TY - GEN A1 - Bouras, Dikra A1 - Fellah, Mamoun A1 - Mecif, Abla A1 - Barillé, Régis A1 - Obrosov, Aleksei A1 - Rasheed, Mohammed T1 - High photocatalytic capacity of porous ceramic-based powder doped with MgO T2 - Journal of the Korean Ceramic Society N2 - To purify water at low cost for our daily life, the effect of ceramic-based (mullite–cristobalite) and (mullite–zircon) powders doped with different amounts of magnesium oxide (MgO) (10 and 20 wt%) was studied. These compounds are made of a local raw material DD3 with addition of zirconia (ZrO2) to create an open porosity. The powders were prepared by the traditional mixing method with the help of an automated crushing. The effect of MgO doping on structural, morphological and photocatalytic properties of the material was studied by various analytical techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared, and UV–visible spectrometry. The results of XRD proved that there was a deformation in the crystal structure of the two types of ceramics after addition, which resulted in a shift of the spectra to the right, while SEM proved the presence of pores with a larger size as the proportion of MgO increases. The chemical composition of the basic components of the ceramic compounds as well as the additive was confirmed with EDS and IR spectra. The final results show that ceramics with added zirconia (DD3Z) and doped with 10% of MgO have a better photocatalytic efficiency than ceramics without zirconia. This important effect could be related to the higher rate of porosity, which provides a more active surface. The 10% MgO content showed a high photoactivity of 77.33% in only 15 min. The maximum hydrolysis rate obtained with Orange II was 92.95% after a period of 45 min with DD3Z/MgO powders. Y1 - 2023 UR - https://link.springer.com/article/10.1007/s43207-022-00254-5 U6 - https://doi.org/10.1007/s43207-022-00254-5 SN - 2234-0491 IS - 60 SP - 155 EP - 168 ER - TY - GEN A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Bouchareb, Nabila A1 - Larios, Alejandro Perez A1 - Obrosov, Aleksei A1 - El-Hiti, Gamal A. A1 - Weiß, Sabine T1 - Investigating the effect of Zr content on electrochemical and tribological properties of newly developed near β-type Ti-alloys (Ti–25Nb-xZr) for biomedical applications T2 - Journal of Science: Advanced Materials and Devices N2 - In order to create alloys with exceptional properties for orthopedic uses, this study focuses on the impact of zirconium (Zr) content on the structural, electrochemical, and tribological qualities of nanostructured Ti–25Nb-xZr [x = 5, 10, 15, 20, 25, and 30 atomic (at.) %] alloys. The structural evolution was investigated using XRD and SEM techniques. The mechanical characteristics of the produced alloys, including Vickers hardness and Young's modulus, were measured. In addition, the corrosion tests were performed using the OCP, EIS, and PD methods in Ringer's solution within the independent pH range at 37 °C. A ball-on-disc tribometer was used to investigate the tribological behavior of the alloys under various loads and wet conditions using the Ringer solution. It has been verified that Zr content (at. %) in the alloys had an impact on their morphologies, structural evolution, and mechanical characteristics. According to the morphological analysis, the particle and crystallite size decreases with increasing Zr content. Young's modulus and Vickers hardness show the same tendency. The EIS data demonstrated that a single passive film formed on the alloy surfaces, and the addition of Zr enhanced the corrosion resistance of the passive films. The polarization curves demonstrate that the alloys had low corrosion current densities and large passive areas without the passive films disintegrating. Likewise, the inclusion of Zr resulted in a reduction in the corrosion and passive current densities values. All of these results suggested that the titanium alloys exhibit a more noble electrochemical activity caused by Zr. From the tribological perspective, it was found that the friction coefficient of the alloys reduced with increasing Zr content. KW - Ti-Nb-Zr alloys KW - Nanobiomaterials KW - Tribological behavior KW - Corrosion KW - Ringer's solution KW - Biomedical applications Y1 - 2024 UR - https://www.sciencedirect.com/science/article/pii/S2468217924000261 U6 - https://doi.org/10.1016/j.jsamd.2024.100695 SN - 2468-2179 ER - TY - GEN A1 - Bouras, Dikra A1 - Fellah, Mamoun A1 - Barille, Regis A1 - Obrosov, Aleksei A1 - Ikbal, Amjad A1 - Avramov, Pavel V. A1 - El-Hiti, Gamal A. T1 - Multiple layers, porous surface, and their role in increasing the efficiency of photocatalytic coating on (DD3, DD3+ZrO2) ceramics