Saad Lamouri - Academia.edu (original) (raw)

Papers by Saad Lamouri

Journal of Synthetic Lubrication, 1995

The friction of pure polyethylene and acrylate grafed films or mixtures of polyethylene and a pol... more The friction of pure polyethylene and acrylate grafed films or mixtures of polyethylene and a polyiethylene-butylacrylate-maleic anhydride) terpolymer is examined at low speed for sliding on a poly(methylmethacry1ate) (PMMA) or polyvinylchloride (PVC) substrate. In all cases, the friction coefficient p at equilibrium is proportional to the adhesion energy of the same films as determined by a peel test. This study shows how much for smooth surjimes, interjiacial and mechanical properties intervene simultaneously in polymer-polymer friction.

Journal of Alloys and Compounds, 2012

Hybrid organic/inorganic electromagnetic absorbing materials (EMAMs) based on polyaniline (PANI) ... more Hybrid organic/inorganic electromagnetic absorbing materials (EMAMs) based on polyaniline (PANI) and magnetite (Fe 3 O 4) fillers dispersed in epoxy resin matrix were successfully prepared for electromagnetic applications. The effects of PANI and Fe 3 O 4 loading on permittivity, permeability and microwave absorption properties were studied. The structure and the morphology of the elaborated composites were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electromagnetic properties and absorbing behaviors were performed over frequency range of 12.4-18 GHz (Ku-band). The results show that synthesis parameters such as amount and particle size of PANI and used Fe 3 O 4 affect significantly the morphology, the conductivity, and the microwave absorption properties of the final materials. It was revealed that the electromagnetic parameters were higher in hybrid PANI/magnetite/epoxy resin than in dielectric PANI/epoxy resin composites. The permittivity and the permeability parameters increased to high values with the rate of fillers in the composite and remained constant with the frequency. A minimum reflection coefficient (RC) of −42 dB was observed at 16.3 GHz with a thickness around 1 mm for composites containing 15% of PANI and 10% of Fe 3 O 4 (ε = 10) and −37.4 dB at 14.85 GHz for the composite of 15% of PANI and 25% of Fe 3 O 4 (ε = 17). However, a composite made with only 20% of PANI (ε = 8.5) showed a minimum reflection coefficient of −11 dB at 18 GHz with the same thickness. The possibility to modulate the electromagnetic properties of the composite materials is of a great interest to fabricate microwave absorbing and electromagnetic shielding materials with high performances.

Journal of Applied Polymer Science

The objective of this work is to initiate the discussion about multiphysics relationships between... more The objective of this work is to initiate the discussion about multiphysics relationships between the molten and solid states of high-density polyethylene (HDPE). The extrusion and the injection processes are employed to prepare samples, and the experimental procedures, using differential scanning calorimetry, dynamic thermomechanical analysis (DMTA), thermal gravimetric analysis, and rheological measurements, are defined to choose the optimal variables. After different characterizations, the extrusion and injection temperatures of 220 and 230 C have been chosen. To investigate the viscoelastic behavior of HDPE, the DMTA is used. To perform the high strain rate tensile tests, tensile machine was equipped with a specific furnace. Two temperatures, −20 and 20 C, with strain rates varying from 0.001 to 100 seconds −1 were used to compare the flow characteristics. Results showed that by increasing the strain rate the molecular mobility of the HDPE chains is decreased. In addition, to the tests at −20 C, the increase of Young's modulus can be properly observed, under high strain rates.

Polymer Journal, 2009

In this study, the dibenzoyl-L-tartaric acid (DBTA) was used as doping agent to synthesis polyani... more In this study, the dibenzoyl-L-tartaric acid (DBTA) was used as doping agent to synthesis polyaniline (PANI) by direct oxidative polymerization of a chiral aniline monomer repeat unit. The influence of DBTA on the electrical performances of the polyaniline was studied with the synthesis conditions, particularly the molar ratio of DBTA to aniline and the presence of methanol. The spectral characterization (FT-IR and UV-visible-NIR), the thermal (TGA), electrical properties at macroscopic scale (I-V, C-V curves and the gap) and the morphology of the PANI have been investigated. From the results it's found that synthetic conditions have a great influence on the electrical properties of PANI-DBTA. In addition polyaniline micro-fibres can be obtained when using methanol as a solvent of DBTA.

