence decay in the range of 22 ns–30 ns was observed for all the PSAG:Ce glasses, which was attributed to the lifetime of the 4f-5d transition of the Ce3+ ions. The faster decay time and reasonable scintillation light suggest the application of these glasses for radiation detector applications.

Janus Membrane with Intrafibrillarly Strontium-Apatite-Mineralized Collagen for Guided Bone Regeneration.

Commercial collagen membranes face difficulty in guided bone regeneration (GBR) due to the absence of hierarchical structural design, effective interface management, and diverse bioactivity. Herein, a Janus membrane called SrJM is developed that consists of a porous collagen face to enhance osteogenic function and a dense face to maintain barrier function. Specifically, biomimetic intrafibrillar mineralization of collagen with strontium apatite is realized by liquid precursors of amorphous strontium phosphate. Polycaprolactone methacryloyl is further integrated on one side of the collagen as a dense face, which endows SrJM with mechanical support and a prolonged lifespan. In vitro experiments demonstrate that the dense face of SrJM acts as a strong barrier against fibroblasts, while the porous face significantly promotes cell adhesion and osteogenic differentiation through activation of calcium-sensitive receptor/integrin/Wnt signaling pathways. Meanwhile, SrJM effectively enhances osteogenesis and angiogenesis by recruiting stem cells and modulating osteoimmune response, thus creating an ideal microenvironment for bone regeneration. In vivo studies verify that the bone defect region guided by SrJM is completely repaired by newly formed vascularized bone. Overall, the outstanding performance of SrJM supports its ongoing development as a multifunctional GBR membrane, and this study provides a versatile strategy of fabricating collagen-based biomaterials for hard tissue regeneration.

Effect of Precursor Solution on Sedimentation of Alkaline-earth Phosphates at Different Temperatures

Kinetic study of sedimentation of alkaline-earth phosphates-magnesium phosphate (MP), calcium phosphate (CP), strontium phosphate (SP) and barium phosphate (BP) precipitates was carried out by varying reactant concentration approach involving turn-wise variation of precursor metal ions (Mg2+, Ca2+, Sr2+ and Ba2+) and phosphate ion (PO43-) concentrations, and monitoring the settling of the precipitate formed in a precipitate sedimentation measurement apparatus. A pseudo-rate order equation, associated with the approach of varying reactant concentration, was linearized, and the dependence of precipitate sedimentation on precursor concentration, established therewith. Whereas MP precipitate gave positive order-sedimentation increased with increase in concentrations of precursor solutions, orders of CP, SP and BP precipitates were negative-sedimentation decreased with increase in concentrations of precursor solutions. Inter-particle attraction and repulsion associated with high solid concentration, volume of precipitate particles formed as well as chemical interactions of precipitate with the mother solution might have caused these effects.

Study on the effect of bismuth oxide on the structural, optical and dielectric properties of strontium phosphate glasses

ABSTRACT The melt-quenching technique was used to prepare strontium phosphate glasses with bismuth oxide. The impact of replacing Bi3+ with Sr2+ on density (d), molar volume (Vm), and glass transition temperature (Tg) was investigated. The FTIR spectra revealed that the structural units of the samples consisted of [BiO3], [BiO6], [PO3], and [PO4]. UV-visible spectroscopy was used to study the optical transmittance, energy band gap (Eopt), and Urbach energy (Etail). The Wemple-Didomenico model successfully described the dispersive behavior of the refractive index. Impedance spectroscopy is utilized to determine the electrical and dielectric properties. The AC conductivity followed Jonscher's universal power law, and it was observed that as the concentration of Bi2O3 increased, the frequency exponent (s) decreased. The dielectric constant (ϵ’) and dielectric loss (tan δ) were found to be frequency and composition dependent. The parameters describing the dispersion of dielectric constant are obtained through the Cole-Davidson relation.

The Influence of pH Value on the Microstructure and Properties of Strontium Phosphate Chemical Conversion Coatings on Titanium.

Strontium (Sr) is a trace element in the human body that can promote bone formation and inhibit bone absorption. A conversion coating of strontium phosphate (Sr-P) on the surface of titanium (Ti) can improve its biological properties and has many potential applications in the fields of dentistry and orthopedics. In the present study, Sr-P coatings with SrHPO4 and Sr3(PO4)2 crystals on Ti are prepared by a phosphate chemical conversion (PCC) treatment and the effect of pH values on the properties of the Sr-P coatings is researched. The results prove that the phase composition, morphology, and corrosion resistance of the coated Ti vary according to the pH values of the PCC solution. The morphology of the conversion deposition on Ti changes from plat-like to cluster-like and then to homogeneous microcrystals as the pH value changes from 2.50 to 3.25. Only discrete SrHPO4 crystals are generated on the substrate at lower pH values, while relatively stable Sr3(PO4)2 and SrHPO4 crystals grow and subsequently form an integrated coating on the Ti as the pH exceeds 2.50. The cross-sectional morphologies and bonding strength of different coatings are also researched. The corrosion resistance of coated Ti improves compared with that of bare Ti because of the Sr-P coatings with a Sr3(PO4)2 phase. In addition, it is indicated that the Sr-P coatings on Ti can improve the adhesion and differentiation of BMSCs.