and glass T2 - Ceramics International N2 - Magnesium-doped zinc oxide thin films were dip-coated onto porous ceramic and glass substrates under identical conditions (50 layers, same doping ratio). Structural, morphological, and photocatalytic properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), UV–visible spectrophotometry, and confocal microscopy. XRD analysis indicated a shift in peak positions towards higher angles, increased grain size, and lattice distortion on both substrates. Unique flower-shaped crystalline granulates were observed exclusively on the ceramic substrate (DD3Z). The energy gap decreased on the ceramic and increased on the glass substrate. The photocatalytic activity was evaluated using an aqueous orange II solution, showing significantly higher decomposition (80 ± 0.53 % after 6 h) on the ceramic compared to the glass substrate (30 %). The enhanced performance on ceramic substrates, particularly with DD3+ZrO2, was attributed to increased microporosity, surface roughness, and active material incorporation, facilitating greater photocatalytic efficiency. The findings suggest promising applications of these materials for efficient and cost-effective photocatalysis, with potential for reuse after thermal treatment at 500 °C. KW - Magnesium oxide KW - Magnesium-doped zinc oxide/DD3+zirconium oxide KW - Magnesium-doped zinc oxide/glass KW - Degradation capacity KW - Nanotechnology KW - Nanocomposites Y1 - 2024 U6 - https://doi.org/https://doi.org/10.1016/j.ceramint.2024.08.239 SN - 1873-3956 VL - 50 IS - 21, C SP - 43854 EP - 43873 ER - TY - GEN A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Habeeb, Majeed Ali A1 - Hamadi, Fouzia A1 - Bouchareb, Nabila A1 - Laouini, Salah Eddine A1 - Larios, Alejandro Perez A1 - Obrosov, Aleksei A1 - El-Hiti, Gamal A. T1 - Microstructural and photocatalytic properties of nanostructured near-β Ti-Nb-Zr alloy for total hip prosthesis use T2 - Kuwait Journal of Science N2 - With its unique corrosion resistance, light weight, mechanical strength, and biocompatibility, TNZ is a versatile metal alloy that is used in the aerospace and medical industries. The current study aims to investigate the effect of milling time (2, 12, 24, and 36 h) on the nanostructured ternary alloy Ti-25Nb-25Zr (TNZ) prepared by high energy ball milling, a process involving the use of a high-energy ball mill to mix and grind the alloy powders, on its structural, physical, and photocatalytic characterizations. The alloys' characteristics, such as morphology, structural properties, relative density/porosity, surface roughness, hardness, and Young's modulus, were evaluated using SEM, XRD, surface profilometer, and microdurometer, respectively. The photocatalytic characterization was conducted by measuring their absorbance as a function of time using a spectrophotometer of visible and ultraviolet light in the wavelength range of 250–650 nm. Results showed that the crystallite and mean pore size reduced with increasing milling time, with the smallest values of 25 nm and 34 μm, respectively, after 36 h. This indicates that longer milling times result in a more compact and uniform structure, which could enhance the mechanical properties of the alloy. Structural characterization shows that the amount of the β-Ti phase increased with increasing milling time, resulting in the spherical morphology and texturing of the synthesized alloys. The milled alloys' structural evolution and morphological changes were sensitive to their milling times. Also, the relative density, Young's modulus, and hardness increased, reaching values of 89 %, 105 GPa, and 352 HV, respectively, due to grain size decreasing with increasing milling time. This suggests that longer milling times lead to a denser and harder alloy, which could be beneficial for its use in total hip prostheses. The photocatalytical characterization demonstrated that the degradation of orange II (OII) increased with increasing milling time. The Ti-25Nb-25Zr catalyst gave the best degree of degradation, which meant that the decolorization process could be operated rapidly and at a relatively low cost without UV irradiation. KW - Ti-25Nb-25Zr alloy KW - Biomaterial alloys KW - Total hip replacement KW - Photocatalytic KW - Biocompatibility KW - Artificial bone KW - Orthopedic implants Y1 - 2024 U6 - https://doi.org/https://doi.org/10.1016/j.kjs.2024.100276 SN - 2307-4116 VL - 51 IS - 4 SP - 1 EP - 12 PB - Elsevier ER - TY - GEN A1 - Bouras, Dikra A1 - Fellah, Mamoun A1 - Barille, Regis A1 - Obrosov, Aleksei A1 - El-Hiti, Gamal A. T1 - Production of novel Zr–Mg nanoceramics based on kaolinite clay with strong antibacterial activity T2 - Ceramics International N2 - Gram-negative bacteria Pseudomonas putida, Gram-positive Bacillus subtilis, and Staphylococcus aureus were utilized as test samples to evaluate the antibacterial characteristics of DD3-clay/MgO and DD3+38 wt% ZrO2-clay/MgO nanoparticles. The ceramic powders prepared by a thermal autoclave method are characterized before and after Mg addition by SEM, EDX, XRD, IR, UV–visible, and TEM in order to investigate microstructure, phase, and surface morphology. The results showed that after adding Mg, it led to the deformation of the crystal lattices of (mullite, zirconium silicate, and zirconium oxide) together with a decrease in particle size (75–103 nm) and a complete change in its shape from nanotube to nanospherical, as observed by SEM and TEM analyses. It also confirmed by UV–visible spectroscopy that the addition of Mg increases the absorbance accompanying a decrease in the energy gap of 1.91, 1.74, 1.73, and 1.43 eV corresponding to DD3, DD3Z, DD3/30 wt% Mg and DD3Z/30 wt% Mg respectively. The antibacterial mechanism is related to the size of the particles, the solvent used for powder dissolution, the nanoparticle's size when they come into touch with bacteria, and the generation of reactive oxygen species (ROS: ˙O2−, ˙OH, and H2O2). It was observed that the anti-bacterial activity is enhanced with 10 wt% and 30 wt% of Mg added to a modified ceramic powder. Also, more O2− is formed on the surface of the prepared powder, which penetrates the bacterial cell and destroys it. The nanocomposite particles showed remarkable antibacterial activity when they were dissolved in DMSO compared to methanol and chloroform as organic solvents. The aim is to enrich knowledge on the antibacterial activities of metal nanoparticles (ZrSiO4 and MgO) on three bacterial strains with different Grams due to their extensive involvement in the phenomena of contamination and infection encountered in the medical field. The synthesized nanoparticles have good antimicrobial activity against all strains tested. A maximum inhibition zone of 35 ± 0.2 mm was obtained with S. aureus, a zone of 23 ± 0.46 mm with P. putida and a zone of 27 ± 0.46 nm with B. subtilis for DD3/30 wt% Mg and an inhibition zone of 38 ± 0.93 mm, 26 ± 0.24 nm and 17 ± 0.33 nm was obtained with same strains for DD3Z/30 wt% Mg, respectively. KW - DD3 + 38 wt% ZrO2/Mg KW - Nanoparticles KW - Synthesis KW - Antibacterial activity KW - Transmission electron microscope KW - Nanomaterial Y1 - 2024 U6 - https://doi.org/https://doi.org/10.1016/j.ceramint.2024.05.091 SN - 1873-3956 VL - 50 IS - 16 SP - 27949 EP - 27960 PB - Elsevier ER - TY - GEN A1 - Sellam, Manel A1 - Azizi, Soulef A1 - Bouras, Dikra A1 - Fellah, Mamoun A1 - Obrosov, Aleksei A1 - El-Hiti, Gamal A. T1 - Degradation of rhodamine B dye under visible and solar light on zinc oxide and nickel-doped zinc oxide thin films T2 - Optical Materials N2 - The kinetic investigation of rhodamine B dye's photocatalytic degradation, chosen as a model pollutant, was conducted at room temperature using Zinc oxide (ZnO) and nickel-doped zinc oxide (Zn0.97Ni0.03O) photocatalysts synthesized through the spray pyrolysis method. XRD analysis confirmed the formation of hexagonal ZnO and Zn0.97Ni0.03O films, with crystallite sizes ranging from 19 to 29 nm and varying in mean average grain size from 72 nm to 88 nm. The surface morphology of the Ni-doped ZnO films was influenced by nickel doping, observed through SEM and TEM micrographs, revealing a dense structure of spherical-shaped crystals. Light transmission and optical band gap energy of the films ranged between specified values, ranging from 3.27 to 3.24 eV. The degradation process was assessed under various conditions, including different light sources (UV lamp and solar irradiation), pH levels, and substrate concentrations. Degradation followed a pseudo-first-order kinetic model, with rate constants (k) and half-life times (t1/2) calculated accordingly. The degradation efficiency of undoped ZnO and ZnO doped with nickel decreased with increasing concentration under UV irradiation from (0.1–0.5 M) under UV irradiation decreased from (34.29–45.02) (49.61–56.61), while under visible light are (40–45.07 %) (58.46–60.24 %), removal rates ranged within specific percentages. The porous Zn0.97Ni0.03O synthesized at 0.5 M exhibited the highest photocatalytic efficiency due to its enhanced crystallinity, resulting in degradation rates of 9.22 and 11.22 × 10−3 min−1 and half-life times of 75.18 and 61.77 min at 90 min specified for both UV and solar light irradiations, respectively. Acidification of the reaction medium accelerated the photocatalytic degradation