Optical Materials, 2010

This paper deals with the preparation of polyaniline (PANi) covalently grafted onto aniline-termi... more This paper deals with the preparation of polyaniline (PANi) covalently grafted onto aniline-terminated porous silicon (PSi) substrate. Aniline-terminated PSi surface was obtained in a two-steps procedure. First, oxidized PSi surface was reacted with 3-bromopropyltrichlorosilane to yield a brominated surface. Aniline-terminated PSi surface was realized by reacting brominated PSi layer with aniline molecules at 60°C for 24 h. The aniline moieties anchored onto the PSi surface were used as reactive sites for graft polymerization of aniline monomer. The composition and morphology of the resulting surfaces were examined by Fourier transform infrared spectroscopy (FT-IR), secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM). Furthermore, the optical properties of all functionalized materials involved in the synthesis protocol were characterized using photoluminescence (PL).

Conducting polymer composites based on conductive organic/inorganic fillers dispersed in insulati... more Conducting polymer composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been widely investigated during last decade because of their widespread applications such as electromagnetic shielding materials, microwave absorbers and electrostatic discharges. In this context, the aim of the present work is the elaboration of composites based on polyaniline (PANI) and polyurethanes (PU). The polyurethanes were made respectively from aliphatic (HDI) and aromatic (TDI) polyisocyanate, in order to check the influence of the nature of the isocyanate on the structural, thermal and dielectric properties of the composites. The PANI-HCl was synthesized following an internally optimized process which has allowed us to obtain high conductivity value around 15 S/cm. This later has pushed us to prepare a formulation composites based on (PANI/PU-HDI) and (PANI/PU-TDI) with different concentrations of PANI ranging from 0 to 30 %wt. The composites percolation thresho...

Polyaniline free-standing films behavior has been investigated by electrical measurements, spectr... more Polyaniline free-standing films behavior has been investigated by electrical measurements, spectral, thermal and morphological analyzes. Two categories of thin films were elaborated. The first one represents films containing intrinsic conducting polymer, Polyaniline (PANI), doped by dipping method in sulfanilic acid solutions for various period of time. The second category contains conducting polymer composite; Polyaniline-Polyvinylchloride (PANI/PVC), prepared by co-dissolution method using sulfanilic acid as a doping agent and N-methylpyrrolidone (NMP) as solvent and deposited on glass substrate using the spin coating technique. The effect of doping time, PANI fraction and film thickness on the conductivity has been studied principally by electrical measurements.

Journal of the Serbian Chemical Society, 2015

ABSTRACT In this study, we propose a novel conducting and soluble polyaniline salt prepared by ch... more ABSTRACT In this study, we propose a novel conducting and soluble polyaniline salt prepared by chemical polymerization in the presence of new doping agent (IAs). This last is prepared by sulphonation of itaconic acid (IA) with concentrated sulphuric acid in THF. The obtained doped polyaniline (PANI-IAs) is extremely soluble in dimethyl sulfoxyde (DMSO) at room temperature, in which the solubility reach 44 mg mL-1. The conductivity measurement of doped polyaniline powder precipitated in THF as dispersing medium gave a value of 0.13 S cm-1 when the emeraldine base form of polyaniline is fully protonated. The polyaniline salt sample is characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction, UV-Visible spectra and FTIR spectra.

L’utilisation de la polyaniline (PANI) dans la réalisation des dispositifs semi-conducteurs devie... more L’utilisation de la polyaniline (PANI) dans la réalisation des dispositifs semi-conducteurs devient de plus en plus intéressante, dans ce contexte, nous avons élaboré une diode de Shottky en réalisant une jonction métal/PANI. La polyaniline est synthétisée par la méthode de la polymérisation oxydative dans le méthanol. Le dopage a été effectué directement par l’acide chiral di-benzoyl-L-tartarique (DBTA). La polyaniline obtenue est caractérisée par des méthodes spectrales (FTIR et UV-visible NIR), thermique (ATG). Les propriétés électriques, I-V et C-V ainsi que le gap optique ont été étudiés. La jonction métal/PANI est réalisée avec un dépôt d’aluminium. La caractérisation électrique de cette jonction a abouti à la réalisation d’une diode Shottky.

