Partial Substitution Research Articles

Mixed Metal Amide-Hydride Solid Solutions for Potential Energy Storage Applications.

Mixed solid solutions have played an important role in improving the kinetics and performance of hydrogen storage materials, as reported for the Li-Mg-N-H, K-Mg-N-H, and Rb-Mg-N-H systems. Besides, the formation of a homogeneous solid solution, mostly due to partial ionic substitution, is known to be an effective approach to improve the ionic conductivity of a material, which is an important property in electrochemical applications. We have reported a series of solid solutions based on mixed amide-hydride materials of the Group 1 elements, e.g., K(NH2)xH1-x, Rb(NH2)xH1-x, and Cs(NH2)xH1-x, via the exchange of NH2-/H- anions with the change of the lattice cell of the solid solution. Extending the research in this direction, we study the M-N-H solid solution in the MNH2-MH systems (M = K, Rb, Cs, and their combinations), i.e., KNH2-RbH, RbNH2-KH, RbNH2-CsH, and CsNH2-RbH via ex situ/in situ XRD, IR, and 1H 2D solid-state NMR. The results obtained confirm the formation of mixed metal amide-hydride solid solutions associated with an exchange between both anionic (NH2- and H-) and cationic species (K+, Rb+, and Cs+). With this study, we aim to create an accessible library of M-N-H solid solutions for further studies as additives for hydrogen storage materials or ionic conductors.

Mössbauer study of iron oxide nanoparticles

AbstractMagnetic nanoparticles have recently attracted attention for biochemical and medical applications like drug delivery and hyperthermia for a variety of reasons with most important being their stability, chemical compatibility, and suitable magnetic properties like moderate specific mass magnetization. Cobalt ferrites are a well‐studied family of materials and the partial substitution of Fe3+ cations by rare earth (RE) ones may be used to tune the magnetic properties. In the present work pure and substituted Co ferrite nanoparticles with nominal stoichiometry CoFe2−xRxO4 (R = Yb, Gd; x = 0.05, 0.1, 0.3) synthesized by the co‐precipitation method are studied with 57Fe Mössbauer spectroscopy to determine the incorporation of RE ions in the spinel lattice. The fitting procedure was based on the standard spinel model using two sextets for the octahedral and the tetrahedral coordinated positions of Fe atoms. All isomer shift values were found within the typical range of high spin ferric ions while quadrupole splitting values strongly suggest that there is a substitution preference; RE ions replace iron ones in octahedral sites. The inversion parameter was found to decrease with RE content (lowest value about 0.534 for CoFe1.90Yb0.10O4) and thermal treatment always results in changing the material toward normal spinel, while pure CoFe2O4 was inverse. Thermal treatment of substituted materials in ambient air at temperature range 1500–1700 K for 12 h increase crystallite size and changes the degree of inversion.

Effect of Partial Substitution of Zr for Ti Solvent on Young's Modulus, Strength, and Biocompatibility in Beta Ti Alloy.

In orthopedics and dentistry, there is an urgent need to obtain low-stiffness implants that suppress the stress shielding caused by the use of metallic implants. In this study, we aimed to fabricate alloys that can reduce the stiffness by increasing the strength while maintaining a low Young's modulus based on the metastable β-Ti alloy. We designed alloys in which Ti was partially replaced by Zr based on the ISO-approved metastable β-Ti alloy Ti-15Mo-5Zr-3Al. All alloys prepared by arc melting and subsequent solution treatment showed a single β-phase solid solution, with no formation of the ω-phase. The alloys exhibited a low Young's modulus equivalent to that of Ti-15Mo-5Zr-3Al and a high strength superior to that of Ti-15Mo-5Zr-3Al and Ti-6Al-4V. This strengthening was presumed to be due to solid-solution strengthening. The biocompatibility of the alloys was as good as or better than that of Ti-6Al-4V. These alloys have potential as metallic materials suitable for biomedical applications.

Characteristic evaluation and environmental validation of self-compacting concrete containing sandstone slurry waste for sustainable usage.

