Nickel Inclusions Research Articles

Binder-free Ni-doped In/Mn oxalate electrode for next-generation supercapacitors

The worth of electrochemical energy storage systems is significantly influenced by the nature of the electrode material. In this work, metal oxalates have emerged as cost-effective and robust candidates for application in supercapacitors. In this context, a binder-free electrode composed of in-situ Ni-doped In/Mn oxalate was synthesized. The nickel foam served a dual function, acting both as a structural framework and as a source of nickel. X-ray diffraction (XRD) analysis verified the crystalline nature of the in-situ Ni-doped In/Mn oxalate. Morphological assessment using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the presence of a hybrid one-dimensional/two-dimensional morphology within the in-situ Ni-doped In/Mn oxalate. Electrochemical evaluations indicated that the in-situ Ni-doped In/Mn oxalate electrode exhibits characteristics akin to those of a battery, maintaining 88.8 % of its initial capacity. Furthermore, it demonstrated a superior specific capacity, amounting to 1238.3 F g−1 at a current density of 1 A g−1. The inclusion of nickel during the material's synthesis process is posited to significantly augment its overall electrochemical performance and properties.

Photocatalytic degradation of oxamyl pesticide by adsorption using bentonite/titanium dioxide nanocomposite doped with nickel

The insecticide Oxamyl is available in two forms: granulated and liquid. Eliminating spoilage bacteria in food, drinking water, and sewage treatment is one of the crucial uses of titanium dioxide nanoparticles. Bentonite/TiO2 nanocomposite Ni doping composite and synthetic bentonite/TiO2 composite were produced. The produced nanocomposite were identified using X-ray diffraction, Scanning electron microscopy, elemental analysis, TGA and reflection spectroscopy. The inclusion of Nickel significantly boosts the antibacterial and photocatalytic activity of titanium dioxide/bentonite nanocomposite, may be this is the cause of reaction Nickel ions with nanocomposite. The composites showed thermal stability up to 1000 °C. The produced materials were used in the Oxamyl degradation process. A variety of degrading process parameters were examined. Oxamyl was found to photodegrade in a pH-dependent manner, with pH 12 causing the greatest clearance. The fact that the percentage of removal decreased as catalyst concentration increased indicates that a very small amount of catalyst is required for the degradation. When bentonite and TiO2 composite was present, the maximum degradation rate was 89.5% in 120 min, but when Bentonite/TiO2 composite with Ni doping was included, the maximum degradation rate was 99% for a maximum of 120 min. It is noted that first order kinetics principles apply to the photodegradation. The decrease in the energy gap of titanium dioxide nanoparticles in nanocomposite was associated with the rise in the generation of free radicals and active oxygen brought on by the increase in photocatalytic activity.

Integrating 1D/2D nanostructure based on Ni–Co-oxalate for energy storage applications

The performance of an electrochemical energy storage device highly depends on the electrode material. Currently, metal oxalates are evolving as low-cost and stable electrode materials for batteries and supercapacitors. Herein, mixed metal oxalate (NixCo1-xC2O4/NF) based binder-free electrode was fabricated. The nickel foam contributed not only as a substrate but also as a nickel source. The NixCo1-xC2O4/NF confirmed the crystalline phase through X-ray diffraction spectroscopy (XRD). Scanning electron microscopy (SEM) and transmission electron spectroscopy (TEM) confirmed the integrated 1D/2D-like morphology of NixCo1-xC2O4/NF. The electrochemical results reveled the NixCo1-xC2O4/NF electrode exhibit battery behavior with capacity retention of 86.58 % and possessed the highest specific capacity of 470.012 C g−1 at 1 A g-1. Hence, the nickel inclusion during the synthesis has further enhanced the overall properties and performance of the NixCo1-xC2O4/NF electrode.

Facile synthesis of FeNi alloy-supported N-doped Mo2C hollow nanospheres for the oxygen evolution reaction

The rapid depletion of fossil fuels results in significant environmental pollution. Consequently, researching environmentally friendly and cost-effective electrocatalysts with exceptional oxygen evolution reaction (OER) capabilities holds immense importance in enhancing the efficient utilization of resources. In this paper, a straightforward and cost-effective method was employed to produce Fe-Ni alloy-supported N-doped carbon hollow nanospheres (FeNi/Mo2C/NC) using self-assembled molybdenum dopamine spheres (Mo-PDA-HS) as a substrate. The inclusion of iron and nickel addressed the issue of aggregation and collapse in Mo-PDA-HS nanostructures at high temperatures, while adjusting the electronic structure of the composites to achieve efficient OER activity. The composite displayed a low overpotential (η10 mA = 304 mV) and a minimal Tafel slope (41.8 mV/dec-1). This study introduces a simple strategy for constructing structurally robust and non-aggregating Mo2C nanostructures, along with a direct method for designing cost-effective and high-performance catalysts for OER.