Journal of Applied Polymer Science, 2014

ABSTRACT Polymer blends based on nanostructured polyaniline (PANI) doped with hydrochloric acid (... more ABSTRACT Polymer blends based on nanostructured polyaniline (PANI) doped with hydrochloric acid (HCl) and para-toluene sulfonic acid (PTSA) introduced into aliphatic polyurethane matrix (PU) are synthesized to produce flexible thin composite films for microwave absorbers. The effects of dopant type, PANI content and film thickness on morphologies, dielectric and microwave absorption properties in the X-band are studied. It reveals that real and imaginary parts of the complex permittivity are proportional to filler concentrations and type of doped PANI. The PANI-PTSA/PU films show higher permittivity and better microwave absorbing properties than PANI-HCl/PU for the same weight fraction of PANI. The minimum reflection loss RL(dB) values for the PANI-PTSA/PU are −37 dB at (20% PANI and 11.6 GHz) and −30 dB at (15% PANI and 11.3 GHz) for thicknesses of 1.2 and 1.6 mm, respectively. These high values of reflection losses make the obtained lightweight and flexible composites promising radar absorbing materials (RAM). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40961.

Bulletin of Materials Science, 2015

ABSTRACT The purpose of this study was to obtain poly(furfuryl alcohol) nanocomposites with Alger... more ABSTRACT The purpose of this study was to obtain poly(furfuryl alcohol) nanocomposites with Algerian organically modified clay (termed 12-montmorillonite). The formation of poly(furfuryl alcohol) was confirmed by infrared spectroscopy (IR); the prepared nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The evolution of mechanical properties was also studied. The obtained results confirm the intercalation of molecules of salt in the clay layers, and a good interaction with the polymer, showing the formation of intercalated and/or exfoliated structures. The nanocomposites showed higher thermal stability compared to pure polymer, and the mechanical properties presented interesting and promising results.

Journal of the Serbian Chemical Society, 2015

This work presents the synthesis and characterization of soluble and conducting polyaniline PANI-... more This work presents the synthesis and characterization of soluble and conducting polyaniline PANI-PIA according to chemical polymerization route. This polymerization pathway leads to the formation of poly(itaconic acid) doped polyaniline salts, which are highly soluble in a number of mixtures between organic common polar solvents and water, the solubility reaches 4 mg mL -1 . The effect of synthesis parameters such as doping level on the conductivity and the study of solubility and other properties of the resulting PANI salts were also undertaken. The maximum of conductivity was found equal to 2.48×10 -4 S cm -1 for fully protonated PANI-EB. In addition, various characterizations of the synthesized materials were also done with the help of viscosity measurements, UV-vis spectroscopy, XRD, FTIR and finally TGA for the thermal properties behaviour.

Oriental Journal of Chemistry, 2013

Bulletin of Chemical Reaction Engineering & Catalysis, 2014

The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H + was reported. Mag... more The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H + was reported. Maghnite-H + is a montmorillonite silicate sheet clay was prepared through a straight forward proton exchange process. The effect of the amount of catalyst, and temperature was studied. Increasing Maghnite-H + proportion and temperature produced the increase in ε-caprolactam conversion. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer inserted into the growing chains with the acyl-oxygen bond scission rather than the break of alkyl-nitrogen bond.