This study aims to understand the impact of concrete ingredients on the environment. To analyze the effect of, three significant indexes have been taken into consideration, which are embodied carbon dioxide index (e-CO2), embodied energy consumption (e-energy), and embodied resource consumption (e-resource) index. The life cycle assessment (LCA) methodology has considered veto comprehending the probable application of sandstone waste in the form of a slurry (Sslurry) and powder (Spowder) for the development of self-compacting concrete (SCC). This study can be proven beneficial to evaluate the potential adverse effects from environmental and energy perspectives. One reference mix and eighteen design mixes of SCC have been designed and developed to perform an experimental program. An environmental impact comparison of the "hybrid" SCC was performed using the OpenLCA life cycle analysis software with Ecoinvent LCIA methods. The outcomes of this experimental program reveal that the partial replacement of pozzolana Portland cement (PPC) with Sslurry can reduce e-CO2 emission along with the e-energy and e-resource parameters. When Spowder was used as the partial substitution of fine aggregate (FA), only the e-resource index decreased, and e-CO2 and e-energy increased. Minimalist impact on the environment has been noticed when SCC is prepared with Sslurry and Spowder. A detailed LCA analysis study justifies the utilization of Sslurry and Spowder in SCC, which exhibits encouraging results concerning strength and quality. Hence, it was observed that Sslurry and Spowder in developing green and sustainable SCC with moderate strength characteristics are beneficial from an environmental impact perspective.

Exploring the physicomechanical properties and biocompatibility traits of CuO Substituted 45S5 bioactive glass through in-vitro analysis

While clinically approved, 45S5 bioactive glass possesses limitations in terms of mechanical and biological properties for broader biomedical applications. To address this, we have synthesized 45S5 bioactive glass with partial substitution of CuO for CaO using the melt-quench technique. We conducted extensive characterization using XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscopy), and UTM (Universal Testing Machine), in-vitro simulated body fluid (SBF) studies, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), antibacterial and hemolysis assays. Our results demonstrate that CuO-substituted glasses exhibit enhanced bioactivity, as evidenced by the formation of a hydroxyapatite layer on their surface after immersion in SBF, confirmed from XRD, FTIR and SEM. Additionally, MTT assay with MG-63 cells reveals improved cell proliferation, particularly with 1.5 mol% of CuO addition. Furthermore, Cu_2 to Cu_4 compositions demonstrate effective inhibition of E. coli (Escherichia coli) colonization. The substitution of CuO also leads to significant improvements in the mechanical properties of these bioactive glasses. The density of 45S5 glass increases from 2.72 to 2.86 g/cc, compressive strength from 53 to 64 MPa and young's modulus from 76.74 to 82.21 GPa after the substitution of copper from 0.0 to 2.5 mol%, respectively. Partial substitution of CuO for CaO in 45S5 bioactive glass significantly enhances its physicomechanical properties and biocompatibility compared to the original 45S5 bioactive glass that can be used as implant materials for various biomedical applications.

Assessment of Lightweight Concrete Properties with Zinc Oxide Nanoparticles: Structural and Morphological Analyses

In recent decades, the use of nanotechnology has increased in many disciplines. Specifically, in the concrete industry, nanotechnology has been used to develop more eco-efficient solutions. There is a rapidly growing interest in using nanoparticles in concrete to tackle environmental impacts. Among the nanoparticles investigated, zinc oxide (ZnO) shows great potential because of its material properties, such as reactivity, non-toxicity, a hard and rigid structure, photocatalytic and photoluminescence properties, and chemical, electrical, and thermal stabilities. This paper focuses on the analysis of the effect of ZnO nanoparticles in lightweight concrete at different concentrations (0.5, 1, 1.5, and 2.0 wt%) using two different methods including (i) addition and (ii) partial substitution for cement. Mechanical properties are determined by compressive strength tests. Chemical and morphological characterization is performed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. This study reveals that an increase in the percentage of ZnO nanoparticles as a substitute for cement directly decreases the compressive strength of lightweight concrete. For ZnO nanoparticles in the addition method, compressive strength is 10% lower than in the control specimens. However, the conclusions indicate constant compressive strength for all ZnO nanoparticle concentrations in the addition method.