Impact of mobility and effective mass on the thermoelectric performance of Ni doped Cu2Se

Cu2Se, a liquid-like thermoelectric material, has shown tremendous promise in recent years due to its strong electrical properties and intrinsic low thermal conductivity, which might be optimized for future applications by engineering the performance of Cu ions. In the present study, the thermoelectric features of hydrothermally grown Cu2Se are modified by tuning the presence of nickel in the crystalline matrix. The approach of modifying electronic band structures has been explored to optimize carrier transports by balancing the competitive relationship between carrier mobility and effective mass in order to discover improvements in thermoelectric materials beyond nanostructures. Its exceptional thermoelectric performance stems from ultrahigh carrier mobility over the whole working temperature range, which is achieved by effectively modifying the transport parameters through Ni doping. The inclusion of nickel in the Cu2Se lattice at either substitutional or interstitial sites has a substantial influence on its thermal and electrical transport properties. A band sharpening caused by the presence of Ni in the lattice of Cu2Se tailored the carrier's effective mass, resulting in increased carrier mobility without compromising the carrier concentration. A simultaneous enhancement in the carrier concentration and carrier mobility is achieved due to the presence of Ni in the interstitial sites. A maximum power factor of 614 µW/mK2 is observed for the sample doped at 1.5 wt% Ni at 573 K. The lattice distortion and point defects caused by Ni substitution generated additional phonon scattering centers, resulting in a substantial decrease in thermal conductivity. The sample doped with 2 wt% Ni shows a maximum ZT value of 0.535 at 573 K, which is around 3 times higher than that of pristine Cu2Se. These findings show that nickel is a novel efficient dopant that may significantly increase the thermoelectric performance of Cu2Se via defect and band engineering.

Low cost & quasi solid state Na2Mn0.5Ni0.5Fe(CN)6//NaxFe2O3 hybrid Na-ion batteries for solar energy storage

Lowering the band gap is achieved by inclusion of nickel in Na2MnFe(CN)6 and sodium in Fe2O3, which improves the overall electrochemical performances of the respective positive and negative electrodes in an aqueous Na-ion battery.

Разработка технологии комплексной переработки шлаков Златоустовского металлургического завода

Introduction. Currently, many metallurgical companies in Russia are experiencing difficulties with the supply of raw materials. One of the solutions to this problem is the involvement in the reuse of secondary resources that are formed in metallurgical processing. So there are more than 15 million tons of them on the territory of Zlatoust steel Mill. The development of metallurgical slag processing technology will partially solve the problem of the company’s own raw material base. Methodology. To develop an effective technology for complex processing of metallurgical slags of Zlatoust steel Mill four samples were taken from various sections of slag dumps. Research results and discussion. The work studied the chemical and mineralogical composition of samples, conducted studies on the enrichment of slags. To study the enrichment of metallurgical slags by the magnetic enrichment method, studies have been carried out, including separation of material with a size of -100 +40 mm on a drum separator and material with a size of -40+0 mm on a separator in a suspended state. The results show that products made of a material with a size of -100+40 mm meet the requirements for direct use in blast furnace production. and products obtained from a size class of -40+0 mm meet the requirements of agglomeration production. The chemical analysis of the obtained products after magnetic separation in a suspended state indicates significant nickel content in the magnetic separation tails of the sample with a size of -40+0 mm. The study of the microstructure of the sample showed that the size of nickel inclusions is on average 1 mm. In this work studies have been carried out on the grinding of tails to a size of less than 1 mm and enrichment on gravity apparatuses. Studies comparing the results of metallurgical slag enrichment on a concentration table and a centrifugal concentrator have shown significantly higher efficiency of slag separation on a centrifugal concentrator. Conclusions. The obtained results on the enrichment of metallurgical slags ofZlatoust steel Mill allows us to recommend a comprehensive processing technology. As a result of enrichment the following products are obtained: magnetic product 1 with a mass fraction of iron 88.4% when extracting 35.2%. magnetic product 2 with a mass fraction of iron 42.7% when extracting 12.4% and nickel-containing concentrate with a mass fraction of nickel 4.85% when extracting 67.9%.