Arabian Journal for Science and Engineering, 2014

Your article is protected by copyright and all rights are held exclusively by King Fahd Universit... more Your article is protected by copyright and all rights are held exclusively by King Fahd University of Petroleum and Minerals. This eoffprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Oriental Journal of Chemistry, 2014

The aim of this work is to obtain an organophilic montmorillonite with Algerian modified clay (te... more The aim of this work is to obtain an organophilic montmorillonite with Algerian modified clay (termed 12-maghnite). The organic surfactant used in this preparation is 12-aminolauric acid. The functionalization of the organophilic clay was confirmed by infrared spectroscopy (IR). The obtained organoclay was characterized by X-ray diffraction (XRD) which shows a remarkable increase of the basal distance that reaches up to 17.62 Å. The transmission electron microscopy analysis (TEM) supports fully the result obtained by XRD analysis. The novelty of this work is the exploitation of local clay that is widely available, inexpensive and has excellent properties and high quality features, which make it the subject of continuing research. These results will be a starting point and an essential reference for a comparative study, with the results of future works concerning the synthesis of Polymer/12-Maghnite nanocomposites.

Research on Chemical Intermediates, 2014

Nylon 6/clay nanocomposites [1, 3, 5, and 10 % (w/w) 12-maghnite based on the e-caprolactam conte... more Nylon 6/clay nanocomposites [1, 3, 5, and 10 % (w/w) 12-maghnite based on the e-caprolactam content] were synthesized by in situ polymerization. 12-maghnite is a montmorillonite silicate sheet clay was prepared through a straightforward exchange process, using a green natural clay from Maghnia (west of Algeria). Fourier transform infrared spectroscopy confirmed the formation of nylon 6. X-ray diffraction and transmission electron microscopy revealed that the modified montmorillonite layers were uniformly dispersed and exfoliated in the nylon 6 matrix for low levels of clay, while intercalated structures and immiscible regions were detected for high levels. Thermogravimetric analysis revealed that the thermal properties of nylon 6/clay nanocomposites were enhanced with increasing 12-maghnite levels ([500°C). Additionally, the nanocomposites showed a remarkable improvement in their mechanical properties compared to pure polymer.

Polymers for Advanced Technologies, 2012

Composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been... more Composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been widely investigated because of their widespread applications such as electromagnetic shielding, electrostatic discharge, and sensors. In this context, novel composite materials based on epoxy resin matrix charged with polyaniline (PANI)doped para-toluene sulfonic acid were elaborated. Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were used to check the structure and the morphology of the samples. Viscoelastic behavior and thermal stability of the composites were explored by dynamic mechanical thermal analysis and thermogravimetric analysis. It was shown that the PANI particles exhibited a partial crystalline structure and were homogeneously dispersed in epoxy matrix. Consequently, this structure affected the thermal stability and viscoelastic properties of the composites. Furthermore, the dielectric and electrical properties were investigated up to 1 MHz. Measurements of dielectric properties revealed that with loading fillers in matrix, the dielectric parameters increased to high values at low frequency then decreased at values around 40 and 32 of real and imaginary parts, respectively, at 1 MHz with 15% of PANI content. . The composite frequency dependence: (a) real permittivity, (b) imaginary permittivity, (c) loss tan δ, (d) the conductivity and PANI loading dependence of (e) permittivity and (f) AC conductivity of polyaniline (PANI)/epoxy resin composites.

Polymer Journal, 2010

Conducting polymer composites, which are simply physical mixtures of an insulating polymer matrix... more Conducting polymer composites, which are simply physical mixtures of an insulating polymer matrix and intrinsically conducting polymers, are promising new materials for various applications such as antistatic coatings, shielding and electromagnetic absorbers. In this context, a novel conducting composite was successfully produced. It is based on epoxy resin and polyaniline (PANI) doped in benzene sulfonic acid, which was used as conducting filler. The effect of PANI loading levels on the structural, morphological, thermal, electrical and dielectric properties was explored using techniques, such as Raman, Fourier transform infrared and ultraviolet-visible-NIR spectroscopy, X-ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry. The electrical behavior and morphology of the synthesized PANI revealed disorder and defects. In addition, as the applied voltage is increased, the current through the sample increases rapidly. The conductivity and dielectric properties were also investigated at room temperature in the frequency range of 1 MHz-1 GHz. The dielectric constant was shown to increase with increased loading at low frequencies and then decreases rapidly, reaching a constant value at higher frequencies. In addition, the AC conductivity of the prepared composites increases with the addition of PANI and is higher at high frequencies. Furthermore, the stability of the composites was found to be influenced by increasing the amount of PANI filler in the matrix.

