Calcium Nitrate Research Articles

Synthesis and Antimicrobial Analysis of High Surface Area Strontium-Substituted Calcium Phosphate Nanostructures for Bone Regeneration.

Continuous microwave-assisted flow synthesis has been used as a simple, more efficient, and low-cost route to fabricate a range of nanosized (<100 nm) strontium-substituted calcium phosphates. In this study, fine nanopowder was synthesized via a continuous flow synthesis with microwave assistance from the solutions of calcium nitrate tetrahydrate (with strontium nitrate as Sr2+ ion source) and diammonium hydrogen phosphate at pH 10 with a time duration of 5 min. The morphological characterization of the obtained powder has been carried out by employing techniques such as transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis. The chemical structural analysis to evaluate the surface properties was made by using X-ray photoelectron spectroscopy. Zeta potential analysis was performed to evaluate the colloidal stability of the particles. Antimicrobial studies were performed for all the compositions using four bacterial strains and an opportunistic human fungal pathogen Macrophomina phaseolina. It was found that the nanoproduct with high strontium content (15 wt% of strontium) showed pronounced antibacterial potential against M. luteus while it completely arrested the fungal growth after 48 h by all of its concentrations. Thus the synthesis strategy described herein facilitated the rapid production of nanosized Sr-substituted CaPs with excellent biological performance suitable for a bone replacement application.

Biomimetic surface functionalization of Ti metal incorporated with Ca-Zn and evaluation of in-vitro biological properties

This study aims at incorporating Ca2+ and Zn2+ions into the nano-structured titania layer over Ti metal by a simple chemical and thermal treatment approach. The incorporation of these ions was controlled by varying the volumetric ratios of calcium nitrate and zinc nitrate solution on the alkali pre-treated Ti metal followed by heat treatment at 600 °C. The elemental incorporation of Ca predominantly forms calcium titanate and rutile TiO2, while the simultaneous incorporation of Ca-Zn developed anatase TiO2. Subsequently, the optimized Ca-Zn ratio with predominant anatase TiO2 over the surface (Ti-Na-2.5Ca:7.5Zn) of Ti metal was subjected to further detailed evaluation of surface properties and in-vitro characteristics. This dual-element incorporated nanonetwork structure has shown significant improvement in surface roughness and wettability which influence the rate of protein adsorption. Further detailed evaluation displayed the existence of incorporated Zn2+ as ZnO, which supported the Zn/ZnO mediated antibacterial activity against Staphylococcus aureus and Escherichia coli. In-vitro studies also showed the biocompatible efficiency of Ca and Zn ions through their cell adhesion ability, mitochondrial potential, cell viability, and nuclear integrity with minimum effect on single-cell DNA damage towards MG-63 cells. The mRNA expression levels of osteogenic genes such as OSX, RUNX2, OPN, and OCN were analysed using RT-PCR in the MG-63 cells that are cultured over surface-modified Ti metal which further explained the effect of incorporated Ca and Zn ions in regulating their expression. A similar supporting analysis was found during the mineralization process as well, thus this particular surface modification is expected to fasten osteointegration in in-vivo. These promising results suggest our Ca-Zn-incorporated Ti metal as a potential candidate for bone implant applications.

Effects of bacteria-based self-healing nutrients on hydration and rheology of cement pastes

Crack openings in concrete lead to a reduction in its lifespan. Many authors have analysed different techniques that could repair cracks autonomously, being the use of bacteria one of the most promising approaches. Bacteria are often introduced with nutrients in the concrete mixes, and they may alter the cement hydration.In this study, the effects that calcium lactate, calcium nitrate, and yeast extract have on cement pastes during the early hours of hydration were analysed. To accomplish this, calorimetry, in situ X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Vicat and rheology techniques were employed. The results demonstrated that the addition of calcium lactate led to higher values of ettringite, which altered the rheological behaviour of the pastes. Moreover, when added at 4%, calcium lactate also delayed the setting time by inhibiting the reaction of silicates, a similar effect was observed when yeast extract was added. Lastly, the incorporation of nitrate accelerated the setting time.

