Department of Material Sciences

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Carbon Nanotube Catalytic Deposition Synthesis
(IEEE Journal, 2007) O. Guellati, A. Fonseca, W. Bounour, M. Guerioune, Z. Mekhalif, Joseph Delhalle, A. Benaldjia and Jànos B. Nagy
Carbon nanotubes "CNTs" have been the focus of numerous investigations because of their unique and superior properties that are a consequence of their particular structure. Their synthesis has been receiving much attention for a wide variety of applications. Though, scientists are researching more economic ways to produce these structures with high quality and purity, our aim in this research is to investigate and optimize the results of the CNTs growth process using CCVD technique. Due to its simplicity and low cost, this technique is perfectly suited for the production of nanomaterials for future industrial applications. MWNTs CCVD synthesis was carried out at 700degC in 5 to 120 minutes reaction. It is essentially based on 2 steps process: a catalyst impregnation preparation step followed by CCVD procedure using ethylene decomposition over Fe-Co/MgO support. During this synthesis, impurities were also produced. Thus, subsequent chemical purification steps were required to separate the tubes. Finally, characterization of crude and purified products was performed by TEM, SEM and FESEM focusing on composition, form and purity obtained.
Gas Flow and Temperature Synthesis Dependence on the CNTs structure and yield
(International Journal of Nanoelectronics and Materials, 2010) O. Guellati, S. Detriche, M. Guerioune, Z. Mekhalif and J. Delhalle
Theoretical study of inclusion complexation of 3-amino-5-nitrobenzisothiazole with β-cyclodextrin
(2011) Leila Nouar; Sakina Haiahem; Abdelaziz Bouhadiba; Fatiha Madi
The inclusion process involving β-cyclodextrin (β-CD) and 3-amino-5-nitrobenzisothiazole (ANBT) has been investigated by using the MM+ force field, AM1, PM3, HF and B3LYP theories. In this study we took into account only the stochiometry1:1. The complexation and interaction energies for both orientations considered in this research are reported. All quantum computational methods gave the A orientation as the most favorable in which the guest molecule is totally embedded in the hydrophobic cavity of the cyclodextrin with the NO2 group located near the primary hydroxyls of the β-CD and the NH2 group near the secondary hydroxyls with no hydrogen bonding formation. The negative complexation and interaction energies calculated suggest that the inclusion complexes are stable. HOMO and LUMO orbital investigations confirm the better stability of the A orientation.
Molecular modeling investigation of para-nitrobenzoic acid interaction in β-cyclodextrin
(2011) Leila Nouar; Sakina Haiahem; Abdelazize Bouhadiba; Fatiha Madi; Leila Lagrate
Geometry optimizations of para-nitrobenzoic acid (PNBA)/β-cyclodextrin complex were carried out using MM+, PM3 and density function theory B3LYP/6-31G*. Calculations were performed upon the inclusion complexation of β-cyclodextrin (CD) with neutral (PNBA1) and anionic (PNBA2) species of para-nitrobenzoic acid. The results obtained from both methods consistently indicate that the complex of PNBA2/β-CD (B) is significantly more favorable than the others energetically. The negative enthalpy changes calculated from the statistical thermodynamic calculation suggest that both the inclusion complexation is favored enthalpy-driven process. The geometry of the most stable complex shows that the aromatic ring is deeply self-included inside the hydrophobic cavity of β-CD and also intermolecular hydrogen bonds were established between host and guest molecules. This suggests that hydrophobic effect and hydrogen bond play an important role in the complexation process.
Theoretical study of the inclusion processes of the phenylurea herbicide metobromuron in β-cyclodextrin.