Journal of Synthetic Lubrication, 1995

The friction of pure polyethylene and acrylate grafed films or mixtures of polyethylene and a pol... more The friction of pure polyethylene and acrylate grafed films or mixtures of polyethylene and a polyiethylene-butylacrylate-maleic anhydride) terpolymer is examined at low speed for sliding on a poly(methylmethacry1ate) (PMMA) or polyvinylchloride (PVC) substrate. In all cases, the friction coefficient p at equilibrium is proportional to the adhesion energy of the same films as determined by a peel test. This study shows how much for smooth surjimes, interjiacial and mechanical properties intervene simultaneously in polymer-polymer friction.

Journal of Alloys and Compounds, 2012

Hybrid organic/inorganic electromagnetic absorbing materials (EMAMs) based on polyaniline (PANI) ... more Hybrid organic/inorganic electromagnetic absorbing materials (EMAMs) based on polyaniline (PANI) and magnetite (Fe 3 O 4) fillers dispersed in epoxy resin matrix were successfully prepared for electromagnetic applications. The effects of PANI and Fe 3 O 4 loading on permittivity, permeability and microwave absorption properties were studied. The structure and the morphology of the elaborated composites were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electromagnetic properties and absorbing behaviors were performed over frequency range of 12.4-18 GHz (Ku-band). The results show that synthesis parameters such as amount and particle size of PANI and used Fe 3 O 4 affect significantly the morphology, the conductivity, and the microwave absorption properties of the final materials. It was revealed that the electromagnetic parameters were higher in hybrid PANI/magnetite/epoxy resin than in dielectric PANI/epoxy resin composites. The permittivity and the permeability parameters increased to high values with the rate of fillers in the composite and remained constant with the frequency. A minimum reflection coefficient (RC) of −42 dB was observed at 16.3 GHz with a thickness around 1 mm for composites containing 15% of PANI and 10% of Fe 3 O 4 (ε = 10) and −37.4 dB at 14.85 GHz for the composite of 15% of PANI and 25% of Fe 3 O 4 (ε = 17). However, a composite made with only 20% of PANI (ε = 8.5) showed a minimum reflection coefficient of −11 dB at 18 GHz with the same thickness. The possibility to modulate the electromagnetic properties of the composite materials is of a great interest to fabricate microwave absorbing and electromagnetic shielding materials with high performances.

Journal of Applied Polymer Science

The objective of this work is to initiate the discussion about multiphysics relationships between... more The objective of this work is to initiate the discussion about multiphysics relationships between the molten and solid states of high-density polyethylene (HDPE). The extrusion and the injection processes are employed to prepare samples, and the experimental procedures, using differential scanning calorimetry, dynamic thermomechanical analysis (DMTA), thermal gravimetric analysis, and rheological measurements, are defined to choose the optimal variables. After different characterizations, the extrusion and injection temperatures of 220 and 230 C have been chosen. To investigate the viscoelastic behavior of HDPE, the DMTA is used. To perform the high strain rate tensile tests, tensile machine was equipped with a specific furnace. Two temperatures, −20 and 20 C, with strain rates varying from 0.001 to 100 seconds −1 were used to compare the flow characteristics. Results showed that by increasing the strain rate the molecular mobility of the HDPE chains is decreased. In addition, to the tests at −20 C, the increase of Young's modulus can be properly observed, under high strain rates.

Polymer Journal, 2009

In this study, the dibenzoyl-L-tartaric acid (DBTA) was used as doping agent to synthesis polyani... more In this study, the dibenzoyl-L-tartaric acid (DBTA) was used as doping agent to synthesis polyaniline (PANI) by direct oxidative polymerization of a chiral aniline monomer repeat unit. The influence of DBTA on the electrical performances of the polyaniline was studied with the synthesis conditions, particularly the molar ratio of DBTA to aniline and the presence of methanol. The spectral characterization (FT-IR and UV-visible-NIR), the thermal (TGA), electrical properties at macroscopic scale (I-V, C-V curves and the gap) and the morphology of the PANI have been investigated. From the results it's found that synthetic conditions have a great influence on the electrical properties of PANI-DBTA. In addition polyaniline micro-fibres can be obtained when using methanol as a solvent of DBTA.

