Browsing by Author "Amirou, Siham"

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Adsorption of Cr(VI) from aqueous solutions using algerian pinus halepensis tannin foam
(Polymer Society of Korea, 2020) Hamadi, Zeyneb; Hamadi, Zeyneb; Kebir, Mohammed; Amirou, Siham; Essawy, Hisham; Pizzi, Antonio
In this study, new adsorbent tannin foam was prepared from Algerian natural pinus halepensis tannin (APTF). The prepared material has been used as an efficient and environmentally friendly adsorbent to remove chromium (Cr(VI)), which is considered as the most toxic pollutant in wastewater. The different features of the adsorbent in terms of the structural and morphological characteristics were studied. The impact of different factors on the adsorption process, such as pH, adsorbent mass, initial Cr(VI) concentration, and temperature, was investigated. The data obtained from the Cr(VI) adsorption revealed an improvement of the removal efficiency with increasing the adsorbent dose, the pH had a notable effect on Cr(VI) adsorption capacity, whereas the effectiveness decreased by rising the initial metal concentration. In addition, it was observed that adsorption efficiency enhanced with increasing temperature, indicating that the adsorption was endothermic and spontaneous in nature. Moreover, the results were best represented by the pseudo-second order kinetic model and the Langmuir isotherm model (qm = 400 mg·g-1) at 293 °K and pH ~2
Characterization of cellulose prepared from some Algerian lignocellulosic materials (zeen oak wood, Aleppo pine wood and date palm rachis)
(Springer, 2015) Haddadou, Imane; Aliouche, Djamel; Brosse, Nicolas; Amirou, Siham
Effects of corona discharge treatment on the mechanical properties of biocomposites from polylactic acid and Algerian date palm fibres
(2013) Amirou, Siham; Zerizer, A.; Haddadou, Imane; Merlin, A.
In this paper, biocomposites materials based on date palm fibres (untreated or treated with corona discharge) as reinforcing elements and polylactic acid matrices were prepared and characterized. The objective of this study was to evaluate the mechanical properties of these biocomposites by modification of date palm fiber by using corona discharge treatment which results in a surface oxidation. The morphology of processed biocomposites was studied by scanning electron microscopy. It was found that treated fibers of the reinforced composite showed superior mechanical properties as compared with untreated fiber reinforced composites due to the enhanced adhesion between the treated date palm fiber and the polylactic acid matrix. Changes in the surface chemistry were investigated with Fourier Transform infrared spectroscopy. Moreover, morphological studies by scanning electron microscopy demonstrated that better adhesion between the treated fiber and the matrix was achieved. Such studies are of great interest in the development of environmentally friendly composites from biodegradable polymers
Etude et mise au point de composite à base de la matière fibreuse du palmier dattier Phoenix dactylifera L
(2015) Amirou, Siham
Face aux besoins de plus en plus importants en matériaux performants et à la nécessité d'une utilisation rationnelle et durable des ressources naturelles disponibles, l'industrie des matériaux composites notamment celle composite à base des fibres ,des panneaux de fibres et des panneaux de particules s'est particulièrement développée en utilisant comme matrice des résines thermodurcissables à base de formaldéhyde tels que l'urée formaldéhyde, le phénol formaldéhyde, la mélamine urée formaldéhyde, etc. Malheureusement, ces matériaux génèrent dans leur mise en œuvre et tout au long de leur vie du formaldéhyde qui est un produit volatil toxique. L'impérieuse nécessité de protection de la santé environnementale et la prévention de la toxicité avérée des émissions de formaldéhyde des liants conventionnels des panneaux de particules nous amène à diriger notre investigation vers le développement de nouveaux liants à faible rejet de formaldéhyde ou sans émission de formaldéhyde à travers la mise en œuvre de ressources naturelles. Ainsi la ressource bois, qui est la matière première de choix pour l'industrie des panneaux de fibres et de particules, se raréfie de plus en plus et se doit donc d'être préservée. Il s'agit d'un impératif de protection de l'environnement qui ouvre ainsi la voie à la valorisation de matières premières alternatives telles les ressources lignocellulosiques dont un exemple des plus significatifs est le palmier dattier . C'est ce dernier que nous avons choisi pour ce travail de thèse en tant que source de particules pour l'élaboration des panneaux de particules et des composites. C'est cette approche que nous avons choisie d'explorer dans ce travail de thèse en partant de l'hypothèse que l'on peut obtenir des panneaux de particules et des composites de résistance mécanique suffisante pour les utiliser comme matériaux à diverses fins en liant des particules de palmier dattier avec des biomolécules adhésives d'origine végétale ou bien avec des colles synthétiques. Le but de ces études est d'évaluer la possibilité d'élaborer des panneaux particules et des composites écologiques ayant de bonnes caractéristique
Hyperbranched poly(amidoamine)s as additives for urea formaldehyde resin and their application in particleboard fabrication
(North Carolina State University, 2015) Zhang, J.; Amirou, Siham; Essawy, H.A.; Pizzi, A.; Gao, Q.; Li, J.