(ANSInet, Asian Network for Scientific Information, 2011) Leila Nouar; Sakina Haiahem; Abdelaziz Bouhadiba; Fatiha Madi; Leila Largate; Fateh Djebloune
We investigated the inclusion process of phenylurea herbicide metobromuron (MB) in beta cyclodextrin (β-CD) with 1:1 stoichiometry using: (1) MM+ force field of molecular mechanics in order to research the lowest energy structure of the inclusion complex. (2) Superior levels of calculations were made such PM3, B3LYP/6-31G*, HF/6-31G* and ONIOM2 methods in order to approach the ideal geometry and provide further insight into the different complexation properties of the guest molecule. The data suggest that: The B orientation is significantly more favourable than the A orientation by an energy difference of 1.02 kcal mol-1 according to PM3 calculations. The geometry of the most stable complex shows that the aromatic ring is deeply self-included inside the hydrophobic cavity of β-CD also an intermolecular hydrogen bond is established between host and guest molecules. The formation of the inclusion complex is predicted to be an enthalpy-driven process in gas phase which is in accord with the experimental results. The statistical thermodynamic calculations by PM3 demonstrate that 1:1 MB/β-CD complex is favored by a negative enthalpy change.
Molecular modeling investigation of para-nitrobenzoic acid interaction in β-cyclodextrin
(2011) Leila Nouar; Sakina Haiahem; Abdelazize Bouhadiba; Fatiha Madi; Leila Lagrate
Geometry optimizations of para-nitrobenzoic acid (PNBA)/β-cyclodextrin complex were carried out using MM+, PM3 and density function theory B3LYP/6-31G*. Calculations were performed upon the inclusion complexation of β-cyclodextrin (CD) with neutral (PNBA1) and anionic (PNBA2) species of para-nitrobenzoic acid. The results obtained from both methods consistently indicate that the complex of PNBA2/β-CD (B) is significantly more favorable than the others energetically. The negative enthalpy changes calculated from the statistical thermodynamic calculation suggest that both the inclusion complexation is favored enthalpy-driven process. The geometry of the most stable complex shows that the aromatic ring is deeply self-included inside the hydrophobic cavity of β-CD and also intermolecular hydrogen bonds were established between host and guest molecules. This suggests that hydrophobic effect and hydrogen bond play an important role in the complexation process.
Theoretical study of inclusion complexation of 3-amino-5-nitrobenzisothiazole with β-cyclodextrin
(2011) Leila Nouar; Sakina Haiahem; Abdelaziz Bouhadiba; Fatiha Madi
The inclusion process involving β-cyclodextrin (β-CD) and 3-amino-5-nitrobenzisothiazole (ANBT) has been investigated by using the MM+ force field, AM1, PM3, HF and B3LYP theories. In this study we took into account only the stochiometry1:1. The complexation and interaction energies for both orientations considered in this research are reported. All quantum computational methods gave the A orientation as the most favorable in which the guest molecule is totally embedded in the hydrophobic cavity of the cyclodextrin with the NO2 group located near the primary hydroxyls of the β-CD and the NH2 group near the secondary hydroxyls with no hydrogen bonding formation. The negative complexation and interaction energies calculated suggest that the inclusion complexes are stable. HOMO and LUMO orbital investigations confirm the better stability of the A orientation.
Theoretical investigation study based on PM3MM and ONIOM2 calculations of β-Cyclodextrin complexes with diphenylamine
(2012) Abdelaziz Bouhadiba; Leila Nouar; Sakina Haiahem; Imene Djilani; Fatiha Madi; DjamelEddine Khatmi
The inclusion complex of b-cyclodextrin (b-CD) and diphenylamine (DPA) was investigated by using PM3MM, DFT, HF and ONIOM2 methods. The most stable structure was obtained at the optimum position and angle. The results indicate that the inclusion complex formed by DPA entering into the cavity of b-CD from its wide side (the secondary hydroxyl group side) is more stable than that formed by DPA entering into the cavity of b-CD from its narrow side (the primary hydroxyl group side). The structures show the presence of several intermolecular hydrogen bond interactions that were studied on the basis of natural bonding orbital (NBO) analysis, employed to quantify the donor–acceptor interactions between diphenylamine and b-CD. A study of these complexes in solution was carried out using the CPCM model to examine the influence of solvation on the stability of the diphenylamine b-CD complex.