Heterogeneous Electro-Fenton-like Designs for the Disposal of 2-Phenylphenol from Water

The hunt for efficient and environmentally friendly degradation processes has positioned the heterogeneous advanced oxidation processes as an alternative more interesting and economical rather than homogenous processes. Hence, the current study lies in investigating the efficiency of different heterogeneous catalysts using transition metals in order to prevent the generation of iron sludge and to extend the catalogue of possible catalysts to be used in advanced oxidation processes. In this study, nickel and zinc were tested and the ability for radical-generation degradation capacity of both ions as homogeneous was evaluated in the electro-Fenton-like degradation of 2-phenylphenol. In both cases, the degradation profiles followed a first-order kinetic model with the highest degradation rate for nickel (1 mM) with 2-phenylphenol removal level of 90.12% and a total organic reduction near 70% in 2 h. To synthesise the heterogeneous nickel catalyst, this transition metal was fixed on perlite by hydrothermal treatment and in a biochar or carbon nanofibers by adsorption. From the removal results using the three synthesized catalysts, it is concluded that the best catalysts were obtained by inclusion of nickel on biochar or nanofibers achieving in both with removal around 80% before 1 h. Thus, to synthetize a nickel electrocatalyst, nickel doped nanofibers were included on carbon felt. To do this, the amount of carbon black, nickel nanofibers and polytetrafluoroethylene to add on the carbon felt was optimized by Taguchi design. The obtained results revealed that under the optimised conditions, a near-complete removal was achieved after 2 h with high stability of the nickel electrocatalyst that open the applicability of this heterogeneous system to operate in flow systems.

Bimetallic Oxygen Evolution Electrocatalysts: Relationships of Structure, Activity and Stability

Acidic oxygen evolution reaction (OER) electrocatalysts that have high activity, extended durability, and lower costs are needed to further the development of proton-exchange membrane (PEM) electrolyzers. Within acidic OER catalysts, stability remains a critically important but significantly less studied factor relative to activity. Our work involves investigating relationships between structure, activity, and stability within bimetallic acidic OER electrocatalysts. Bimetallic catalysts that interact iridium or ruthenium with non-noble metals provide an approach to lower the amount of noble metal and increase the OER activity and stability. Non-noble metals have different electronegativities and atomic radii compared to iridium and ruthenium which alters the surface atomic and electronic structure and influences both OER activity and metal dissolution. Our prior work showed that the inclusion of nickel or cobalt within iridium-metal two-dimensional nanoframes resulted in differences in the surface structure that significantly changed the OER activity and electrochemical degradation.1,2 Bimetallic structures can undergo very different degradation processes compared to monometallic structures, as shown by our prior study.1 Our recent work has explored the effects of interacting non-noble metals within ruthenium oxide on the structure, OER activity and stability. Nanostructured bimetallic oxides were synthesized using solution-phase chemistry and through utilizing various temperature/atmosphere treatments. The synthesis and processing conditions significantly affected the resulting material’s structure and properties. The materials’ composition, morphology and structure are probed using energy dispersive X-ray spectroscopy, scanning electron microscopy, nitrogen physisorption, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Rotating disk electrode measurements are used to evaluate the electrochemical oxygen evolution activity and stability of the bimetallic oxides which were compared to baseline OER catalysts. Metal dissolution that occurs during accelerated durability testing is evaluated using inductively coupled mass spectroscopy measurements. Our recent efforts towards understanding the relationships between structure, activity, and stability within nanostructured bimetallic oxides/hydroxides will be presented. References Ying, Y.; Godínez-Salomón, J.F.; Moreno, A.; Lartundo-Rojas, L.; Meyer, B.; Damin, C.A.; Rhodes, C.P. Hydrous Cobalt-Iridium Oxide Two-Dimensional Nanoframes: Insights into Activity and Stability of Bimetallic Acidic Oxygen Evolution Electrocatalysts. Nanoscale Advances 2021, 3, 1976-1996. DOI: 10.1039/D0NA00912A Godínez-Salomón, F.; Albiter, L.; Alia, S.M.; Pivovar, B.S.; Camacho-Forero, L.E.; Balbuena, P.B.; Mendoza-Cruz, R.; Arellano-Jimenez, M.J.; Rhodes, C.P. Self-Supported Hydrous Iridium-Nickel Oxide Two-dimensional Nanoframes for High Activity Oxygen Evolution Electrocatalysts. ACS Catalysis 2018, 8, 10498-10520. DOI: 10.1021/acscatal.8b02171

