@misc{BourasFellahBarilleetal., author = {Bouras, Dikra and Fellah, Mamoun and Barille, Regis and Obrosov, Aleksei and El-Hiti, Gamal A.}, title = {Production of novel Zr-Mg nanoceramics based on kaolinite clay with strong antibacterial activity}, series = {Ceramics International}, volume = {50}, journal = {Ceramics International}, number = {16}, publisher = {Elsevier}, issn = {1873-3956}, doi = {https://doi.org/10.1016/j.ceramint.2024.05.091}, pages = {27949 -- 27960}, abstract = {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.}, language = {en} } @misc{SellamAziziBourasetal., author = {Sellam, Manel and Azizi, Soulef and Bouras, Dikra and Fellah, Mamoun and Obrosov, Aleksei and El-Hiti, Gamal A.}, title = {Degradation of rhodamine B dye under visible and solar light on zinc oxide and nickel-doped zinc oxide thin films}, series = {Optical Materials}, volume = {151 (2024)}, journal = {Optical Materials}, publisher = {Elsevier}, issn = {1873-1252}, doi = {https://doi.org/10.1016/j.optmat.2024.115316}, pages = {1 -- 17}, abstract = {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.}, language = {en} } @misc{BoucharebFellahHeziletal., author = {Bouchareb, Nabila and Fellah, Mamoun and Hezil, Naouel and Hamadi, Fouzia and Montagne, Alex and Obrosov, Aleksei and Yadav, Krishna Kumar and El-Hiti, Gamal A.}, title = {Effect of milling time on structural, physical and photocatalytical properties of Ti-Ni alloy for biomedical applications}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {131 (2024)}, journal = {The International Journal of Advanced Manufacturing Technology}, publisher = {Springer}, issn = {1433-3015}, doi = {https://doi.org/10.1007/s00170-024-13207-5}, pages = {3539 -- 3553}, abstract = {Ti-Ni shape memory alloys (SMA) are used extensively in the field of orthopedics owing to their unique physical and mechanical features, excellent corrosion resistance, and good biocompatibility in the human body environment. This study aims to investigate how milling time affects the characteristics of Ti-Ni alloys which were synthesized with equal atomic percentages by using a high-energy ball milling type (Planetary Micro Mill Pulverisette P7, Fritsch GmbH, Germany) under varying milling periods (2, 6, 12, and 18 h). The duration of the grinding process refines the grain and diminishes the material's porosity, improving the material's physical and structural characteristics as well as its photocatalytic activity. The milled powders of Ti50-Ni50 alloys underwent characterization employing scanning electron microscopy (SEM) associated with an energy dispersive spectrometer (EDS), X-ray diffraction (XRD), and spectrophotometery of visible and ultraviolet light (UV-VIS) to measure the solution absorbance of methylene blue (MB). The results revealed that the milling process influences the particle size and shape of powders, where the proportion of fine particles increased with increasing grinding times from 2 to 18 h due to severe deformation and fracturing. The crystallite size was reduced, and the microstrain increased, attaining values of 29 nm and 0.99\%, respectively. In addition, the pores of samples were decreased to 10 nm at higher milling times. Furthermore, solutions of MB containing powders of Ti50-Ni50 milled at 18 h exhibited good photocatalytic activity with a degradation rate value of 93.23\% after 60 min of irradiation time because of a greater surface area. The improved properties of Ti50-Ni50 alloys make them clinically useful for biomedical implantation in humans. Plus, they are considered to be effective materials for photocatalytic applications.}, language = {en} } @misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Obrosov, Aleksei and Samad, Mohammed Abdul and Montagne, Alex and Abd-Elmonem, Assmaa and Din, Sayed M El and Weiß, Sabine}, title = {Structural, mechanical and tribological performance of a nano structured biomaterial Co-Cr-Mo alloy synthesized via mechanical alloying}, series = {Journal of Materials Research and Technology}, volume = {25}, journal = {Journal of Materials Research and Technology}, issn = {2214-0697}, doi = {10.1016/j.jmrt.2023.06.031}, pages = {2152 -- 2165}, abstract = {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.}, language = {en} } @misc{DahmaniFellahHeziletal., author = {Dahmani, Marwa and Fellah, Mamoun and Hezil, Naouel and Benoudia, Mohamed-Cherif and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Structural and mechanical evaluation of a new Ti-Nb-Mo alloy produced by high-energy ball milling with variable milling time for biomedical applications}, series = {The International Journal of Advanced Manufacturing Technology}, volume = {129}, journal = {The International Journal of Advanced Manufacturing Technology}, number = {11-12}, issn = {1433-3015}, doi = {10.1007/s00170-023-12650-0}, pages = {4971 -- 4991}, abstract = {The main focus of this work is to investigate the impact of varying milling times (2 to 18 h) on the structural and mechanical properties of the developed Ti-Nb-Mo alloy. The morphology, phase