Influence of ethanol in the presence of H2 on the catalytic growth of vertically aligned carbon nanotubes
(Appl. Catal. A: Gen., 2012) O. Guellati, I. Janowska, D. Bégin, M. Guerioune, Z. Mekhalif, J. Delhalle, S. Moldovan, O. Ersen and C. Pham-Huu
The vertically aligned multi-walled carbon nanotubes (VA-MWNTs) were synthesized by a catalytic chemical vapor deposition (CCVD) technique, using ferrocene as an iron catalyst precursor and toluene/ethanol mixture with different ratio as a carbon source/etching agent, in the presence of H2. The growth rate, efficiency and the structure of the synthesized tubes were investigated. The CNTs growth rate and quality of tubes significantly improve up to 9 vol.% of ethanol whereas a negative influence was observed for higher ethanol concentration (>17 vol.%). Low ethanol content in the reaction mixture (5 vol.%) results in the highest volume density of the tubes within the array along with highest specific surface area. The synergetic effect of EtOH/hydrogen on the growth rate of VA-MWNTs was observed as well.
Molecular docking study on b-cyclodextrin Interactions of metobromuron and [3-(p-bromophenyl)-1-methoxy-1- methylurea]
(2012-03-04) sakina haiahem; Abdelaziz Bouhadiba; Leila Nouar; Imene Djilani; Fatiha Madi; Djamel Eddine Khatmi
The inclusion process involving b-cyclodextrin (b-cyclodextrin-CD) and phenylurea herbicide metobromuron (MB) has been investigated by using the MM?, PM3, B3LYP, HF, ONIOM2 and NBO methods. The binding and complexation energies for both orientations considered in this research are reported. The geometry of the most stable complex shows that the aromatic ring is deeply selfincluded inside the hydrophobic cavity of b-CD also an intermolecular hydrogen bond is established between hostand guest molecules. This suggests that hydrophobic effect and hydrogen bond play an important role in the complexation process. The statistical thermodynamic calculations by PM3 demonstrate that 1:1 MB/b-CD complex is favored by a negative enthalpy change. Moreover, NBO calculations proved also that are a very useful means to quantify the interaction energies of the hydrogen bonds.
Host-guest inclusion complex between b-cyclodextrin and paeonol: A theoretical approach
(2013) Sakina Haiahem; Leila Nouar; Imen Djilani; Abdelazize Bouhadiba; Fatiha Madi; Djamel Eddine Khatmi
Host-guest interactions of b-cyclodextrin (b-CD) with paeonol (PAE) were simulated using semi-empirical PM3 and both ONIOM2 [(B3LYP/6-31G*:PM3), (HF/6-31G*:PM3)] methods. The results obtained with PM3 method clearly indicate that the complexes formed are energetically favored with or without solvent, the model 1 (PAE entering into the cavity of b-CD from its wide side by OCH3 group) is found more favored than the model 2 (PAE entering into the cavity of b-CD from its wide side by COCH3 group). Finally, natural bonding orbital (NBO) analysis was performed based on ONIOM2 optimized complexes to quantify the donor–acceptor interactions between PAE and b-CD.
Inclusion complexes of ortho-anisidine and b-cyclodextrin: A quantum mechanical calculation
(2013) Imene Djilani; Leila Nouar; Fatiha Madi; Sakina Haiahem; Abdelaziz Bouhadiba; DjamelEddine Khatmi
The structural aspects for the complexation of ortho-anisidine (O-AN)/b-cyclodextrin were explored by using PM6, density function theory B3LYP/6-31G*, M05-2X/6-31G*, B3PW91/6-31G*, MPW1PW91/6-31G*, HF/6-31G* methods and several combinations of ONIOM2 hybrid calculations. Calculations were performed upon the inclusion complexation of b-cyclodextrin (b-CD) with neutral (O-AN1) and cationic (O-AN2) species of ortho-anisidine. The obtained results with PM6 method clearly indicate that the formed complexes are energetically favored, the complex of O-AN2/b-CD in B orientation is significantly more favorable than the others energetically. The structures show the presence of several intermolecular hydrogen bond interactions that were studied on the basis of natural bonding orbital (NBO) analysis, employed to quantify the donor–acceptor interactions between ortho-anisidine and b-CD.