The properties of oxide-ceramic layers with Cu and Ni inclusions synthesizing by PEO method on top of the gas-spraying coatings on aluminium alloys

Based on thermodynamic calculations, the possible options for forming of oxide-ceramic layers (Al2O3) alloyed with copper and nickel inclusions have been considered. For this purpose, plasma-electrolyte oxidation (PEO) of the directly aluminum alloys surfaces or the gas-thermal coatings sprayed on top of them was used. A sequence of reactions occurring in plasma channels during PEO is proposed. Experimental verification of the obtained oxide-ceramic layers was carried out at the different types of tests. All analyzed oxide-ceramic layers were characterized by high elasticity modulus, hardness and wear resistance. A selective mass transfer effect was detected during friction of the oxide-ceramic layers (alloyed with dispersed copper inclusions) with cast-iron in the boundary lubrication conditions in the motor oil with glycerine addition. The glycerate films of iron and copper were formed during friction process on the surfaces of friction elements. As a result of the friction ratios and the wear resistance of such friction pairs was reduced by an order of magnitude. However, most importantly, the low values in friction coefficient were maintained even at high specific loads.

Electrical discharge metal matrix composite coating on duplex stainless steel and its wear behavior under different environmental conditions

The current study evaluates the effect of inclusion of nickel with a varying concentration that influences the tribological behaviour of the electrical discharge coating over the duplex stainless steel. A flaw free coating was obtained while increasing the nickel weight percentage with an improved hardness of 915HV0.5 to 1100 HV0.5 that trice the time of the substrate. Wear test is carried under a higher temperature of 600 °C in Pin-On-Disc tribometer with the varied environmental condition pin and chamber shows that increase in the concentration of nickel reduces the formation of oxides, surface roughness, and thermal cracks. In addition, electrode copper with carbon from the dielectric deposited within the coating owns strain rate, this significantly accommodates the hard carbides debris as third body wear between the contacts. Analyzing of surface morphology was detailed through 3D optical profilometer together with microstructural transformation, wear mechanism and coating thickness by Scanning Electron Microscope followed through Energy Dispersive Spectroscopy for elemental analysis and hardness through Vickers Microhardness. Moreover, the pyrolysis carbon with nickel accommodates the hard carbides with an inferior frictional coefficient and specific wear rate.

Transformation of Combustion Nanocatalysts inside Solid Rocket Motor under Various Pressures.

In this paper, the dependences of the morphology, particle sizes, and compositions of the condensed combustion products (CCP) of modified double-base propellants (1,3,5-trimethylenetrinitramine (RDX) as oxidizer) on the chamber pressure (<35 MPa) and nickel inclusion have been evaluated under a practical rocket motor operation. It has been shown that higher pressure results in smaller average particle sizes of the CCPs. The CCPs of Ni-containing propellants have more diverse morphologies, including spherical particles, large layered structures, and small flakes coated on large particles depending on the pressure. The specific surface area (SSA) of CCPs is in the range of 2.49 to 3.24 m2 g−1 for propellants without nickel are less dependent on the pressure, whereas it is 1.22 to 3.81 Ni-based propellants. The C, N, O, Al, Cu, Pb, and Si are the major elements presented on the surfaces of the CCP particles of both propellants. The compositions of CCPs from Ni-propellant are much more diverse than another one, but only three or four major phases have been found for both propellants under any pressure. The metallic copper is presented in CCPs for both propellants when the chamber pressure is low. The lead salt as the catalyst has been transformed in to Pb(OH)Cl as the most common products of lead-based catalysts with pressure lower than 15 MPa. When pressure is higher than 5 MPa, the nickel-based CCPs has been found to contain one of the following crystalline phases: Pb2Ni(NO2)6, (NH4)2Ni(SO4)2·6H2O, C2H2NiO4·2H2O, and NiO, depending on the pressure.

Electrografting of mixed organophosphonic monolayers for SI-ATRP of 2-methacryloyloxyethyl phosphorylcholine

Nitinol (NiTi), one of the most important alloys for biomedical applications, is still hampered by its surface nickel inclusions, making it sensitive to pitting corrosion and leading therefore to the release of potentially carcinogenic Ni2+ ions. In this work, we assess the impact of the combination of electrografted mixed self-assembled monolayers (SAMs) on NiTi followed by a polymer coating formed by surface-initiated atom transfer radical polymerization (SI-ATRP). The molecular ratio of 11-(2-bromoisobutyrate)-undecyl-1-phosphonic acid (BUPA) to 11-decylphosphonic acid (C10P) on the electroassisted elaboration of the (BUPA/C10P)-NiTi-SAMs has been optimized. A small amount of BUPA (20%) appears to be the most promising condition, as it provides an efficient corrosion resistance and promotes the SI-ATRP of 2-methacryloyloxyethyl methacrylate (MPC). This confers to the surface hydrophilic properties and corrosion resistance close to those NiTi-SAMs when long polymerization times are used (≥ 6 h).

