@article{RimHezilFellahetal.2025, author = {Rim, Imen and Hezil, Naouel and Fellah, Mamoun and Saoudi, Adel and Aleksei, Obrosov and El-Hiti, Gamal A.}, title = {Enhancing kaolin performance through organic molecule modification and assessing its efficiency for lead and copper adsorption}, series = {Environmental Technology \& Innovation}, volume = {36}, journal = {Environmental Technology \& Innovation}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2352-1864}, doi = {10.1016/j.eti.2024.103904}, year = {2025}, abstract = {The research aimed to enhance the efficacy of kaolin in water treatment by incorporating diphenylamine (DPA) and to evaluate its effectiveness in adsorbing lead and copper in wastewater in comparison to natural kaolin (Nat-kaolin). This entailed modifying kaolin with DPA to create DPA-kaolin and conducting comprehensive characterization utilizing a range of techniques, including X-ray diffraction analysis (XRD), scanning electron microscope (SEM), energy dispersion X-ray (EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analysis. The results demonstrated the successful modification of DPA, as evidenced by an increase in BET-specific surface area of about 25 \% (from 66.69 m².g⁻¹ to 71.35 m².g⁻¹), indicating enhanced adsorption capacity. XRD analysis confirmed the composition of the samples, while TGA/DTA indicated changes in water adsorption and dehydroxylation. SEM and EDX illustrated the tubular nature of the clay with a decrease in the amount of Al, about 10.76 \%, and the amount of Si, about 10.38 \%, on the DPA-kaolin. Notably, the FTIR spectrum of DPA-kaolin showed the presence of new vibration bands at 1248 cm⁻¹, indicating the presence of DPA. In terms of adsorption, the DPA-kaolin exhibited significantly higher maximum adsorption capacities for Pb(II) and Cu(II) compared to the nat-kaolin, with values of 151 μmol/g and 134 μmol/g, respectively.These values were significantly higher than those observed for Nat-kaolin, which demonstrated adsorption capacities of 103 μmol/g for Pb(II) and 91 μmol/g for Cu(II). The adsorption kinetics indicated that the pseudo-second-order kinetic model described the sorption mechanism for both Pb(II) and Cu(II). This was evidenced by the values of R², which were 0.999 and 0.996, respectively. The study provides clear evidence that DPA-kaolin is more effective than Nat-kaolin in removing lead (Pb(II)) and copper (Cu(II)) from wastewater. Through rigorous experimentation, it was observed that DPA-kaolin exhibited notably enhanced adsorption capabilities for both Pb(II) and Cu(II) compared to Nat-kaolin. These findings serve to emphasize the practical importance and potential.}, subject = {Kaolin clay; Water treatment; DPA-Kaolin; Chemical treatment; Adsorption; Isotherms}, language = {en} } @article{DahmaniFellahHeziletal.2025, author = {Dahmani, Maewa 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 = {10.1016/j.jmrt.2025.03.180}, pages = {2297 -- 2316}, year = {2025}, 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.}, subject = {Ti-25Nb-25Mo; Milling time; Bioactivity; Hydroxyapatite; Friction coefficient}, language = {en} } @article{ObrosovFallahHeziletal.2024, author = {Obrosov, Aleksei and Fallah, Mamoun and Hezil, Naouel and Bouras, Dikra and Bouchareb, Nabila and Perez Larios, Alejandro and El-Hiti, Gamal A. and Weiß, Sabine}, title = {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}, series = {Journal of Science: Advanced Materials and Devices}, volume = {9}, journal = {Journal of Science: Advanced Materials and Devices}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2024.100695}, year = {2024}, abstract = {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-25NbxZr [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 density 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.}, subject = {Ti-Nb-Zr alloys; Nanobiomaterials; Tribological behavior; Ringer's solution; Biomedical applications; Ti-Nb-Zr-Legierungen; Nanowerkstoffe; Tribologisches Verhalten; Ringerl{\"o}sung; Biomedizinische Anwendungen; Biomedizin; Nanostrukturiertes Material; Titanlegierung; Zirconium}, language = {en} }