La escritura árabe, entre el arte de la caligrafía y la epigrafía islámica.

El presente trabajo se centra en resaltar una de las manifestaciones más originales del arte islámico,la caligrafía árabe, cuyo recorrido histórico-lingüístico ha sido ampliamente documentado desdelos primeros eruditos árabes hasta los investigadores academicistas actuales, ambos grupos hanligado este fenómeno artístico con el islam.En este documento, sin ánimo de ser pretencioso, presento un análisis descriptivo de la evoluciónde dicho arte con un afán de ampliar la perspectiva en la cual se ha encasillado a la escritura árabeen el mundo del arte como un mero complemento del arte islámico, especialmente en su facetaepigráfica. Por ello, pretendo elaborar una tesis recopilatoria de los conocimientos artísticos ylingüísticos de la escritura árabe basándome en el estudio y la interpretación de fuentes epigráficas,documentales, numismáticos, de cerámica, manuscritos por parte de arabistas nacionales yextranjeros, además de algunas ponencias cuyas aportaciones al tema enriquecen el contenido deldocumento. <br /

Polymer-Clay Nanocomposites: Exfoliation and Intercalation of Organophilic Montmorillonite Nanofillers in Styrene–Limonene Copolymer

Nanocomposites from Styrene-Limonene copolymers and Algerian organophilic-clay named Maghnite-CTA+ (Mag-CTA+), were prepared by in-situ polymerization using different amounts (2, 5, and 10% by weight) of clay and Azobisisobutyronitrile (AIBN) as a catalyst. The Mag-CTA+ is an organophilic silicate clay prepared through a direct exchange process, using Cetyltrimethylammonuim bromide (CTAB) in which it used as green nano-filler. The preparation method of nanocomposites was studied in order to determine and improve structural, morphological and thermal properties of Sty-Lim copolymer. The struc ture and morphology of the obtained nanocomposites (Sty-Lim/Mag) were determined using Fourier trans form infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). The analyses confirmed the chemical modification of clay layers and the intercalation of Sty-Lim copolymer within the organophilic clay sheets. Exfoliated structure was obtained for the lower amount of clay (2 wt %), while intercalated structures were detected for higher amounts of clay (5 and 10 wt %). The thermal properties of the obtained nanocomposites were studied by thermogravimetric analysis (TGA) and show a significant improvement in the thermal stability compared with the pure copolymer. The obtained nanocomposites show an optimal degradation temperature of 320°C.info:eu-repo/semantics/publishedVersio

Ultrasound Assisted Synthesis of Polylimonene and Organomodified-clay Nanocomposites: A Structural, Morphological and Thermal Properties

Polylimonene-clay nanocomposites (PLM-Mag 2, 3, 6 and 10% by weight of clay) were prepared by mixing Maghnite-CTA+ (Mag-CTA+) and polylimonene (PLM) in solution using ultrasonic irradiation. The catalyst preparation method were studied in order to determine and evaluate their structural, morphological and thermal properties. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process, using green natural clay of Maghnia (west of Algeria) called Maghnite. The Algerian clay was modified by ultrasonic-assisted method using cetyltrimethylammonuim bromide (CTAB) in which they used as green nano-reinforcing filler. Polylimonene was obtained by the polymerization of limonene, using Mag-H+ as a catalyst. The morphology of the obtained nanocomposites was studied by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) shows that the nanocomposites have a high degradation temperature (200−250 °C) compared with the pure polylimonene (140 °C). The analyses confirmed the chemical modification of montmorillonite layers and their uniformly dispersion in the polylimonene matrix. Exfoliated structures were obtained for low amounts of clay (2 and 3% by weight), while intercalated structures and immiscible regions were detected for high amounts of clay (6 and 10% by weight). Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Synthesis and Characterization of PANI and Block Copolymer PANI-b-PEO Catalyzed by Maghnite (AlgerianMMT): Electrical and Electronic Domain

Polyaniline (PANI) and its block copolymer (PANI-PEO2000) has been prepared under effect of Maghnite-H+ (Algerian MMT) in different weight percentage (wt %) by cationic polymerization method. The structure of PANI and PANI-PEO2000 is predicted by the FT-IR and 1HNMR spectra. The thermal stability of homopolymer and block copolymer is confirmed by difference scanning calorimetry and analysis thermogravimetry. So after this results we can suggest that our heterogeneous catalyst called maghnite (Algerian MMT) can modified the morphology and the physical chemical properties of polyaniline (PANI) and its homolog block polyaniline-b-poly ethylene oxide (PANI-b-PEO2000) in the mild conditions under microwave irradiation

A step-by-step synthesis of triazole-benzimidazole-chalcone hybrids: Anticancer activity in human cells+