Geochemistry, mineralogy, and radioactivity of the Abu Furad Area, Central Eastern Desert, Egypt

Abu Furad is in the Central Eastern Desert, Egypt. It comprises metasediments, metavolcanics, metagabbros, syn- to late-orogenic granites, and post-orogenic granites, in addition to numerous dykes and veins of different shapes and composition invading all the older rocks cropping out in the study area. Field, petrographic, mineralogical, and chemical investigations led to the classification of Abu Furad granites as quartz diorite, tonalite, granodiorite, and syenogranites.Major oxide and trace element data revealed that the syn- to late-orogenic granites and post-orogenic granites are peraluminous. Syn- to late-orogenic granites originated from calc-alkaline volcanic arc–related magma; while the post-orogenic granites (syenogranite) are highly fractionated, calc-alkaline granite from a within plate regime. Radiometrically, the studied quartz diorite, tonalite, and granodiorite had lower uranium and thorium contents and higher eU/eTh ratios than the syenogranites. This may indicate that the syn- to late-orogenic rocks originated from sources depleted in these elements. The average eTh/eU ratio of syenogranites was higher than that of average continental crust, suggesting that the syenogranites are relatively depleted in U. The studied altered syenogranites were strongly enriched in U and Th compared to the Earth’s crust. On the other hand, the average of eU in pegmatites is lower than the global average for uraniferous pegmatites. The most recorded accessory minerals in the altered syenogranites were thorite, fergusonite, samarskite, columbite, zircon, monazite, xenotime, apatite, fluorite, sphene, atacamite, and malachite, in addition to chromium and nickel inclusions.

Ni nanocluster composites for enhanced impact resistance of multilayered arc-PVD ceramic coatings

Optimally, hard protective coatings should effectively absorb impact energy to reduce the likelihood of failure events. In this work, an arc-PVD approach was utilised for the deposition of thick ceramic multilayer AlCrTiN/CrN-based coatings containing a distribution of metallic nickel inclusions throughout sequential CrN-based interlayers. The aim of such coatings is to provide resistance to impact loading in intensive application environments, such as drop forging of steel and turbine blades exposed to abrasive particles. The structure and micro-structural development of the ceramic was first investigated using transmission electron microscopy, where discrete Ni inclusions were observed as both larger discs (d ~ 600–800nm, h ~ 200nm) and smaller (d ~ 50nm) nanoclusters. Confirmation of the distribution and nanocluster chemistry was achieved using atom probe tomography. For mono-block coatings, XRD data showed drastically reduced internal stresses as a result of the Ni inclusions, enabling the creation of thicker protective coatings which minimise substrate stress concentration upon loading. Nickel inclusion additionally provides a softening of the containing hard ceramic layer, allowing for tuning of mechanical properties. Supporting this idea, in situ micropillar compression measurements of the multi-layered coating systems showed that Ni clusters hindered crack propagation through the coating during failure, while the fracture strength could be increased by incorporating both Ti and Ni in the softer CrN-based layer. High-load impact testing highlighted the influence of Ni ‘shock absorbers’ in reducing circumferential cracking, which was further confirmed by an industrial die forging test that demonstrated a 15–22% life-time increase compared to a much thicker hard-chrome plated reference. The results of this study demonstrate an exciting way to produce Ni nanocluster integrated hard ceramic multi-layers using arc-PVD in a single processing step. Such tuneable thin-film composite systems show great promise in minimising damage from impact loading, even under severe working conditions such as in hot forging.