Experimental and Numerical Evaluation for Hybrid Reinforced T-Beam with Different Ratios of Recycled Rubberized Concrete

The use of hybrid GFRP and steel bars as main reinforcement increases the flexural capacity of T-section concrete beams and reduces ductility. Adding recycled rubber to the concrete mix would further enhance the ductility of the hybrid system. Evaluation of the concrete's flexural capacity and ductility is the main goal of the current investigation using normal concrete (NC) and rubberized recycled concrete (RRC). Eight T-beams have been experimentally investigated in this research, two beams were reinforced with steel bars and GFRP bars with zero percentage of crumb rubber (C.R). The remaining beams were reinforced with different combinations of GFRP and steel bars with rubberized concrete mixes with partial substitution of sand with recycled crumb rubber by (0%, 7.5%, 10%, and 12.5% replacements by volume) particle size 1.0 to 2.0 mm. The ductility index for the tested hybrid rubberized T-beams (HRTB) BRH1, BRH3a, BRH5, BRH2, BRH4, and BRH6, were higher than BH1 and BH2 by 28.2%, 35.47%, 65.38%, 23.76%, 30.04%, and 56.95% indicating that increasing the percentage of C.R. has a direct effect on increasing the ductility index. The ultimate failure load for the tested HRTB BRH1, BRH3a, and BRH5, decreased by 11.68%, 14.29%, and 17.47% compared to the hybrid T-beam BH1. The energy dissipation decreased for HRTB BRH1, BRH3a, BRH5, BRH2, BRH4 and BRH6 by 7.88%, 12.36%, 17.17%, 8.12%, 12.96%, and 18.28 compared to hybrid T-beams BH1 and BH2. This indicates that the existence of the very weak C.R. was not able to dissipate the energy properly within the concrete matrix. Good agreement was found between the numerical model and experimental results in terms of crack pattern, ultimate loads and deflections.

Partial substitution of soybean meal with microalgae meal (Arthrospira spp. – Spirulina) in grower and finisher diets for broiler chickens: implications on performance parameters, footpad dermatitis occurrence, breast meat quality traits, amino acid digestibility and plasma metabolomics profile

This trial was conducted to evaluate the effects of replacing soybean meal with microalgae meal (MM; Arthrospira spp.) during grower and finisher phases on productive performance, footpad dermatitis (FPD) occurrence, breast meat quality, amino acid digestibility and plasma metabolomics profile of broiler chickens. One thousand day-old Ross 308 male chicks were divided into 5 experimental groups (8 replicates, 25 birds/each): CON, fed a commercial soybean-based diet throughout the trial (0-41 d); F3 and F6, fed the CON diet up to 28 d of age and then a finisher diet (29-41 d) with either 30 or 60 g MM/kg, respectively; and GF3 and GF6, receiving CON diet until 14 d and then diets containing 30 or 60 g MM/kg from 15 to 41 d, respectively. All diets were iso-energetic and with a similar amino acid profile. Growth performances were recorded on a pen basis at the end of each feeding phase and apparent ileal amino acid digestibility was determined at 41 d. Footpad dermatitis occurrence was assessed on all processed birds, while breast and plasma samples were collected for meat quality and metabolomics analysis (proton nuclear magnetic resonance - 1H-NMR). At 41 d, CON group showed higher body weight than F6 and GF6 ones (2,541 vs. 2,412 vs. 2,384 g, respectively; P < 0.05). Overall, GF6 group exhibited the highest feed conversion ratio, while F3 did not present significant differences compared to CON (1.785 vs. 1.810 vs. 1.934 g feed/g gain, respectively for CON, F3 and GF6; P < 0.01). The occurrence and the risk of developing FPD were similar among groups. MM administration increased breast meat yellowness and reduced amino acid digestibility (P < 0.001). The 1H-NMR analysis revealed variations in the levels of some circulating metabolites, including histidine, arginine and creatine, which play important metabolic roles. Overall, these findings can contribute to expand the knowledge about the use of Arthrospira spp. as protein source in broiler diets.

Bio-stimulants as alternatives to mineral fertilizers: influence on chia (Salvia hispanica L.) growth, yield, and fatty acid composition

One of the main components of sustainable agricultural strategies in crop production is substitution of chemical fertilizers with alternatives. This study aimed to examine the effects of partial replacement of mineral fertilizers with bio-stimulants (yeast and/or moringa leaves extract). Field experiment was conducted during two successive seasons 2018/2019 and 2019/2020. The fertilization treatments were distributed in a factorial design. Treatments included 75%, 50% or 0% NPK combined with yeast, moringa extract, or their combination in comparison with control treatment (100% NPK). The partial substitution of mineral fertilizers with yeast and/or moringa extract had significant impacts on growth, yield and quality components. Decreasing NPK level significant decreased growth and yield components of chia plants, except for 75% NPK combined with yeast and/or moringa. In contrast, decreasing NPK level significantly increased the chemical and quality components of chia. Treating with 75% NPK combined with yeast and/or moringa gave the highest micronutrients and fatty acid content. GC analysis showed definition of nine main components, and the major components were linolenic and linoleic acids. Linolenic acid increased with decreasing NPK, and the highest values obtained with bio-stimulant treatments with zero % NPK. The results of this study recommended that partial substitution of 25% of mineral fertilizers with bio-stimulants (yeast and/or moringa) is the best alternative not only for maintaining the growth and yield component, but also improving the quality of chia plants.