composition, microstructure, and mechanical behavior of milled and sintered Ti-25Nb-25Mo alloy samples were characterized systematically using x-ray diffraction, scanning electron microscope, optical microscope, and Vicker microhardness. It was noted that the quantity of the β-Ti phase increased as the milling time increased. After 12 h of milling, the synthesized alloys exhibited a spherical morphology and texture with homogeneous distribution. The milled alloys' structural evolution and morphological changes were found to be dependent on their milling duration. Morphological analysis revealed that the crystallite size and mean pore size decreased when the milling duration increased, reaching minimum values of 51 nm and < 1 μm, after 12 and 18 h respectively. As the milling time increased, the grain size decreased, resulting in an increase in density, microhardness, and elastic modulus. Ti-25Nb-25Mo will presents good anti-wear ability and higher resistance to plastic deformation due to enhanced mechanical characteristics (H/E, and H3/E2). Hence, the developed Ti-25Nb-25Mo alloys with reduced elastic modulus and desirable mechanical properties were found to be a promising option for biomedical applications.}, language = {en} } @misc{FellahHezilBourasetal., author = {Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Montagne, Alex and Obrosov, Aleksei and Jamshed, Wasim and Ibrahim, Rabha W. and Iqbal, Amjad and El Din, Sayed M. and Khalifa, Hamiden Abd El-Wahed}, title = {Investigating the effect of milling time on structural, mechanical and tribological properties of a nanostructured hiped alpha alumina for biomaterial applications}, series = {Arabian Journal of Chemistry}, volume = {16}, journal = {Arabian Journal of Chemistry}, number = {10}, issn = {1878-5379}, doi = {10.1016/j.arabjc.2023.105112}, abstract = {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.}, language = {en} } @misc{BourasFellahBarilleetal., author = {Bouras, Dikra and Fellah, Mamoun and Barille, Regis and Weiß, Sabine and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Improvement of photocatalytic performance and sensitive ultraviolet photodetectors using AC-ZnO/ZC-Ag2O/AZ-CuO multilayers nanocomposite prepared by spin coating method}, series = {Journal of Science: Advanced Materials and Devices}, volume = {9}, journal = {Journal of Science: Advanced Materials and Devices}, number = {1}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2023.100642}, abstract = {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.}, language = {en} } @misc{HamadiFellahHeziletal., author = {Hamadi, Fouzia and Fellah, Mamoun and Hezil, Naouel and Bouras, Dikra and Laouini, Salah Eddine and Montagne, Alex and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei and El-Hiti, Gamal A. and Yadav, Krishna Kumar}, title = {Effect of milling time on structural, physical and tribological behavior of a newly developed Ti-Nb-Zr alloy for biomedical applications}, series = {Advanced Powder Technology}, volume = {35}, journal = {Advanced Powder Technology}, number = {1}, issn = {1568-5527}, doi = {https://doi.org/10.1016/j.apt.2023.104306}, abstract = {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.}, language = {en} } @misc{DahmaniFellahHeziletal., author = {Dahmani, Marwa and Fellah, Mamoun and Hezil, Naouel and Benoudia, Mohamed-Cherif and Obrosov, Aleksei and El-Hiti, Gamal A. and Weiß, Sabine}, title = {Bioactivity and tribological performance of a novel nano-biomaterial beta-type Ti-alloy}, series = {Journal of materials research and technology}, volume = {36}, journal = {Journal of materials research and technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2214-0697}, doi = {https://doi.org/10.1016/j.jmrt.2025.03.180}, pages = {2297 -- 2316}, abstract = {This study investigates the bioactivity; wear performance, and topography of a novel beta-type titanium-based alloy using techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and 2D and 3D analysis. The tribological test was evaluated using a ball-on-disk tribometer in a wet environment. Different loads of 2, 6, and 10 N were applied during the evolution. The data results indicate a significant effect of the milling process on the formation of the hydroxyapatite layer on the surfaces of the Ti-Nb-Mo alloy. Both the wear volume and rate showed a consistent trend of decrease as the milling time increased from 2 to 12 h for all applied loads. The minimum values of wear and volume were reached after 12 h of milling. The improvement in tribological behavior can be attributed to the improved mechanical properties of the alloys. In addition, the significant presence of niobium (Nb) and molybdenum (Mo) plays a critical role in achieving high coefficient of friction values. The primary wear mechanism observed in the Ti-25Nb-25Mo system was adhesive wear in addition to abrasive wear. With its lower Young's modulus and favorable biological and tribological properties, the Ti-25Nb-25Mo alloy represents a promising option for bone tissue applications in orthopedics.}, language = {en} }