Relation of fruiting in Seewy date palm cultivar with spraying boric acid and calcium nitrate

Relation of fruiting in Seewy date palm cultivar with spraying boric acid and calcium nitrate

Experimental validation of thermochemical water-sorption materials for thermal energy storage: Building application

Salt hydrates for seasonal heat storage have emerged as an important research topic due to their potential to fulfil the heat demand in the residential and commercial building sector. However, the research undertaken has not yet covered key aspects of their fundamental thermal behaviour understanding e.g. experimentally validation, characterisation methodologies or material screening. The present investigation is aimed to identify promising thermochemical materials in the temperature range of 25–150°C, which are suitable for building applications and waste heat recovery. A list of ten salt hydrates has been screened through an experimental validation, which was developed and optimized for the specific working conditions. The salt hydrates were tested under operational conditions and key properties are assessed (thermal conductivity, specific heat, volume change, etc). Different case studies were used to narrow down to a list of final salts candidates under three theoretical working conditions scenarios for both open and closed systems. The cases of study prioritised high energy density (after one hydration/dehydration cycle), acceptable volume expansion and stability, which led to the final candidates. Magnesium sulphate was selected in the case of high energy density (>2 MJ/m3) and low cost (1 €/MJ), when lowering the energy density to 1 MJ/m3 calcium sulphate and copper sulphate were revealed as promising candidates for open and closed systems. While calcium nitrate was identified as a candidate along with magnesium sulphate when considering closed systems.

Cultivo semi-hidropônico de alface crespa fertirrigada com soluções salinas enriquecidas com nitrato de cálcio

ABSTRACT Lettuce is a leafy vegetable sensitive to salinity, and under saline stress conditions it presents nutritional imbalance, mainly in calcium absorption. Thus, the objective was to evaluate the effect of enriching the nutrient solution with calcium nitrate in solutions prepared with saline water in the lettuce crop. A completely randomized design was used, with five treatments and four replicates. The treatments were represented by five nutrient solutions [S1 - standard nutrient solution (SNP); S2 - SNP + NaCl (3.5 dS m-1); S3 - S2 + Ca (NO3)2 (50% = 6.86 mmol L-1); S4 - S2 + Ca(NO3)2 (100% = 9.15 mmol L-1); S5 - S2 + Ca(NO3)2 (150% = 11.43 mmol L-1)] in lettuce from the curly group, cv. Elba. After preparing the nutrient solutions, the solutions had the following electrical conductivities: 1.8 (S1); 4.8 (S2); 5.4 (S3); 6.0 (S4); 6.6 (S5) dS m-1. Variables of growth, nutrition and postharvest quality of lettuce were evaluated. With the exception of stem diameter, number of total leaves, plant pH and vitamin C content, the other variables were affected by the extra addition of Ca(NO3)2 in the nutrient solutions. The lettuce cv Elba grown in coconut fiber is tolerant to the salinity of 4.8 dS m-1 (S2). In conditions where the use of saline water with 3.5 dS m-1 for the preparation of the nutrient solution is unavoidable, the use of extra doses of Ca(NO3)2 in the lettuce crop is not recommended.

Enhanced immobilization of metal pollutants in sewage sludge ash (SSA)-cement pastes by calcium chloride and nitrate: Experimental and DFT studies

Urbanization, Portland cement production, and urban waste have caused concern about increasing environmental pollution. Sewage sludge ash (SSA) comes from the incinerating plant of sewage sludge, which is a by-product of wastewater treatment. SSA can cause metal pollution if improperly handled. Recycling SSA into cement composite such as concrete (i.e., the most widely used material after water) can obviate landfilling and mitigate CO2 and metal pollutants from cement production and SSA. Chemicals called accelerators, such as CaCl2 and Ca(NO3)2 are used to overcome the relatively slow hydration of SSA cement pastes (CPs). In this study, we found the capability of CaCl2 and Ca(NO3)2 to enhance Mo and Cr immobilization by CPs with SSA (i.e., mixed with Portland and blast furnace types of cement). The mechanistic investigation was performed by employing nitrogen gas adsorption, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. The role of the chemical properties rather than physical characteristics of the hydrates was more significant for the immobilization. CaCl2 and Ca(NO3)2 enhanced more formation of aluminate ferrite tri-sulfate (AFt), increasing the host sites for MoO42- and CrO42-. Density functional theory (DFT) simulations showed the likelihood of SO42- in AFt substituted by MoO42- and CrO42-. The unveiled capabilities and mechanism of CaCl2 and Ca(NO3)2 to enhance the MP immobilization of SSA-CPs disclosed new knowledge for the mitigation strategy of pollution from increasingly generated SSA.