kinetics, while alkalization slowed it down. These findings mark a significant advancement in the utilization of oxide semiconductors for water pollutant degradation under natural sunlight. KW - Zn0.97Ni0.01O KW - Rhodamine B KW - Heterogeneous photocatalysis KW - Solar irradiation Y1 - 2024 U6 - https://doi.org/https://doi.org/10.1016/j.optmat.2024.115316 SN - 1873-1252 VL - 151 (2024) SP - 1 EP - 17 PB - Elsevier ER - TY - GEN A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Obrosov, Aleksei A1 - Samad, Mohammed Abdul A1 - Montagne, Alex A1 - Abd-Elmonem, Assmaa A1 - Din, Sayed M El A1 - Weiß, Sabine T1 - Structural, mechanical and tribological performance of a nano structured biomaterial Co–Cr–Mo alloy synthesized via mechanical alloying T2 - Journal of Materials Research and Technology N2 - The influence of milling time on the tribological behavior of a Co–Cr–Mo alloy designed for biomedical applications, synthesized via mechanical alloying is investigated. Elemental Co, Cr and Mo powders are milled using different milling times (2, 6, 12 and 18 h) in a high-energy ball mill. The resulting powders were subjected to cold uniaxial and hot isostatic pressing respectively, followed by sintering to obtain cylindrical samples, which were evaluated for their structural, mechanical and the wear behavior. Results showed that the grain and crystallite sizes of the powders decreased with increasing milling time, reaching low values of <10 μm and 32 μm respectively, at higher milling times. Furthermore, the wear rates and the coefficients of friction were lower, at higher milling times due to high densities (96%), and higher elasto-plastic resistance, as presented by the H/E and H3/E2 values of 0.026 and 0.0021 GPa, respectively. Increased milling time enables the refinement of grains and reduction in porosity in the Co–Cr–Mo alloy, which in turn increases the alloy's elasto-plastic resistance and enhances its wear resistance. KW - Tribology KW - Wear resistance KW - Friction KW - Powder metallurgy KW - Co–Cr–Mo alloy Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S2238785423012796 U6 - https://doi.org/10.1016/j.jmrt.2023.06.031 SN - 2214-0697 VL - 25 SP - 2152 EP - 2165 ER - TY - GEN A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Montagne, Alex A1 - Obrosov, Aleksei A1 - Jamshed, Wasim A1 - Ibrahim, Rabha W. A1 - Iqbal, Amjad A1 - El Din, Sayed M. A1 - Khalifa, Hamiden Abd El-Wahed T1 - Investigating the effect of milling time on structural, mechanical and tribological properties of a nanostructured hiped alpha alumina for biomaterial applications T2 - Arabian Journal of Chemistry N2 - In this work was prepared α-Al2O3 alloys from laboratory aluminum oxide powder that was milled for different periods of time and sintered at a temperature of 1450 °C. The difference between the prepared samples was studied using several experimental measurement techniques, including X-ray diffraction, scanning electron microscopy and measurement of physical and mechanical properties. Moreover, the effect of milling time on the formation and sintering of alpha-alumina, by milling the mixture at different times using high energy crushing technique was studied. An influence of milling time on density, open spaces and microstructure of the samples was analyzed. The obtained results showed that longer milling duration led to alloys with higher hardness (H) and modulus of elasticity (E). This improvement is due to lower porosity and corresponding higher density at high temperatures. A noticeable decrease in the size of the particles with the increase of the milling time led to an increase in the lattice parameter accompanied by a decrease in defects and ionic voids. The percentage of pores reached 0.04 % within 24 h of grinding after it was approximately 0.20 %, while the density reached 96 % after the same highest grinding time. Tests showed that the value of friction coefficient decreases, while it increases with the increase in the applied pressure force and this was confirmed by SEM images of the samples. the main factor to reduce friction is the increase in grinding time, regardless of the value of the applied load. The results showed that the Al2O3 alloy applied to it with a load of 2 N and milled for 24 h had a minimum value of 1.94 µm3 wear volumes and a wear rate of 1.33 (µm3∙N−1∙µm−1). The sample milled for 24 h showed the best result, characterized by the lowest wear size, specific wear rate and the highest hardness with extraordinary density of 96 %, which is important in the field of biomaterials applications. KW - α-Al2O3 KW - Milling time KW - Nanomaterials KW - Particle size KW - Hardness KW - Biomaterials