Effect of Ni content and Al2O3 particle size on the thermal and mechanical properties of Al2O3/Ni composites prepared by spark plasma sintering

Alumina-nickel composites were prepared by carrying out spark plasma sintering (SPS) of nano-sized and micro-sized Al2O3 particles with 15–45 wt% Ni powders. The powder materials were sintered at a temperature of 1400 °C under a constant uniaxial pressure of 50 MPa. FESEM micrographs of the products showed uniformly dispersed nickel inclusions in both matrices at intergranular positions. Presence of Al2O3 as the major phase along with Ni as the minor phase was confirmed using XRD analysis. Thermal and mechanical properties of the nano- and micro-sized Al2O3/Ni composites were investigated. The thermal conductivity of nano-sized alumina composites was seen to increase with the increase in nickel content, however, an opposite trend was observed for micro-sized alumina-based composites. Moreover, thermal conductivities of all the composites decreased with increase in temperature. The composites also showed high hardness and fracture toughness values of up to 19.6 GPa and 4.71 MPa ∗ m1/2, respectively, and relative density values, between 79 and 99%, that decreased with increasing Ni content. Furthermore, the nano-sized Al2O3/Ni composites showed thermal and mechanical properties superior to those of the micro-sized Al2O3/Ni composites.

Computational approach to study the influence of Mn, Fe, and Ni as additives toward rubber–brass adhesion

The effect of different transition metals (manganese, iron, and nickel) as alternative for cobalt additives toward the performance of rubber adhesion to brass has been investigated by employing modeling approach at density functional theory level. Out of the three different dopants, manganese shows positive results on both sulfide surfaces with notable improvement in adhesion on copper sulfide via carbon–carbon double bond. However, it exhibits lower promotional effect on zinc sulfide than cobalt dopant. Iron, on the other hand, only enhances the adhesion on copper sulfide, while inclusion of nickel displays the lowest promotional effect.

Bioinspired Nacre‐Like Ceramic with Nickel Inclusions Fabricated by Electroless Plating and Spark Plasma Sintering

Hybrid composites of layered brittle‐ductile constituents assembled in a brick‐and‐mortar architecture are promising for applications requiring high strength and toughness. Mostly, polymer mortars have been considered as the ductile layer in brick‐and‐mortar composites. However, low stiffness of polymers does not efficiently transfer the shear between hard ceramic bricks. Theoretical models point to metals as a more efficient mortar layer. However, infiltration of metals into ceramic scaffold is non‐trivial, given the low wetting between metals and ceramics. The authors report on an alternative approach to fabricate brick‐and‐mortar ceramic‐metal composites by using electroless plating of nickel (Ni) on alumina micro‐platelets, in which Ni‐coated micro‐platelets are subsequently aligned by a magnetic field, taking advantage of ferromagnetic properties of Ni. The assembled Ni‐coated ceramic scaffold is then sintered using spark plasma sintering (SPS) to locally create Ni mortar layers between ceramic platelets, as well as to sinter the ceramic micro‐platelets. The authors report on materials and mechanical properties of the fabricated composite. The results show that this approach is promising toward development of bioinspired ceramic‐metal composites.

Tensile strength of Fe–Ni and Mg–Al nanocomposites: Molecular dynamic simulations

In this work, molecular dynamic simulations of the tensile strength of Fe–Ni and Mg–Al nanocomposites in the conditions of high-rate uniaxial tension were carried out. Two different mechanisms of fracture were identified. In the case of nickel inclusion in iron matrix, the fracture begins on the interface between the inclusion and the matrix, a formed void penetrates both into the inclusion and into the matrix; presence of inclusion reduces the tensile strength. In the case of aluminum inclusion in magnesium matrix, fracture takes place into magnesium matrix and does not touch the inclusion; presence of inclusion has practically no effect on the tensile strength. Molecular dynamic simulations were carried out in a wide range of strain rates and temperatures.

Electroassisted Functionalization of Nitinol Surface, a Powerful Strategy for Polymer Coating through Controlled Radical Surface Initiation.

Coating Nitinol (NiTi) surfaces with a polymer layer has become very appealing in the past few years owing to its increased attraction in the biomedical field. Although its intrinsic properties helped ensure its popularity, its extensive implementation is still hampered by its nickel inclusion, making it sensitive to pitting corrosion and therefore leading to the release of carcinogenic Ni2+ ions. Among all recent ways to modify NiTi surfaces, elaboration of self-assembled monolayers is of great interest as their high order confers a reinforcement of the metal surface corrosion resistance and brings new functionalities to the metal for postmodification processes. In this work, we compare the electroassisted and thermally assisted self-assembling of 11-(2-bromoisobutyrate)-undecyl-1-phosphonic acid (BUPA) to the classical immersion process on NiTi surfaces initially submitted to a hydrothermal treatment. Among all tested conditions, the electroassisted grafting of BUPA at room temperature appears to be the most promising alternative, as it allows grafting in very short times (5-10 min), thus preventing its degradation. The thus-formed layer has been proven to be sufficient to enable the surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-(dimethylamino)ethyl methacrylate.