Effects of Calcium Nitrate on Thermal Hysteresis and Corresponding Freezing Characteristics of Silty Sand Mixtures

Effects of Calcium Nitrate on Thermal Hysteresis and Corresponding Freezing Characteristics of Silty Sand Mixtures

Screening and optimisation of in vitro pollen germination medium for sweetpotato (Ipomoea batatas)

BackgroundSweetpotato is an important vegetable and food crop that is bred through sexual crosses and systematic selection. The use of in vitro germination of sweetpotato pollen to test its viability has important theoretical and practical implications for improving the efficiency of sweetpotato crossbreeding by controlling pollination and conducting research on sweetpotato pollen biology.ResultsIn this study, we observed the morphological structure of sweetpotato pollen under a scanning electron microscope (SEM), developed an effective method for the in vitro germination of sweetpotato pollen, and examined the viability of sweetpotato pollen after treating plants at different temperatures before blossoming. Sweetpotato pollen grains are spherical, with an average diameter of 87.07 ± 3.27 μm (excluding spines), with multiple germination pores and reticulate pollen surface sculpture. We applied numerous media to sweetpotato pollen germination in vitro to screen the initial medium and optimised the medium components through single-factor design. The most effective liquid medium for in vitro sweetpotato pollen germination contained 50 g/L Sucrose, 50 g/L Polyethylene glycol 4000 (PEG4000), 100 mg/L Boric acid and 300 mg/L Calcium nitrate, with a pH = 6.0. The optimum growth temperature for pollen development in sweetpotato was from 25 to 30 °C. Neither staining nor in situ germination could accurately determine the viability of sweetpotato pollen.ConclusionsIn vitro germination can be used to effectively determine sweetpotato pollen viability. The best liquid medium for in vitro germination of sweetpotato pollen contained 50 g/L Sucrose, 50 g/L Polyethylene glycol 4000 (PEG4000), 100 mg/L Boric acid and 300 mg/L Calcium nitrate, with the pH adjusted to 6.0. This study provides a reliable medium for the detection of sweetpotato pollen viability, which can provide a theoretical reference for sweetpotato genetics and breeding.

Modulator-Free Green Synthesis of the Calcium-Terephthalate Metal-Organic Framework Derived from Waste Eggshells

Conventionally, the four-component calcium-terephthalate (Ca-BDC) metal–organic framework (MOF), Ca(BDC)(DMF)(H2O), has been synthesized from commercial calcium nitrate (Ca(NO3)2) and calcium carbonate (CaCO3), which in turn are manufactured from naturally-occurring minerals by energy-intensive processes. This study presents a primary investigation on the modulator-free solvothermal synthesis of Ca(BDC)(DMF)(H2O) derived from waste eggshells as green precursors. Ca(BDC)(DMF)(H2O) crystallizes as two possible phases, namely the triclinic (Ca-BDC-tric) and orthorhombic (Ca-BDC-orth) phase. This study presents an in-depth investigation on the influence of reaction temperature and solvent volumes on eggshell-derived Ca(BDC)(DMF)(H2O) product phase. Investigations were conducted at long reaction times to ensure complete reaction of green eggshell precursors. Low water (H2O) and high N,N-dimethylformamide (DMF) volumes were found to inhibit solvothermal synthesis. 7.6 mL H2O was determined to be the minimum H2O volume threshold for successful Ca-BDC-tric synthesis, above which further increasing the H2O volume produced porous Ca-BDC-tric at higher yield, which proved favorable due to reduction of toxic DMF. Ca-BDC-orth and Ca-BDC-tric were obtained at 150 °C and 110 °C respectively, whereas dual-formation of both phases prevailed at 130 °C, thereby informing the rough temperature range at which Ca-BDC-tric morphs into Ca-BDC-orth. Ultimately, this study introduces a green solvothermal method for valorizing eggshell waste into value-added Ca(BDC)(DMF)(H2O) for sustainable eggshell waste management and alleviation of environmental health concerns associated with eggshell disposal.

Long-term effective remediation of black-odorous water via regulating calcium nitrate sustained-release.