Response of partial substitution of MgO for NaOH as the alkali source in hydrogen peroxide bleaching to properties of triploid poplar chemi-thermomechanical pulp

Given the current scarcity of wood fiber resources, it is imperative to investigate the potential of employing weak alkaline hydrogen peroxide for bleaching high-yield pulp (HYP) to meet the increasing demands for paper and paperboard. This work presents an investigation into the characteristics of triploid poplar chemi-thermomechanical pulp (CTMP) hydrogen peroxide bleaching, including the brightness, bleaching yield, bulk, physical strength, and contents of carbohydrates and lignin. The findings show that partial substitution of MgO for NaOH as an alkali source could improve the yield and bulk of the bleached CTMP. When the substitution ratio of MgO for NaOH reached 75 %, the brightness of 74.62 % ISO for the bleached pulp dropped by only 0.47 percent points but the bulk of 2.21 cm3/g increased by 5.74 % compared to those of the control, respectively. Meanwhile, the yield of the bleached CTMP could reach 93.45 %, 5.07 percent points higher than that of the control. The results would be of benefit to the HYP enterprises concerned.

Influence of Steam Curing Temperature on the Characteristic of Self-Compacting Concrete Incorporating Palm Shell Ash

Self-Compacting Concrete (SCC) is proven as durable concrete and applied to constructions. In this paper, a study was conducted to analyze the influence of variations of steam curing temperature (SCT) and water/binder (w/b) ratio on the characteristics of SCC incorporating 10% Palm Shell Ash (PSA) as a partial substitution for cement mass. The SCT was arranged from 25 C to 80 C. The variation of w/b in the compositions of SCC was 0.325, 0.350, and 0.375. The results showed that using PSA, the variation of SCT and the w/b ratio influenced the workability of the fresh concrete. The PSA, SCT, and the w/b ratio affected the concrete compressive strength and mass density. The increased SCT caused a lighter density and greater compressive strength. However, the decreased compressive strength occurred due to an excessive SCT of 70 C and above. The SCT of 60 C, 10% PSA, and w/b ratio of 0.350 in the mixture produced the greatest compressive strength of 36.27 MPa at 28 days of age, while without SCT, the greatest compressive strength of 36.78 MPa was achieved at the age of 28 days containing 10% PSA and w/b ratio of 0.325. It indicated that the w/b ratio was more influential than the SCT on the increase of the SCC compressive strength.

PbBeB2O5: A High-Performance Ultraviolet Nonlinear-Optical Crystal with Functional [BeB2O8]8- Group.

High-performance nonlinear-optical (NLO) crystals need to simultaneously meet multiple basic and conflicting performance requirements. Here, by using a partial chemical substitution strategy, the first noncentrosymmetric (NCS) PbBeB2O5 crystal with a BeB2O8 group was synthesized, exhibiting a two-dimensional [BeB2O5]∞ layer constructed by interconnecting BeB2O8 groups and bridged PbO4 with an active lone pair. The crystal shows a promising UV NLO functional feature, including a strong SHG effect of 3.5 × KDP (KH2PO4), large birefringence realizing phase matchability in the whole transparency region from 246 to 2500 nm, a short UV absorption edge of 246 nm, and single-crystal easy growth. Remarkably, theoretical studies reveal that the BeB2O8 group has high nonlinear activity, which could stimulate the discovery of a series of excellent NLO beryllium borates.