Synthesis and characterization of HDPE/N-MWNT nanocomposite films
(Nanoscale Research Letters (NRL), 2014) F. Chouit, O. Guellati, S. Boukhzar, A. Harat, M. Guerioune and N. Badi
In this work, a series of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) with several weight percentages (0.1, 0.4, 0.8, and 1.0 wt.%) were synthesized by catalytic chemical vapor deposition (CCVD) technique. The N-MWCNTs were first characterized and then dispersed in high-density polyethylene (HDPE) polymer matrix to form a nanocomposite. The HDPE/N-MWCNT nanocomposite films were prepared by melt mixing and hot pressing; a good dispersion in the matrix and a good N-MWCNT-polymer interfacial adhesion have been verified by scanning electron microscopy (SEM). Raman spectroscopy measurements have been performed on prepared samples to confirm the presence and nature of N-MWNTs in HDPE matrix. The X-ray diffraction (XRD) analysis demonstrated that the crystalline structure of HDPE matrix was not affected by the incorporation of the N-MWNTs.
Device Electromagnetic Characterization of GaAs MESFET Transistor
(2014) Houda Amri; Mourad Zaabat
In this paper, an electromagnetic study of MESFET transistor based on iterative method is presented. This method is generating the relationship between the incident and reflected waves from the planar circuits. The WCIP method is developed from the fast modal transform algorithm.
Theoretical investigation to characterize the inclusion complex of a-lipoic acid and b-cyclodextrin
(2015) Imene Djilani; Fatiha Madi; Leila Nouar; Sakina Haiahem; Mohamed Rahim; Djamel Eddine Khatmi; Abdelaziz Bouhadiba
We simulated the docking of a-lipoic acid (a-LA) in b-cyclodextrin (b-CD) using two models. We considered in this study complexes formed by 1:1 host–guest stoichiometry in vacuo and in aqueous phase, using PM6, DFT and ONIOM2 hybrid calculations. The results obtained with PM6 method clearly indicate that the complexes formed are energetically favored with or without solvent, model 2 (a-LA entering the cavity of b-CD from its wide side by COOH group) is found more favored than model 1 (a-LA entering into the cavity of b-CD from its wide side by cyclic group), the preference being greater in the case of ONIOM2 calculations. In addition, NBO analysis gives that mutual interactions between the donor and acceptor orbitals of a-lipoic acid and b-CD plays an important role to the stabilization of such a complex. Finally, 1H nuclear magnetic resonance (NMR) chemical shifts of free and complexed a-LA were calculated by the Gauge-Including Atomic Orbital (GIAO) method and compared with available experimental data. The results of GIAO calculations were analyzed and discussed.
Density functional study of inclusion complex of Albendazole/cucurbit [7]uril: Structure, electronic properties, NBO, GIAO and TD-DFT analysis
(2015) Nora Merabet; Fatiha Madi; Leila Nouar; Sakina Haiahem; DjamelEddine Khatmi
In the present work, we investigate theoretically, the structure and electronic properties of inclusion complex of cucurbit [7]uril(Q[7]) with Albendazole (ABZ) using DFT calculations. Two modes of complexation were taken into consideration and the effect of solvent is explicitly taken into account. The results obtained with B3LYP/6-31G (d) method clearly indicate that the complexes formed are energetically favored with or without solvent. C1 complex (Albendazole entering the cavity of Q[7] by propyl and aromatic groups) is found more favored than C2 complex (Albendazole entering the cavity of Q[7] by carbamate group). 1H nuclear magnetic resonance (NMR) was calculated by the Gauge-Including Atomic Orbital method and compared with available experimental data. Finally, TD-DFT calculations of visible spectra were analyzed and discussed. The theoretical calculation agrees well with that obtained from experimental data.
