Publications Internationales
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Item Impact of substrate on the formation mechanism of electrodeposited Co–Ni thin films: a comprehensive study of structural, morphological, and magnetic properties(Springer, 2024) Boulegane, Ala; Guittoum, Abderrahim; Hadj Larbi, Abderrahim; Laggoun, Ali; Boudissa, MokhtarIn this work, we investigated the effect of substrate on the structural, morphological, and magnetic properties of electrodeposited CoNi thin films from a chloride bath. Three samples of CoNi films were deposited at room temperature onto different substrates: FTO, ITO, and Cu. Electrochemical studies were performed using cyclic voltammetry experiments. Energy-dispersive X-ray spectroscopy (EDX) showed that all the samples had a cobalt content of more than 80%. X-ray diffraction (XRD) spectra revealed that the films deposited on Cu had a face-centered cubic (FCC) phase, while those deposited on ITO and FTO had a mixture of hexagonal close-packed (HCP) and FCC phases. The lattice parameter (a) and crystallite size (D) were strongly dependent on the substrate. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe the morphology of the films. All the samples had a granular morphology with spherical grains, but the roughness and surface distribution varied with the substrate. The magnetic properties of the films, such as coercivity (Hc) and squareness (S), were investigated using a vibrating sample magnetometer (VSM). The results showed that Hc and S were both affected by the substrate and the film composition. Overall, our results showed that the substrate had a significant effect on the structural, morphological, and magnetic properties of electrodeposited CoNi thin films. These findings could be used to design and optimize CoNi thin films for specific applications.Item Effect of Fe content on the structural and magnetic properties of ternary (Ni 60 Co 40 ) 100-x Fe x nanomaterials synthesized by hydrothermal route(World Scientific, 2024) Gaci, Yacine; Guittoum, Abderrahim; Hemmous, Messaoud; Martínez-Blanco, David; Gorria, Pedro; Blanco, Jesús A.; Aouaroun, TaharThe effect of iron content on the structure, morphology and magnetic properties of (Ni60Co40)100-xFex powders synthesized by hydrothermal method has been studied. Several samples have been elaborated for different Fe content (x = 0, 3, 5, 7, 10 and 13.5). The as- prepared samples have been characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometry (VSM). From XRD spectra and for all Fe content, we have shown the presence of both face centered cubic (FCC) and Hexagonal (HCP) nanosized phases. The lattice parameter increases with increasing Fe content and the grains size varies with Fe content to reach a minimum value of 32 nm for (Co40Ni60)90Fe10. From hysteresis curves, we have extracted the saturation magnetization, Ms, and the coercivity, Hc. We noticed that Ms increases and then decreases as a function of Fe content. The values of Hc vary from 156 Oe to 186 Oe depending on the particles shape.Item Structural, morphological, and magnetic properties of electrodeposited coNi thin films on the FTO substrate(Springer, 2022) Boulegane, Ala; Guittoum, Abderrahim; Laggoun, Ali; Boudissa, Mokhtar; Hemmous, MessaoudCoNi films were elaborated by electrodeposition onto FTO substrates using a chloride bath with a metallic ion molar ratio [Co2+]/[Ni2+] equals 1/1. Three samples were elaborated for different potentials ranging from −1.6 to −1.5 V. The structure and the morphology of CoNi films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The chemical compositions are obtained using energy dispersive X-ray (EDX) and the magnetic properties were studied using a vibrating sample magnetometer (VSM). From X-ray diffraction, we have shown the presence of the FCC phase of CoNi binary alloy with a well-pronounced texture along the < 111 > , < 200 > , and < 220 > planes for all samples. We have found that the applied potential has an influence on crystallite sizes. Besides, a moderate change in the lattice parameter has been observed with increasing applied potential. The AFM images show that the applied potential changes the morphology and the surface roughness of CoNi films. In addition, the SEM images confirm the granular morphology of CoNi deposits and show a good relationship between voltage and grain size. The EDX spectrums confirm the deposition of the cobalt and the nickel on the FTO substrate and show the precedence deposition of Co compared with Ni. The extracted coercive field Hc and squareness from the hysteresis loops explained the