Novel series of triazole-benzimidazole-chalcone hybrid compounds have been synthesized via click chemistry, between different azide derivatives and substituted benzimidazole terminal alkynes bearing a chalcone moiety. The starting alkynes are prepared via base-catalysed nitrogen alkylation of pre-synthetized benzimidazole-chalcone substrates. All the intermediates as well as the final products are fully characterized by 1D and 2D NMR and mass spectrometry techniques. HMBC correlations permits the identification of a unique 1,4-disubstitued triazole-benzimidazole-chalcone isomer. Evaluation of the anti-proliferative potential in breast and prostate cancer cell lines showed that the presence of chloro substituents at the chalcone ring of the triazole-benzimidazole-chalcone skeleton enhanced the cytotoxic effects. The benzyl group linked to the 1,2,3-triazole moiety provides more antiproliferative potential.publishe

Structural and Chemical Analysis of New Cement Based on Eggshells and Sand from Dunes (Southern West of Algeria) Stabilized by PET

In this chapter, we present our study of geopolymers and hybrid geopolymers synthesized with treated fly ash from eggshells (FAES) and sand from the dunes of southern Algeria using activators such as NaOH and Na2SiO3, respectively, in addition to the organic polymer polyethylene terephthalate (PET). Several parameters have been modified, such as alkali concentration and percentage of activators and PET, with the objective to improve the quality of the desired geopolymers and hybrid geopolymers. The main objective of this work is to study the use of waste PET in the matrix of this new material to replace Portland cement, which is widely used today, as well as develop ecological building materials that are durable and lightweight and prevent chemicals from attacking old structures. Through optical and electron microscopy, we studied the effect of the addition of PET on the structure of our geopolymer material and on the bond and interface areas between the aggregates and the matrix. The microstructural analysis discussed here refers to specimens containing 5% PET by weight. We observed that PET contents significantly altered the structure and morphology of the samples

Synthesis and Characterization of Copolymers and Nanocomposites from Limonene, Styrene and Organomodified-Clay Using Ultrasonic Assisted Method

In the present work, we report a simple synthesis method for preparation of copolymers and nanocomposites from limonene and styrene using clay as a catalyst. The copolymerization reaction is carried out by using a proton exchanged clay as a catalyst called Mag-H+. The effect of temperature, reaction time and amount of catalyst were studied, and the obtained copolymer structure (lim-co-sty) is characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (1H-NMR) and differential scanning calorimetry (DSC). The molecular weight of the obtained copolymer is determined by gel permeation chromatography (GPC) and is about 4500 g·mol−1. The (lim-co-sty/Mag 1%, 3%, 7% and 10% by weight of clay) nanocomposites were prepared through polymer/clay mixture in solution method using ultrasonic irradiation, in the presence of Mag-CTA+ as green nano-reinforcing filler. The Mag-CTA+ is organophilic silicate clay prepared through a direct exchange process, using cetyltrimethylammonuim bromide (CTAB). The prepared lim-co-sty/Mag nanocomposites have been extensively characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). TEM analysis confirms the results obtained by XRD and clearly show that the obtained nanocomposites are partially exfoliated for the lower amount of clay (1% and 3% wt) and intercalated for higher amounts of clay (7% and 10% wt). Moreover, thermogravimetric analysis (TGA) indicated an enhancement of thermal stability of nanocomposites compared with the pure copolymer

Green Copolymers and Nanocomposites from Myrcene and Limonene Using Algerian Nano-Clay as Nano-Reinforcing Filler

In this work, we report a new facile method for the preparation of myrcene-limonene copolymers and nanocomposites using a Lewis acid as a catalyst (AlCl3) and organo-modified clay as a nano-reinforcing filler. The copolymer (myr-co-lim) was prepared by cationic copolymerization using AlCl3 as a catalyst. The structure of the obtained copolymer is studied and confirmed by Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance spectroscopy, and Differential Scanning Calorimetry. By improving the dispersion of the matrix polymer in sheets of the organoclay, Maghnite-CTA+ (Mag-CTA+), an Algerian natural organophilic clay, was used to preparenanocomposites of linear copolymer (myr-co-lim). In order to identify and assess their structural, morphological, and thermal properties, the effect of the organoclay, used in varyingamounts (1, 4, 7, and 10% by weight), and the preparation process were investigated. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process in which they were used as green nano-reinforcing filler. The X-ray diffraction of the resulting nanocomposites revealed a considerable alteration in the interlayer spacing of Mag-CTA+. As a result, interlayer expansion and myr-co-lim exfoliation between layers of Mag-CTA+ were observed. Thermogravimetric analysis provided information on the synthesized nanocomposites’ thermal properties. Fourier transform infrared spectroscopy and scanning electronic microscopy, respectively, were used to determine the structure and morphology of the produced nanocomposites (myr-co-lim/Mag). The intercalation of myr-co-lim in the Mag-CTA+ sheets has been supported by the results, and the optimum amount of organoclay needed to create a nanocomposite with high thermal stability is 10% by weight. Finally, a new method for the preparation of copolymer and nanocomposites from myrcene and limonene in a short reaction time was developed