Three types of hyperbranched poly(amidoamine)s (PAMAMs), namely HB(MA-EDA)1, HB(MA-EDA)3, and HB(MA-DETA)1.2, were synthesized and used as modifiers for urea-formaldehyde (UF) resin. Particleboards bonded with these modified UF resins were fabricated and evaluated. The results showed that these PAMAMs caused some adverse effects on UF resin performance. The main problems of PAMAMs were their high buffer capacity and high pH values, which are attributed to the peripheral amino groups at the terminals, both of which had a serious negative influence on UF resin curing. These findings were supported by the gel time measurements in parallel with a predictive investigation on the resins using thermomechanical analysis (TMA). The gel time was prolonged, and the maximum modulus of elasticity (MOE) values decreased with the addition of HB(MA-EDA)3. The use of a strong acid curing agent (HCOOH) could reduce the gel time into a normal range; however the performance of the corresponding particleboards still deteriorated. Therefore, these PAMAMs are considered not suitable for the modification of UF resin when applied as final additives. Beyond all expectations, the modified UF resin that employed very finite amounts of HB(MA-EDA)1 as a pH regulator instead of NaOH yielded a considerable upgrade in performance of the produced particleboards
Investigation of chemical, physical and mechanical properties of algerian date palm wood
(Carl Hanser Verlag, 2014) Amirou, Siham; Zerizer, Abdellatif; Pizzi, Antonio
Particleboards production from date palm biomass
(Springer Berlin Heidelberg, 2013) Amirou, Siham; Zerizer, A.; Pizzi, A.; Haddadou, Imane; Zhou, X.
Date palm biomass is a renewable natural resource that has not widely been utilized in industry. The objective of this study was to examine some chemical properties of date palm trunk and rachis (holocellulose, cellulose, lignin and extractives) and to evaluate their suitability to produce composite panels. Particleboards were produced using trunk and rachis as an alternative raw material for forest products industry in the presence of two types of polycondensation resins (phenol–formaldehyde and melamine urea–formaldehyde) which were selected as binding agents. The panels were tested for their physical (water absorption and thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond strength) properties. The internal bond strength of date palm trunk and date palm rachis based boards met the requirements of the general purpose product standards (EN 312) at 0.70 g/cm3 density. The panels made with phenol–formaldehyde resin showed better performance with respect to the panels made with melamine urea–formaldehyde. In addition, the particleboard made with date palm trunk particles had better quality compared to the particleboard made from date palm rachis particles. Based on preliminary results of this work, raw materials from date palm trunks and rachis can have a promising potential in the manufacture of particleboards and as a substitute for wood in board production
Thermal behaviour of five different date palm residues of algeria by thermogravimetric analysis
(PRO LIGNO, 2013) Amirou, Siham; Haddadou, Imane; Zerizer, A.
Renewable energy has become more important globally especially with the current fuel and economic crisis. Date palm biomasses are highly potential materials for energy resources. The fact that they are renewable and abundantly available are amongst the attractive reasons of employing them as the major source for renewable energy. The purpose of this research was to investigate the thermal behavior of date palm biomass in order to evaluate their usefulness for energy production. In microparticular scale, the thermogravimetric analysis (TGA) is one of the techniques used to determine the thermal properties of five different date palm residues that were studied: (date palm rachis (DPR), date palm trunk (DPT), leaf base (Petiole) (LB), fruitstalk prunings (FP) and liff (LP)). The TGA technique consists to record the lost weight during the increase in temperature from 20°C until 600°C with a 10°C/min heating rate. The thermograms presented a departure phase of free water (from room temperature to 110°C) before the degradation process of the lignocellulosic constituents. The lignin and hemicellulose play an important role on the degradation of lignocellulosic materials at the temperature under 250°C. The degradation of cellulose begins at 250°C and overlaps to that of lignin until 450°C
Utilization of Hydrophilic/Hydrophobic hyperbranched poly(amidoamine)s as additives for melamine urea formaldehyde adhesives
(Wiley, 2015) Amirou, Siham; Zhang, Jizhi; Essawy, H. A.; Pizzi, A.; Zerizer, A.; Li, J.; Delmotte, L.