good correlation between the magnetic and structural properties of CoNi thin filmsItem Nanocrystalline cellulose from microcrystalline cellulose of date palm fibers as a promising candidate for bio-nanocomposites : isolation and characterization(MDPI, 2021) Hachaichi, Amina; Kouini, Benalia; Kian, Lau Kia; Asim, Mohammad; Fouad, Hassan; Jawaid, Mohammad; Sain, MohiniDate palm fiber (Phoenix dactylifera L.) is a natural biopolymer rich in lignocellulosic components. Its high cellulose content lends them to the extraction of tiny particles like microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC). These cellulose-derived small size particles can be used as an alternative biomaterial in wide fields of application due to their renewability and sustainability. In the present work, NCC (A) and NCC (B) were isolated from date palm MCC at 60 min and 90 min hydrolysis times, respectively. The isolated NCC product was subjected to characterization to study their properties differences. With the hydrolysis treatment, the yields of produced NCC could be attained at between 22% and 25%. The infrared-ray functional analysis also revealed the isolated NCC possessed a highly exposed cellulose compartment with minimized lignoresidues of lignin and hemicellulose. From morphology evaluation, the nanoparticles’ size was decreased gradually from NCC (A) (7.51 nm width, 139.91 nm length) to NCC (B) (4.34 nm width, 111.51 nm length) as a result of fragmentation into cellulose fibrils. The crystallinity index was found increasing from NCC (A) to NCC (B). With 90 min hydrolysis time, NCC (B) showed the highest crystallinity index of 71% due to its great cellulose rigidity. For thermal analysis, NCC (B) also exhibited stable heat resistance, in associating with its highly crystalline cellulose structure. In conclusion, the NCC isolated from date palm MCC would be a promising biomaterial for various applications such as biomedical and food packaging applicationsItem Morphology and thermal properties of Nano-Blends based on cellulose acetate butyrate, poly (ethyl methacrylate) and an organically modified Algerian bentonite(Wiley-VCH Verlag, 2019) Kadi, Souad; Ouaad, Kamel; Djadoun, Said; Vincent, Luc; Sbirrazzuoli, NicolasPoly (ethyl methacrylate)/Cellulose acetate butyrate/organically modified Algerian Bentonite nano‐blends (PEMA/CAB/OMMT) are prepared via solution intercalation method. Transmission electron microscopy (TEM) investigations reveal that depending on the OMMT loading, intercalated and exfoliated silicate layers nano‐blends were obtained. These nano‐blends exhibit an overall improved thermal stability compared to the pure (PEMA/CAB) blend as evidenced by thermogravimetric analysis (TGA)Item Extraction and characterization of microcrystalline cellulose from date palm fibers using successive chemical treatments(Springer, 2021) Hachaichi, Amina; Kouini, Benalia; Kian, Lau Kia; Asim, Mohammad; Jawaid, MohammadItem Some physicochemical and morphological characterizations of three varieties of Algerian common dates(European Journal of Scientific Research, 2007) Chibane, H.; Benamara, S.; Noui, Y.; Djouab, A.The date palm is a typical plant of the arid and semi arid areas. Unfortunately in fact they are not all the varieties that profits from an economic interest except for Deglet-Nour. Thus, it represents a danger to the genetic inheritance and the biodiversity. The three varieties studied in this work are: Mech-Degla, Degla-Beida and Frezza, which are common varieties cultivated in the south of Algeria. They are characterized by a good availability and an interesting aptitude for the conservation. In this work (included in our project consisting in the valorization of the common local dates) were presented only the obtained first results. The morphological characteristics (weight of whole date, pea of pulp (pulpit), weight of the seed, length and width of whole date and the seed, pulp/seed ratio, pulp/date ratio, seed/date ration) are given. The physicochemical parameters studied are: pH, ashes, flavonoid, minerals and antioxidant activity. All three varieties are particularly rich in minerals (K, Ca, Na, Zn, Fe, Cu and Mn), in flavonoïd. Concerning the antioxidant activity, different cultivars is endowed with an extraordinary capacity (61.82, 61.56 and 61.61% respectively for Mech-Degla, Degla-Beida and Frezza). © EuroJournals Publishing, Inc. 2007Item Influence of natural weathering on the physical properties of compatibilized blends of poly(propylene)/polyamide-6(Wiley Online Library, 2012) Mouffok, Samir; Kaci, M.; Peuvler-Disdier, E.; Aliouche, D.