Optical Materials, 2010

This paper deals with the preparation of polyaniline (PANi) covalently grafted onto aniline-termi... more This paper deals with the preparation of polyaniline (PANi) covalently grafted onto aniline-terminated porous silicon (PSi) substrate. Aniline-terminated PSi surface was obtained in a two-steps procedure. First, oxidized PSi surface was reacted with 3-bromopropyltrichlorosilane to yield a brominated surface. Aniline-terminated PSi surface was realized by reacting brominated PSi layer with aniline molecules at 60°C for 24 h. The aniline moieties anchored onto the PSi surface were used as reactive sites for graft polymerization of aniline monomer. The composition and morphology of the resulting surfaces were examined by Fourier transform infrared spectroscopy (FT-IR), secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM). Furthermore, the optical properties of all functionalized materials involved in the synthesis protocol were characterized using photoluminescence (PL).

Conducting polymer composites based on conductive organic/inorganic fillers dispersed in insulati... more Conducting polymer composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been widely investigated during last decade because of their widespread applications such as electromagnetic shielding materials, microwave absorbers and electrostatic discharges. In this context, the aim of the present work is the elaboration of composites based on polyaniline (PANI) and polyurethanes (PU). The polyurethanes were made respectively from aliphatic (HDI) and aromatic (TDI) polyisocyanate, in order to check the influence of the nature of the isocyanate on the structural, thermal and dielectric properties of the composites. The PANI-HCl was synthesized following an internally optimized process which has allowed us to obtain high conductivity value around 15 S/cm. This later has pushed us to prepare a formulation composites based on (PANI/PU-HDI) and (PANI/PU-TDI) with different concentrations of PANI ranging from 0 to 30 %wt. The composites percolation thresho...

Polyaniline free-standing films behavior has been investigated by electrical measurements, spectr... more Polyaniline free-standing films behavior has been investigated by electrical measurements, spectral, thermal and morphological analyzes. Two categories of thin films were elaborated. The first one represents films containing intrinsic conducting polymer, Polyaniline (PANI), doped by dipping method in sulfanilic acid solutions for various period of time. The second category contains conducting polymer composite; Polyaniline-Polyvinylchloride (PANI/PVC), prepared by co-dissolution method using sulfanilic acid as a doping agent and N-methylpyrrolidone (NMP) as solvent and deposited on glass substrate using the spin coating technique. The effect of doping time, PANI fraction and film thickness on the conductivity has been studied principally by electrical measurements.

Journal of the Serbian Chemical Society, 2015

ABSTRACT In this study, we propose a novel conducting and soluble polyaniline salt prepared by ch... more ABSTRACT In this study, we propose a novel conducting and soluble polyaniline salt prepared by chemical polymerization in the presence of new doping agent (IAs). This last is prepared by sulphonation of itaconic acid (IA) with concentrated sulphuric acid in THF. The obtained doped polyaniline (PANI-IAs) is extremely soluble in dimethyl sulfoxyde (DMSO) at room temperature, in which the solubility reach 44 mg mL-1. The conductivity measurement of doped polyaniline powder precipitated in THF as dispersing medium gave a value of 0.13 S cm-1 when the emeraldine base form of polyaniline is fully protonated. The polyaniline salt sample is characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction, UV-Visible spectra and FTIR spectra.

L’utilisation de la polyaniline (PANI) dans la réalisation des dispositifs semi-conducteurs devie... more L’utilisation de la polyaniline (PANI) dans la réalisation des dispositifs semi-conducteurs devient de plus en plus intéressante, dans ce contexte, nous avons élaboré une diode de Shottky en réalisant une jonction métal/PANI. La polyaniline est synthétisée par la méthode de la polymérisation oxydative dans le méthanol. Le dopage a été effectué directement par l’acide chiral di-benzoyl-L-tartarique (DBTA). La polyaniline obtenue est caractérisée par des méthodes spectrales (FTIR et UV-visible NIR), thermique (ATG). Les propriétés électriques, I-V et C-V ainsi que le gap optique ont été étudiés. La jonction métal/PANI est réalisée avec un dépôt d’aluminium. La caractérisation électrique de cette jonction a abouti à la réalisation d’une diode Shottky.