KW - Biomedical applications Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S1878535223005749 U6 - https://doi.org/10.1016/j.arabjc.2023.105112 SN - 1878-5379 VL - 16 IS - 10 ER - TY - GEN A1 - Bouras, Dikra A1 - Fellah, Mamoun A1 - Barille, Regis A1 - Weiß, Sabine A1 - Samad, Mohammed Abdul A1 - Alburaikan, Alhanouf A1 - Khalifa, Hamiden Abd El-Wahed A1 - Obrosov, Aleksei T1 - Improvement of photocatalytic performance and sensitive ultraviolet photodetectors using AC-ZnO/ZC-Ag2O/AZ-CuO multilayers nanocomposite prepared by spin coating method T2 - Journal of Science: Advanced Materials and Devices N2 - Morphological and optical properties of a multilayer film (CAZO/CZAO/ZACO) prepared by spin-coating method and deposited on a glass substrate were evaluated. The study was initially carried out for each layer, individually and then as a multilayer subsequently. Structural properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectra (IR) and X-ray photoelectron Spectroscopy (XPS) showed the presence of three phases of zinc, copper and silver oxides at different levels. The CZAO sample observed with scanning electron microscope (SEM) showed an excellent porous surface with a large deformation in the multilayer configuration. Doping with zinc and copper in the silver crystal lattice improved the crystal structure and reduced the optical energy gap, thus increasing the optical absorbance and refractive index. The dielectric constants and showed an increase in the optical polarization values for lower photonic energies. The maximum degradation rate for photocatalysts of methylene blue was 89 % for a 5-h exposure period with CAZO/CZAO/ZACO while it reached 71 % for the CZAO sample during the same time period. The sensitivity of samples to light proved that the presence of ultraviolet radiation increases the number of holes trapped by oxygen ions and causes more free electrons and contribute to a better production of photocurrent than in darkness. KW - Multilayer CAZO/CZAO/ZACO KW - Spin-coating KW - Energy gap KW - Photocatalysis KW - Photodetector KW - Nanostructures KW - Nanocomposites Y1 - 2024 U6 - https://doi.org/10.1016/j.jsamd.2023.100642 SN - 2468-2179 VL - 9 IS - 1 ER - TY - GEN A1 - Hamadi, Fouzia A1 - Fellah, Mamoun A1 - Hezil, Naouel A1 - Bouras, Dikra A1 - Laouini, Salah Eddine A1 - Montagne, Alex A1 - Khalifa, Hamiden Abd El-Wahed A1 - Obrosov, Aleksei A1 - El-Hiti, Gamal A. A1 - Yadav, Krishna Kumar T1 - Effect of milling time on structural, physical and tribological behavior of a newly developed Ti-Nb-Zr alloy for biomedical applications T2 - Advanced Powder Technology N2 - Titanium (Ti)-based alloys with only a β-phase have attracted academic and industrial interest for orthopedic application, due to their close properties to those of tissues. The current study aims to investigate the effect of milling time (2 h, 6 h, 12 h and 18 h) on the nanostructured ternary alloy Ti-25Nb-25Zr prepared by high energy milling, on its structural, physical and tribological behaviors. The alloys’ characteristics such as relative density/porosity, surface roughness, were evaluated using XRD, SEM, surface profilometry, and microdurometer, respectively. The tribological characterization was done using an oscillating tribometer under wet conditions, simulating the human body environment. Results showed that the crystallite and mean pore size reduced with increasing milling time, with the smallest values of 26 nm and 40 µm, respectively after 18 h. Structural characterization shows that the amount of the β-Ti phase increased with increasing milling time, resulting in spherical morphology and texturing of the synthesized alloys. The milled alloys' structural evolution and morphological changes were sensitive to their milling times. Also, the relative density, Young’s modulus and hardness, increased due to grain size decreased with increasing milling time. Tribological results showed that the effect of milling has a significant effect on both nanomaterial formation and friction-wear behavior of the alloys. The results showed that, friction coefficient and wear rate significantly decreased due to the increased formation of protective films such as TiO2, Nb2O5 and ZrO2 phases. The wear mechanism of the Ti-25Zr-25Nb system was dominated by abrasion wear accompanied by adhesion wear. KW - Ti-25Nb-25Zr alloy KW - Biomaterials alloys KW - Total hip prosthesis KW - Milling time KW - Tribology KW - Wear KW - Nanomaterial KW - Nanocomposites Y1 - 2024 UR - https://www.sciencedirect.com/science/article/pii/S0921883123003710 U6 - https://doi.org/https://doi.org/10.1016/j.apt.2023.104306 SN - 1568-5527 VL - 35 IS - 1 ER -