Nitrate addition is reported as a cost-effective method for remediating black-odorous water, which is mainly induced by the deficiency of electron acceptor. However, excessive release of nitrate and lack of long-term effectiveness significantly limited the application of direct nitrate dosing technology. Herein, for remediating black-odorous water, we constructed a nitrate sustained-release ecological concrete (ecoN-concrete), in which calcium nitrate (Ca(NO3)2) was dosed into concrete block to regulate the release of nitrate. The results showed that chemical oxygen demand (COD), turbidity, ammonia, phosphate, and sulfate were significantly removed in an ecoN-concrete-contained reactor fed with black-odorous water, and its removal efficiency was largely dependent on Ca(NO3)2 dosage. Meanwhile, the released nitrate was lower than 25% of its total dosage and nitrite was lower than 1.5mg/L during 14days remediation. After three recycles, the removal efficiencies of COD and turbidity by using ecoN-concrete were still more than 85%, indicating an excellent nitrate sustained-release performance of ecoN-concrete, which can be applied for preventing water re-blackening and re-stinking. Further investigation illustrated that the ecoN-concrete (1) decreased the abundance of Desulfovibrio, Desulfomonile, and Desulforhabdus in the phylum of Desulfobacterota to alleviate the odorous gas production and (2) significantly increased the abundance of Bacillus and Thermomonas, which utilized the released-nitrate for consuming organic matters and ammonia. This study provided an artful Ca(NO3)2 dosing strategy and long-term effective method for black-odorous water remediation.

Analysis of corrosion rate, inhibition efficiency, and economic cost of XD3 reinforced concrete related to inhibitor and plasticiser types

The main problem in concrete structure is rebar corrosion, which is caused by the penetration and diffusion of chloride ions into reinforced concrete structures; therefore, it is essential to give the most attention to preventing or limiting the impact of this condition. So, in order to find a practical solution to the problem of corrosion of rebar, the current article focuses on demonstrating the beneficial effects of green and calcium nitrate inhibitors on chloride-induced corrosion. Thus, this paper presented an analytical procedure based on corrosion rates and the economic cost to evaluate the efficacy of such an inhibitor. Ten samples with various concrete mixtures were divided into two groups according to the type of plasticiser and inhibitor have been immersed in an aqueous solution of 3.5 wt% sodium chloride at room temperature for 18 months. The optimal results in which the corrosion rate was significantly reduced were for the two groups of concrete mixtures, first group was (C2), which contains 3 wt% orange peels extract inhibitor mixed with 2.4 wt% Oxydtron as water-resisting admixture, and the second group was (E2) included 3 wt% calcium nitrate inhibitor with 2.4 wt% Oxydtron as water-resisting admixture. These two groups samples have been showed more excellent corrosion resistance against the saline solution after the completed immersion period. The inhibition efficiency analysis showed that there is a direct relationship between the inhibitor concentration and the efficiency of corrosion inhibition. However, the inhibition efficiency in the case of samples containing calcium nitrate inhibitor was higher than their counterparts containing green inhibitor extract. Finally, the economic cost analysis showed that the cost of the green inhibitor extract-containing samples was lower than that of the calcium nitrate inhibitor-containing samples.

Comparison of the effectiveness of mined and by-product South African gypsums and other calcium sources for soil sodicity remediation

Studies evaluating the effectiveness of South African gypsum sources are scarce or outdated because of newly introduced products, such as granulated and liquid gypsums. The efficacy of calcium (Ca) nitrate and micro-fine (MF) calcitic limes in comparison to gypsums has also never been evaluated. The aim of this study was to compare the effectiveness of mined and by-product gypsums and other Ca sources in terms of soil sodicity remediation and saturated hydraulic conductivity (Ksat) improvement. In a controlled laboratory study, 12 mined and by-product gypsums sources, MF calcitic limes and calcium nitrate were surface-applied to a sodic, sandy loam soil to achieve an exchangeable sodium percentage (ESP) of 5%. The soils received 300 mm simulated rainfall, and then soil chemical properties and Ksat were determined. Finer by-product gypsum sources (particularly liquid and flue gas desulphurisation (FGD) gypsums) exhibited faster dissolution rates and superior performance in lowering soil ESP to 4.2–4.7% and pH by 0.5–0.7 units compared to Class A mined gypsums (ESP 9.0–11.1% and 0.2 pH units). Only the liquid, phospho-, FGD gypsums and calcium nitrate significantly increased soil hydraulic conductivity (123–130%) compared to the control. The MF calcitic limes had no effect on the sodic soil properties.