Doping-mediated thermal control of phase transition for supersensitive ratiometric luminescence thermometry

Intelligent luminescent materials, characterized by optical switching in response to thermal stimulation, are highly attractive for cutting-edge temperature sensing technologies. However, the exploration of sensitive and reliable thermometric materials remains challenging. Herein, we establish a phase-transition-driven thermometric model that relies on the reversible transition between the monoclinic (β) and tetragonal (α) phase of LiYO2:Dy3+ crystals under controlled thermal stimulations. Accordingly, the ratiometric emissions from hypersensitive electric diploe transitions (4F9/2 → 6H13/2) drastically varied across the phase-transition temperature range, rendering remarkable thermal sensitivity and resolution (Sr-max = 35.24% K−1, δTmin = 0.009 K). We further demonstrate the extended control of phase-transition temperature and thermal hysteresis by a partial substitution approach. These findings highlight an endogenic approach to constructing customized luminescence thermometers via local crystal-field engineering, which raises new possibilities for practical sensing applications.

Transformation of organic to inorganic nitrogen in NH4+-illite-bearing and Ga-Al-REE-rich bituminous coals: Evidence from nitrogen isotopes and functionalities

Nitrogen is one of the most important elements and mainly occurs as organic forms in coal, and in a few cases, in an inorganic form. Organic nitrogen in coal is mainly derived from the proteins of plants and micro-organisms but sources of inorganic nitrogen remain controversial. One hypothesis for the source of inorganic nitrogen is the organic matter of coal, but this lacks strong evidence. In the Daqingshan Coalfield of Inner Mongolia, northern China, an igneous intrusion in the east of the coalfield led to a coal rank increase from the Hailiushu through the Datanhao mines to the Adaohai mine from the west to east, with NH4+-illite being detected in the coals from the Datanhao and Adaohai mines. These coals are highly enriched in Ga, Al, and rare earth elements (REE). This study aims to explore the transformation of organic to inorganic nitrogen in these coals by means of nitrogen isotopes, element distribution in NH4+-illite, and nitrogen functional groups.The analysis of NH4+-illite by Electron Probe Microanalysis (EPMA) indicates partial substitution of nitrogen during the transition from kaolinite to NH4+-illite. Thermal metamorphism has resulted in the organic nitrogen isotope (δ15No) values in coals from the Adaohai Mine being more positive than those in the Datanhao and Hailiushu mines. 15N is more enriched in NH4+-illite than in the associated organic matter. The distribution of nitrogen functional forms showed a decrease in pyrrolic nitrogen (N-5) and an increase in pyridinic nitrogen (N-6) from coals in the Hailiushu to Datanhao and Adaohai mines. Ammonium quaternary nitrogen (N-Q) was detected in the NH4+-illite-bearing samples. This study provides significant evidence for the conversion of organic nitrogen to inorganic nitrogen in coals as a result of thermal metamorphism.

Assessing the oat oil attributes and partial substitution in cookies with special reference to fatty acid profile

Assessing the oat oil attributes and partial substitution in cookies with special reference to fatty acid profile

Effect of partial substitution of complex phosphates with sodium bicarbonate on aggregation, conformation and gel properties of beef-pork-chicken complex myofibrillar proteins.

Complex phosphates (CP) can improve the physicochemical properties and gelation properties of myofibrillar fibrous protein (MP) in mixed meat products, but an excessive intake of phosphates over a long period of time is harmful to health. The present study investigated the effects of partial or complete substitution of CP with sodium bicarbonate (SB) on the physicochemical properties and gel properties of beef-pork-chicken mixed myofibrillar protein (BPC-MP), aiming to evaluate the feasibility of this method in reducing the amount of phosphate in mixed meat products. Under the optimal substitution conditions, the turbidity of BPC-MP was reduced by 37.8%, the net negative potential was increased by 28.9% and the modulus of elasticity (G') was increased. The tertiary structure indexes of protein (including fluorescence intensity, surface hydrophobicity and active thiol content) were significantly changed, whereas the α-helix and β-turn angle contents in the secondary structure of protein were significantly increased. In addition, the water retention ability and strength of gel were also improved, which were increased by 20.7% and 42.6%, respectively. The results of scanning electron microscopy showed that the SB substitution group had a more compact and ordered microstructure. The results showed that partial substitution of CP with SB reduced the amount of phosphate added to BPC-MP and had a positive effect on the physicochemical and gel properties of BPC-MP. © 2024 Society of Chemical Industry.