Strontium phosphate/functionalized carbon nanofiber composite: A promising electrode material for amperometric detection of flufenamic acid

Anti-inflammatory drug pollution and its potentially disastrous consequences have recently emerged as a major health issue worldwide because of its widespread use in inadequate environments. Among, Flufenamic acid (FFA) is a class of anti-inflammatory drugs widely used for therapeutic treatments, and its over usage causes severe issues in the biological systems. In this work, a particle–like strontium phosphate (Sr2P2O7) was prepared. The efficiency was increased by making a composite with functionalized carbon nanofiber (F-CNF) and used to detect FFA. The prepared individual materials (Sr2P2O7 and F-CNF) and the composite (Sr2P2O7@F-CNF) were confirmed by various spectroscopy techniques. The electrochemical studies of Sr2P2O7@F-CNF were done by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A sensitive i-t amperometry technique was used for the determination of FFA. The attained results show that Sr2P2O7@F-CNF shows a higher active surface area (A= 0.197 cm2), a wide linear range of 0.001–80.8 µM, a low detection limit of 0.9 nM, and higher selectivity. Finally, the Sr2P2O7@F-CNF was taken to the real-time analysis with the water and urine samples. The result shows an acceptable recovery range of ± 97.50–99.66 % for the water and urine samples.

First examination of the influence of Y3+ ions on the structural, physical and optical properties of strontium phosphate glasses

First examination of the influence of Y3+ ions on the structural, physical and optical properties of strontium phosphate glasses

Activity of Nickel Supported Over Nanorod-Shaped Strontium Hydroxyapatite Catalysts in Selective Methanation of CO & CO2

Nickel modified strontium hydroxyapatite (Ni/Sr-HAP) supported catalysts are studied in selective methanation of CO/CO2. In this work, a new type of nano rod-shaped strontium hydroxyapatite-based catalysts with two different sizes and aspect ratios were prepared by sol–gel method and in next step, Ni precursor was wet impregnated i.e., denoted as Ni/Sr-HAP and Ni/Sr-HAP(F127). The catalytic tests were performed in CO and CO2 methanation reactions and evaluated the light-off temperatures curves (225–450 °C) under ambient pressure in a fixed-bed flow reactor. The physicochemical properties of the prepared catalysts were characterized by XRD, N2 physisorption, TEM, SEM, TPR, CO2/H2-TPD and H2-chemisorption techniques. From XRD analysis, both Ni/Sr-HAP and Ni/Sr-HAP(F127) were identified as the hydroxyapatite type structure with high crystallinity and very low intensity peaks corresponds to strontium phosphates as the main phase and structure. The TEM and SEM micrographs of Ni/Sr-HAP catalysts displayed a nano- rod shaped morphology with different dimensions and exhibited average Ni particle size of ~ 9.2 nm. While Ni/Sr-HAP(F127) shown the rod size in the length in the range of 100–250 nm and width in the range of 20–40 nm with average Ni particle size 5.7 nm. The F127 mediated support Sr-HAP synthesis i.e., Ni/Sr-HAP(F127) mesoporous catalyst possessed higher metal surface with smaller Ni particles size and possessed higher CO2 adsorption capacity. The medium strength basic sites of Ni/Sr-HAP catalyst played an important role in methanation reactions. Based on the characterization and the catalysts activity results, small sized nanorods of Ni/Sr-HAP(F127) is the most active and selective catalyst due to the higher Ni dispersion, higher amounts of medium basic sites, and reducibility character than the bigger nanorods based Ni/Sr-HAP catalyst.