A Novel Model for Transforming Harmful Vehicle Exhaust Emissions into Useful Products

This paper puts forward a vehicle exhaust emission treatment model based on the oxidation of pollutant gases and then reaction with calcium oxide. Our model can remove major pollutants, that is carbon dioxide, carbon monoxide and nitrogen oxide, from car exhaust by converting them into calcium carbonate and calcium nitrate respectively. This model provides a simple, easy and effective measure to control the vehicle exhaust emissions.

Hydrogen Bond-Induced Activation of Photocatalytic and Piezophotocatalytic Properties in Calcium Nitrate Doped Electrospun PVDF Fibers.

In this study, polyvinylidene fluoride (PVDF) fibers doped with hydrated calcium nitrate were prepared using electrospinning. The samples were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), optical spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), Raman, and photoluminescence (PL) spectroscopy. The results are complementary and confirm the presence of chemical hydrogen bonding between the polymer and the dopant. Additionally, there was a significant increase in the proportion of the electroactive polar beta phase from 72 to 86%. It was shown that hydrogen bonds acted as a transport pathway for electron capture by the conjugated salt, leading to more than a three-fold quenching of photoluminescence. Furthermore, the optical bandgap of the composite material narrowed to the range of visible light energies. For the first time, it the addition of the salt reduced the energy of the PVDF exciton by a factor of 17.3, initiating photocatalytic activity. The calcium nitrate-doped PVDF exhibited high photocatalytic activity in the degradation of methylene blue (MB) under both UV and visible light (89 and 44%, respectively). The reaction rate increased by a factor of 2.4 under UV and 3.3 under visible light during piezophotocatalysis. The catalysis experiments proved the efficiency of the membrane design and mechanisms of catalysis are suggested. This study offers insight into the nature of chemical bonds in piezopolymer composites and potential opportunities for their use.

Investigation of the thermal behavior of Ca(NO3)2·4H2O and its application for the regeneration of HNO3 and CaO

Nitric acid pressure leaching has great potential in treating limonitic laterite. A new method is designed to improve the downstream process. The resulting calcium nitrate solution is concentrated/crystallized/pyrolyzed to achieve the regeneration of nitric acid and calcium oxide. Calcium nitrate pyrolysis is the core process to realize the new method, but the dynamic analysis of this process is relatively lacking and the pyrolysis mechanism is controversial. In this paper, TG-DSC, TG-MS and XRD were applied to systematically study the thermodynamics and phase evolution of calcium nitrate tetrahydrate. It is found that pyrolysis of calcium nitrate tetrahydrate can be divided into four stages: removing free water and part of crystal water, removing residual crystal water, stable existence of anhydrous calcium nitrate, and its decomposition after melting. Calcium nitrite and nitrogen are absent in the process of calcium nitrate pyrolysis. Three iso-conversion methods, including Flynn-Wall-Ozawa method, Kissinger-Akahira-Sunose method and Starink method, were applied to determine activation energies of calcium nitrate pyrolysis as 224.4 kJ/mol, 221.8 kJ/mol and 222.2 kJ/mol. The kinetic mechanism model of calcium nitrate pyrolysis determined by Melak method is closer to An model, which is the random nucleation and growth reaction. Calcium nitrate pyrolysis process further expands the industrial application of nitric acid pressure leaching.

Ca-based materials derived from calcined cigarette butts for CO2 capture and thermochemical energy storage

Cigarette butts (CBs) are one of the most common types of litter in the world. Due to the toxic substances they contain, the waste generated poses a harmful risk to the environment, and therefore there is an urgent need for alternative solutions to landfill storage. Thus, this work presents a possible revalorization of this waste material, which implies interesting environmental benefits. CBs were used as sacrificial templates for the preparation of CaO-based materials by impregnation with calcium and magnesium nitrates followed by flaming combustion. These materials presented enhanced porosity for their use in the Calcium Looping process applied either to thermochemical energy storage or CO2 capture applications. The influence of the concentration of Ca and Mg in the impregnating solutions on the multicycle reactivity of the samples was studied. An improved multicycle performance was obtained in terms of conversion for both applications.