Microstructure Strain of ZnMn2O4 Spinel by Regulation of Tetrahedral Sites for High‐Performance Aqueous Zinc‐Ion Battery

AbstractManganese oxides are widely used as cathode materials in aqueous zinc‐ion batteries (AZIBs) due to their low cost, multiple oxidation states, and high theoretical specific capacity. However, the further development of Mn‐based oxides is severely hindered by poor structural reversibility and sluggish reaction kinetics. Herein, a microstructure strain strategy is proposed to regulate the microstructure of MnO6 in ZnMn2O4 (ZMO) through partial atomic substitution on tetrahedral sites. The Ni substitution of ZMO (ZNxMO) with enlarged crystal plane spacing, increased Mn─O bond binding energy, and enhanced oxygen vacancy defects exhibits superior structural stability and faster ion transport kinetics. Correspondingly, the ZN0.5MO/NCNTs cathode delivers a favorable high specific capacity of 239.2 mAh g−1 at 0.1 A g−1 with excellent rate performance as well as longer‐term cycle life (over 3000 cycles at 1.0 A g−1). The outstanding performance of ZNxMO is deeply rooted in its Zn2+‐transport friendly in asymmetric MnO6 channel and the structure reversibility during the Zn2+‐intercalation/deintercalation process. This study provides an excellent example of using a microstructure strain strategy to design stable and high‐specific capacity manganese‐based cathode materials for Zn storage.

Physiological Response of European Sea Bass (Dicentrarchus labrax) Juveniles to an Acute Stress Challenge: The Impact of Partial and Total Dietary Fishmeal Replacement by an Insect Meal

This study aimed to explore the effect of FM substitution by defatted Tenebrio molitor larvae meal (dTM) on the response of European seabass to an acute stress challenge. An FM-based diet was used as a control and two other isoproteic/isoenergetic diets were formulated to replace 50 and 100% of FM by dTM. Each diet was tested in quadruplicate groups of 15 fish (69 ± 5 g) fed until visual satiety for 16 weeks. After the feeding trial, fish were subjected to 1 min air exposure followed by 1 h of recovery before sampling. The haematological profile, plasma metabolites, and humoral immunity biomarkers, as well as hepatic oxidative stress and antioxidant capacity, were analysed. A clear response to acute stress was observed by a significant increase in haemoglobin, haematocrit, red blood cells, and almost all evaluated plasma metabolites and humoral parameters, regardless of dietary treatment. The obtained results demonstrated that partial substitution of FM by IM did not affect the stress response of seabass. However, total FM replacement increased the hepatic activity of total peroxidase and superoxide dismutase in fish fed TM100.

Effect of Ni-Doping on Seebeck Coefficient of LaCoO&lt;sub&gt;3&lt;/sub&gt; System

The aim of this study is discussing the results achieved on undoped and Ni-doped bulk LaCoO3 samples synthesized by solid-state reaction. The crystal structures of the samples were analyzed by x – ray diffraction (XRD) and Rietveld refinement of the XRD patterns was used to test the quality of the samples, the results of this procedure confirmed a single phase of LaCo1-xNixO3 for (x=0 and 0.05) with rhombohedral crystal structure (space group :). The main interest in this class of materials is the possibility of improving the values of Seebeck coefficient and electrical resistivity through chemical doping. The Seebeck coefficient and electrical resistivity were investigated from room temperature (RT) to 450 K, near RT the LaCoO3 system showed a large negative Seebeck coefficient, but it changed to positive value with increasing temperature while the LaCo0.95Ni0.05O3 composition showed a positive Seebeck coefficient throughout all the temperature range. Hence, within this study the Ni substitution led to decrease the electrical resistivity of the samples to one order of magnitude as a result of the partial substitution of Co3+ in LaCoO3 by Ni2+. LaCoO3 was chosen for this thermoelectric test because cobalt oxides have extensive applications.

Apatite-related Na+, Cu2+, Zn2+, CO3 2− containing calcium phosphates nanoparticles: synthesis, characterization and antibacterial properties for medical application

The aim of this study was to prepare and characterize the calcium phosphates modified by different amount of Na+, Cu2+, Zn2+ and CO3 2−, and to investigate their activity in model solution (at pH = 7.45 and 37 °C) and antibacterial properties against Streptococcus pyogenes. According to XRD and FTIR spectroscopy data the apatite-related phases with partial substitution РО4 3− → СО3 2− (B-type) have been prepared. Presence of sodium and carbonate ions led to increase of solubility in model solution during the first 48 h, while modification with both Cu2+ and Zn2+ cations (up to 0.6 wt%) significantly improved antimicrobial properties against Streptococcus pyogenes.