Structural, physical, thermal and optical spectroscopy studies of the europium doped strontium phosphate glasses

The europium-doped strontium phosphate glasses are attractive for numerous applications, including lasers, light-emitting diode displays, photonic devices, optoelectronics, and solar cells. In the present study, we have focused on discovering the effect of the europium (Eu3+) dopant on the structural, physical, thermal, and optical properties of the strontium phosphate glasses. In this study, pure and europium-doped strontium phosphate glasses were synthesized by a conventional melt quenching method. Their structural and optical characterizations were performed through X-ray diffraction (XRD), Fourier transforms infrared (FTIR), TGA, DTA, and photoluminescence. All of the glasses produced are amorphous, according to XRD measurements. FTIR showed that the addition of the europium content to the strontium phosphate glasses led to their depolymerization. This is what led to the shrinking of metaphosphate units and was followed by an increase in the number of pyrophosphate species. The study of the physical properties was evaluated from the measured density values. According to the progressive increase in the europium concentration, it was discovered that the density increased from 2.059 to 2.082 g/cm3, while the molar volume values reduced from 62.441 to 62.083 cm3/mol. The thermal measurements confirm that the prepared glasses have good thermal stability with a lower variation of the transition temperature Tg, which is varied between 422 and 429°C. Photoluminescence spectroscopy showed that all samples present the strongest emission peak, which is obtained at 611 nm (red) for the 5D0→7F2 transition. The prepared PSrEux glasses could potentially be used for laser, LED and photonic devices.

Effect of Bi2O3 on the physical, structural and gamma ray shielding properties of phosphate glasses inside the ternary P2O5-SrO-Bi2O3 system

Strontium phosphate glasses containing bismuth oxide were prepared using conventional melt-quenching technique. X-ray diffraction and differential scanning calorimetry (DSC) analysis suggests that stable ternary glasses of composition 70 P2O5-(30-x)SrO-xBi2O3 can be obtained for x = 5–25 mol%. This study examines such physical properties as the density, molar volume (Vm), glass transition temperature (Tg), and structural properties in the interest of explaining the effect on these glasses of Bi-Sr substitution. An almost linear increase in the density when the concentration of bismuth increases between x = 5 and x = 10 mol% followed by monotonic decreasing is noted. However, the calculated molar volume (Vm) behaves in exactly the opposite way. DSC curves showed that the glass transition temperature (Tg) decreases by 555 °C down to 490 °C as the concentration of Bi2O3 increases, due to the increase in the number of bridging oxygens. Structural investigations performed using IR spectroscopy revealed that the structure of the phosphate network contains predominately meta-phosphate (Q2) units, with contributions from pyrophosphate (Q1) and orthophosphate (Q0). The infrared spectra also revealed depolymerization of the phosphate chains in the glass system, with increased Bi2O3 concentration and the formation of P–O–Bi bonds. The study of the gamma ray shielding parameters showed that the prepared glasses can be used for shielding radiation applications.

Structural, morphological and photoluminescence properties of Eu3+ doped Cd2Sr(PO4)2 nanopowder

Eu3+ doped cadmium strontium phosphate (Cd2Sr(PO4)2CSP) Nanopowder was synthesized by a simple and well known solid-state reaction method (SSR). The prepared nanopowder was characterized by various analytical techniques such as powder X-ray diffraction (P-XRD), scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) studies analysis along with photometric. Based on the results of XRD, the typical crystallite size of the as-prepared nanopowder is found to be 20 nm. The morphological study reveals that the sample has uneven distribution of nano-flakes like structure. The existence of vibrational bands of phosphate ions in the sample were identified by FT-IR spectroscopy. The DRS studies reveal that the sample has wide optical direct bandgap value of 5.4 eV. The Photoluminescence studies showed that the CSP nanopowder sample doped with Eu3+ ions exhibit six distinct emission bands which are ascribed to electronic transitions arose from 5D0 – 7FJ(J=0,1,2,3,4,5) corresponding to wavelengths 538 nm 588 nm, 612 nm, 651 nm, 698 nm and 724 nm respectively. In the present work it was found that the electronic transition from 5D0 → 7F2 at 612 nm (ED) is more intense than the transition from 5D0 → 7F1 at 588 nm (MD) resulting in Eu3+ ions asymmetry nature around the host site. The Photometric parameters like CIE chromatic coordinates, Color Correlated Temperature (CCT), Color Rendering Index(CRI), and Color purity(CP) reveals that the Eu3+ doped CSP nanopowder ions has potential application in the field of solid state lighting.