Removal of Paranitrophenol by Adsorption on Intercalated Natural Clay
(American Scientific Publishers, 2015-11-30) Ouahida Khireddine; Yamina Berredjem; Ridha Djellaibi; Nadia Bensid; A.E.K. Gheid; A. Bouras
The present work aims to the valorization of locally available clay for water remediation. The used raw material is a clay soil from the region of Guelma (Algeria). Several physico-chemical treatments have been realized in order to obtain purified clay. The characterization of the sample clay, performed using XRD, FT-IR, DTA and SEM, showed its morphology and its texture. Furthermore, the results correlated to the structural analysis, demonstrated that this clay is a disordered kaolinite of type 1:1. The adsorption experiments of parnitrophenol (PNP) in aqueous medium have been carried out using the raw kaolinite and the urea-intercalated kaolinite. The results showed that thecapacity of PNP adsorption on the intercalated kaolinite is more important than that of raw material, where it is 11.06 mg·g−1 and 7.90 mg·g−1 for the urea-intercalated kaolinite and the raw kaolinite respectively. The evaluated experimental values of the adsorption isotherms are in agreement with Langmuir and Freundlich models. In all cases, the adsorption kinetics follows the mechanism of pseudo-second order. In addition, the thermodynamic study indicates that the adsorption of PNP on raw kaolinite and urea-intercalated kaolinite is a spontaneous process.
Adsorption of Benzoic and Salicylic Acids Using Sodium and Intercalated Bentonite in Aqueous Solution
(American Scientific Publishers, 2016) Nadia Bensid; Yamina Berredjem; Zhour Hattab; Ridha Djellabi; Ouahida Khiereddine; FarhiHailaimia; Pierre Magri; Ahmed Boulmokh
The aim of this study was to apply a local betonite (Algeria) purified and intercalated with a surfactantnamely dodecyltrimethylammonium bromide (DTMAB) as an adsorbent to remove benzoic acid (BA) and salicylic (SA) which could be present in wastewaters. This intercalation process leads to improve the porous texture of materials that allows adsorbing efficiently organic compounds. The effect of various experimental parameters was investigated using a batch adsorption technique. The equilibrium adsorption data were well described by the Freundlich and Langmuir isotherms. The adsorption kinetics of both acids could be considered as pseudo-first order with internal diffusion.The capacity of DTMA–bentonite for Benzoic acid and Salicylic acid was found to be around 5 and 3.5 times respectively higher than that of Na–bentonite at 45 C. The thermodynamic study showed that the adsorption is not spontaneous and endothermic.
RÉALISATION DES CELLULES SOLAIRES, OPTIMISATION DE STRUCTURES ITO / SEMICONDUCTEURS ORGANIQUES
(African Review of Science, Technolgy and Development, 2016-01) Berredjem, Y; Bouras, A; Hattab, Z; Boulmokh, A; Boutaleb, Y; Bernede, G.C
Ce travail porte sur le développement de cellules solaires photovoltaïques basées sur un empilement de couches organiques donneuses et accepteuses d’électrons. Le dépôt d'une électrode supérieure transparente reste un des verrous technologiques de ces dispositifs. Nous analysons en détail le dépôt sous vide des différentes couches minces qui constituent la cellule solaire. Une procédure fiable et reproductible est proposée. Les propriétés des couches minces et d'interface des films sont étudiées en détail. La réalisation des cellules solaires à base de CuPc/C60 à permis de mettre en évidence les excellentes propriétés et présentent des meilleurs rendements des dispositifs photovoltaïques. Enfin, La réalisation des cellules solaires valide notre technologie. Un effort particulier a porté sur l'optimisation des couches minces organiques déposées sous l’oxyde transparent conducteur (ITO).
Electromagnetic Modeling of Active Circuit using Wave Concept Iterative Process
(2016-06) Houda Amri
The wave concept iterative process is a procedure used for analyses planar circuits, this method consists in generating a recursive relationship between a wave source and reflected waves from the discontinuity plane which is divided into cells. A high computational speed has been achieved by using Fast Modal Transform (FMT). In this paper we study a patch antenna and MESFET transistor, to determine the electromagnetic characteristics of these structures.