Journal of Applied Polymer Science, 2014

ABSTRACT Polymer blends based on nanostructured polyaniline (PANI) doped with hydrochloric acid (... more ABSTRACT Polymer blends based on nanostructured polyaniline (PANI) doped with hydrochloric acid (HCl) and para-toluene sulfonic acid (PTSA) introduced into aliphatic polyurethane matrix (PU) are synthesized to produce flexible thin composite films for microwave absorbers. The effects of dopant type, PANI content and film thickness on morphologies, dielectric and microwave absorption properties in the X-band are studied. It reveals that real and imaginary parts of the complex permittivity are proportional to filler concentrations and type of doped PANI. The PANI-PTSA/PU films show higher permittivity and better microwave absorbing properties than PANI-HCl/PU for the same weight fraction of PANI. The minimum reflection loss RL(dB) values for the PANI-PTSA/PU are −37 dB at (20% PANI and 11.6 GHz) and −30 dB at (15% PANI and 11.3 GHz) for thicknesses of 1.2 and 1.6 mm, respectively. These high values of reflection losses make the obtained lightweight and flexible composites promising radar absorbing materials (RAM). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40961.

Bulletin of Materials Science, 2015

ABSTRACT The purpose of this study was to obtain poly(furfuryl alcohol) nanocomposites with Alger... more ABSTRACT The purpose of this study was to obtain poly(furfuryl alcohol) nanocomposites with Algerian organically modified clay (termed 12-montmorillonite). The formation of poly(furfuryl alcohol) was confirmed by infrared spectroscopy (IR); the prepared nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The evolution of mechanical properties was also studied. The obtained results confirm the intercalation of molecules of salt in the clay layers, and a good interaction with the polymer, showing the formation of intercalated and/or exfoliated structures. The nanocomposites showed higher thermal stability compared to pure polymer, and the mechanical properties presented interesting and promising results.

Journal of the Serbian Chemical Society, 2015

This work presents the synthesis and characterization of soluble and conducting polyaniline PANI-... more This work presents the synthesis and characterization of soluble and conducting polyaniline PANI-PIA according to chemical polymerization route. This polymerization pathway leads to the formation of poly(itaconic acid) doped polyaniline salts, which are highly soluble in a number of mixtures between organic common polar solvents and water, the solubility reaches 4 mg mL -1 . The effect of synthesis parameters such as doping level on the conductivity and the study of solubility and other properties of the resulting PANI salts were also undertaken. The maximum of conductivity was found equal to 2.48×10 -4 S cm -1 for fully protonated PANI-EB. In addition, various characterizations of the synthesized materials were also done with the help of viscosity measurements, UV-vis spectroscopy, XRD, FTIR and finally TGA for the thermal properties behaviour.

Oriental Journal of Chemistry, 2013

Bulletin of Chemical Reaction Engineering & Catalysis, 2014

The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H + was reported. Mag... more The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H + was reported. Maghnite-H + is a montmorillonite silicate sheet clay was prepared through a straight forward proton exchange process. The effect of the amount of catalyst, and temperature was studied. Increasing Maghnite-H + proportion and temperature produced the increase in ε-caprolactam conversion. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer inserted into the growing chains with the acyl-oxygen bond scission rather than the break of alkyl-nitrogen bond.