Structure and properties of strontium phosphate glasses modified with aluminum oxide applied as glass ionomer cement

ABSTRACT. Studied glasses in the system 50P2O5-(49-x)SrO-1AlF3-xAl2O3 (mol%), 0≤x≤4.5, were prepared via the melt-annealing technique. The prepared samples are transparent amorphous network structures. Glasses are still transparent upon the heat treatment at 540 ºC for 4 hours. 27Al nuclear magnetic resonance (NMR) has been applied to determine the structural role of Al2O3. X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Vickers hardness (Hv) measurements have been carried out. XRD spectroscopy is used to investigate the glasses' crystalline features. The crystallinity was enhanced via the heat treatment process. Some of investigated strontium phosphate glasses are recommended to be applied in dental applications.&#x0D; &#x0D; KEY WORDS: NMR, Aluminum oxide, GIC, X-ray diffraction, Strontium phosphate&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2023, 37(3), 653-662. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v37i3.9

Anomalous electrochemical performance of binary silver–strontium phosphate-based electrode material in supercapattery

Mesoporous silver strontium phosphate (SSP) was synthesized through a facile hydrothermal technique and utilized as a positive electrode for supercapattery. Material's morphology, crystallinity, elemental composition, and homogeneity were carried out through SEM, TEM, XRD, EDS, XPS, and EDS mapping. Various electrochemical characterizations were performed in three as well as two electrode assemblies to ensure the ability of the material towards electrochemical charge storage. In fact, three-electrode results explore that the material possesses excellent performance in terms of specific capacity, lower series resistance, and negligible charge transfer resistance. After a conclusive three electrode assembly findings, an asymmetric supercapacitor was assembled by utilizing SSP as a positive electrode and as a counterpart carbon nanotube (CNT) as a negative electrode. This hybrid device reveals excellent electrochemical performance and was able to deliver a specific capacity of 240.0 C/g. Indeed, not only higher capacity was delivered by this device, nevertheless, its performance was remarkable in terms of high energy density and excellent power density. Besides, the rate capability for the supercapattery was estimated from GCD which was ∼77% at the highest current density of 12 A/g. The stability has a significant role in energy storage devices and was analyzed by charging and discharging the device, and the results demonstrate the outstanding specific capacity retention of 86.68% after 5000 cycles. Likewise, the device successfully holds coulombic efficiency of 95.79% by the end of 5000 charge-discharge cycles. Our analysis reveals that this material possesses remarkable energy performance which makes it applicable for future supercapattery devices.

First investigation of the local environment of europium in a strontium phosphate glass using molecular dynamics simulations

Phosphate glasses are characterized by properties distinguished by comparison with those of others such as borates, silicates, and tellurides that can be used in many fields such as optics, electronics, medicine, environmental protection, etc. This study aims to discover the effect of the europium dopant on the structural properties of glasses with 65% P2O5 – (35-x) % SrO – x% Eu3O2 (where x = 0.5, 1, 1.5, 2 mol at. %) using molecular dynamics simulations. The density of simulated glasses was found to increase from 2.784 to 2.860 g/cm3 according to the gradual increase in the europium content. The Eu-O distances and coordination numbers are found to be in the ranges of 2.18–2.21 Å and 6.59–6.79, respectively. The Sr-O coordination numbers were found to decrease from 7.30 to 6.55 with an increase in the europium content in the phosphate glasses. The coordination of the Eu-Eu pair increases from 0.07 to 0.23 with increasing europium concentration in phosphate glasses, but it remains weak, which is a sign of good solubility of europium in the glass matrix, as expected by experiments and the literature. Studies of the cluster statistics in the simulated glasses demonstrate that most europium atoms are found isolated or in a doublet.

Synthesis of 3D porous ceramic scaffolds obtained by the sol-gel method with surface morphology modified by hollow spheres for bone tissue engineering applications

In the present work, we modified the surface morphology of 3D porous ceramic scaffolds by incorporating strontium phosphate (SrP) hollow nano-/microspheres with potential application as delivery system for the local release of therapeutic substances. SrP hollow spheres were synthesized by a template-free hydrothermal method. The influence of the reaction temperature, time and concentration of reactants on precipitates' morphology and size were investigated. To obtain a larger number of open hollow spheres, a new methodology was developed consisting of applying a second hydrothermal treatment to spheres by heating them at 120 °C for 24 h. The X-ray diffraction (XRD) analysis indicated that spheres consisted of a main magnesium-substituted strontium phosphate phase ((Sr0.86Mg0.14)3(PO4)2). The scanning electron microscopy (SEM) micrographs confirmed that spheres had hollow interiors (∼350 nm size) and an average diameter of 850 nm. Spheres had a specific surface area of 30.5 m2/g, a mesoporous shell with an average pore size of 3.8 nm, and a pore volume of 0.14 cm3/g. These characteristics make them promising candidates for drug, cell and protein delivery. For the attachment of spheres to scaffolds’ surface, ceramic structures were immersed in an ethanol solution containing 0.1 g of hollow spheres and kept at 37 °C for 4 h. The scaffolds with incorporated spheres were bioactive after being immersed in simulated body fluid (SBF) for 7 days and spheres were still adhered to their surface after 14 days.