Effects of Adding Chitosan on Drug Entrapment Efficiency and Release Duration for Paclitaxel-Loaded Hydroxyapatite-Gelatin Composite Microspheres.

Hydroxyapatite-gelatin microspheres with cone-like pores were synthesized via the wet-chemical method using ammonium dihydrogen phosphate ((NH4)H2PO4) and calcium nitrate (Ca(NO3)2·4H2O) as a source of calcium and phosphate ions with the addition of gelatin, which proved to be more osteoconductive than commercial products, such as fibrin glue and Osteoset® Bone Graft Substitute. Following the method of the previous study for loading paclitaxel (PTX), a drug entrapment efficiency of around 58% was achieved, which is much lower than that of the doxorubicin (DOX)-loaded one. Since PTX is hydrophobic while DOX is hydrophilic, the order of chitosan processing and addition of the solvent were tuned in this study, finally leading to an increase in drug entrapment efficiency of 94%. Additionally, the release duration of PTX exceeded six months. The MTT assay indicated that the effect of drug release on the suppression of cancer cells reached more than 40% after one week, thereby showcasing PTX's capacity to carry out its medicinal functions without being affected by the loading procedures.

Impact of Nutrient Application and Bagging on Development and Quality of Guava (Psidium guajava L.)

Guava is a tropical fruit known for its unique flavor and nutritional benefits. Guava is also recognized for its potential health benefits, including improved digestion and immune system support. The benefits of using calcium nitrate and potassium sulphate spraying in guava includes improved fruit size, enhanced nutrient uptake, increased fruit firmness, and better overall plant health. Calcium nitrate promotes cellular development and strengthens cell walls, while potassium sulphate along with bagging aids in fruit development and improves water uptake. These sprays can result in larger, firmer, and healthier guava fruits, contributing to better market value and consumer satisfaction. Therefore, the present investigation was carried out at the Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj, Uttar Pradesh during the Rainy-2022-23 with a view to determine the effect of different nutrient applications and bagging on guava variety Allahabad Safeda for its growth quality and to work out the economics of various treatments. Under this experiment, overall, 10 treatment was prepared by spraying of different nutrients on plants and bagging of fruits with different polythene bags. From the above experimental finding it may be concluded that the treatment T7 (Ca (NO3)2 @ 2% + Bagging (Red colour Polythene) was found to be best in terms of physical parameters like fruit weight (147.27 g), fruit polar length (8.91 cm), fruit equatorial length (9.46 cm), fruit diameter (8.14 cm), fruit volume (697.02 cm3) among different treatment combinations of guava while T6 (Ca (NO3)2 @ 2% + Bagging (Yellow colour Polythene) and T9 (K2SO4 @ 2% + Bagging (Yellow colour Polythene) was found to be best in terms of quality parameters like TSS (10.12 °Brix), acidity (1.27%), ascorbic acid content (153.17 mg/100 g), reducing sugar (5.24%), total sugar (9.51%).

Improved corrosion protection of a NiTi implant by an electrodeposited HAp-Nb2O5 composite layer

The mechanical and biological characteristics of NiTi alloy provide opportunities in biomedical fields ranging from orthopedics to intravascular stents. However, Ni ion release when the alloy is exposed to corrosive body fluid can lead to long-term health-related concerns. Improved surface engineering via the application of biological layers on the NiTi can contribute to higher corrosion resistance. HAp-based layers were cathodically deposited from an aqueous electrolyte containing calcium nitrate, ammonium dihydrogen phosphate, and concentrations of suspended Nb2O5 particles from 0 to 1 g/L under pulsed current conditions. Surface morphology, topography, and surface chemistry of the electroplated layers were characterized by FESEM, AFM, and FTIR analysis, respectively. The corrosion behavior of the bare and coated samples in Ringer's solution was evaluated by EIS and potentiodynamic polarization; the corroded surfaces were imaged by FESEM. A more compact and smoother surface was formed in the presence of particulate Nb2O5 inclusions. The composite coating showed excellent anti-corrosion properties, increasing the polarization resistance of pure HAp films by >10 times. FESEM imaging of corroded surfaces showed the partial detachment of plate-like HAp crystals from the surface of the coated NiTi in contrast to the pitting of the bare NiTi surface. The surface modification of NiTi by electrodeposited HAp-Nb2O5 composite coatings might play an important role in the future use of NiTi in clinical applications.