Arabian Journal for Science and Engineering, 2014

Your article is protected by copyright and all rights are held exclusively by King Fahd Universit... more Your article is protected by copyright and all rights are held exclusively by King Fahd University of Petroleum and Minerals. This eoffprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Oriental Journal of Chemistry, 2014

The aim of this work is to obtain an organophilic montmorillonite with Algerian modified clay (te... more The aim of this work is to obtain an organophilic montmorillonite with Algerian modified clay (termed 12-maghnite). The organic surfactant used in this preparation is 12-aminolauric acid. The functionalization of the organophilic clay was confirmed by infrared spectroscopy (IR). The obtained organoclay was characterized by X-ray diffraction (XRD) which shows a remarkable increase of the basal distance that reaches up to 17.62 Å. The transmission electron microscopy analysis (TEM) supports fully the result obtained by XRD analysis. The novelty of this work is the exploitation of local clay that is widely available, inexpensive and has excellent properties and high quality features, which make it the subject of continuing research. These results will be a starting point and an essential reference for a comparative study, with the results of future works concerning the synthesis of Polymer/12-Maghnite nanocomposites.

Research on Chemical Intermediates, 2014

Nylon 6/clay nanocomposites [1, 3, 5, and 10 % (w/w) 12-maghnite based on the e-caprolactam conte... more Nylon 6/clay nanocomposites [1, 3, 5, and 10 % (w/w) 12-maghnite based on the e-caprolactam content] were synthesized by in situ polymerization. 12-maghnite is a montmorillonite silicate sheet clay was prepared through a straightforward exchange process, using a green natural clay from Maghnia (west of Algeria). Fourier transform infrared spectroscopy confirmed the formation of nylon 6. X-ray diffraction and transmission electron microscopy revealed that the modified montmorillonite layers were uniformly dispersed and exfoliated in the nylon 6 matrix for low levels of clay, while intercalated structures and immiscible regions were detected for high levels. Thermogravimetric analysis revealed that the thermal properties of nylon 6/clay nanocomposites were enhanced with increasing 12-maghnite levels ([500°C). Additionally, the nanocomposites showed a remarkable improvement in their mechanical properties compared to pure polymer.

Polymers for Advanced Technologies, 2012

Composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been... more Composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been widely investigated because of their widespread applications such as electromagnetic shielding, electrostatic discharge, and sensors. In this context, novel composite materials based on epoxy resin matrix charged with polyaniline (PANI)doped para-toluene sulfonic acid were elaborated. Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were used to check the structure and the morphology of the samples. Viscoelastic behavior and thermal stability of the composites were explored by dynamic mechanical thermal analysis and thermogravimetric analysis. It was shown that the PANI particles exhibited a partial crystalline structure and were homogeneously dispersed in epoxy matrix. Consequently, this structure affected the thermal stability and viscoelastic properties of the composites. Furthermore, the dielectric and electrical properties were investigated up to 1 MHz. Measurements of dielectric properties revealed that with loading fillers in matrix, the dielectric parameters increased to high values at low frequency then decreased at values around 40 and 32 of real and imaginary parts, respectively, at 1 MHz with 15% of PANI content. . The composite frequency dependence: (a) real permittivity, (b) imaginary permittivity, (c) loss tan δ, (d) the conductivity and PANI loading dependence of (e) permittivity and (f) AC conductivity of polyaniline (PANI)/epoxy resin composites.

Polymer Journal, 2010

Conducting polymer composites, which are simply physical mixtures of an insulating polymer matrix... more Conducting polymer composites, which are simply physical mixtures of an insulating polymer matrix and intrinsically conducting polymers, are promising new materials for various applications such as antistatic coatings, shielding and electromagnetic absorbers. In this context, a novel conducting composite was successfully produced. It is based on epoxy resin and polyaniline (PANI) doped in benzene sulfonic acid, which was used as conducting filler. The effect of PANI loading levels on the structural, morphological, thermal, electrical and dielectric properties was explored using techniques, such as Raman, Fourier transform infrared and ultraviolet-visible-NIR spectroscopy, X-ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry. The electrical behavior and morphology of the synthesized PANI revealed disorder and defects. In addition, as the applied voltage is increased, the current through the sample increases rapidly. The conductivity and dielectric properties were also investigated at room temperature in the frequency range of 1 MHz-1 GHz. The dielectric constant was shown to increase with increased loading at low frequencies and then decreases rapidly, reaching a constant value at higher frequencies. In addition, the AC conductivity of the prepared composites increases with the addition of PANI and is higher at high frequencies. Furthermore, the stability of the composites was found to be influenced by increasing the amount of PANI filler in the matrix.