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Properties of the chitosan films can be improved by incorporating clay minerals. So, solvent-cast films of the β-chitosan containing stevensite-rich or kaolinitic-illitic clays (up to 50 mass %) were characterized for their structural and mechanical properties. The effects of molecular weight (MW) and deacetylation degree (DD) of chitosan and the clay/chitosan mass ratio on the inhibition growth of Escherichia coli and Staphylococcus aureus were studied using the response surface methodology (RSM). The films consisted of exfoliated/intercalated or flocculated composites, and the electrostatic bonds formed between the functional moieties of the chitosan and the clay particles active sites essentially influenced their mechanical strength. The results of the study using RSM showed that the optimal value of MW required for the inhibition of the bacteria varied according to the film used, and high antibacterial activity necessitated high DD (89–97%).

Edible films and coatings with good mechanical/physical properties are highly required for carrying medical substances and food packaging. So, solvent-cast films of α- or β-chitosan filled with palygorskite, montmorillonite or geopolymer-containing material (GCM), were prepared, and the effects of their clay contents (up to 50 wt.%) on the mechanical/physical properties were assessed. The microstructure of the films was investigated using FT-IR spectroscopy, SEM and thermal analysis. The results showed that, except for the films composed of GCM and β-chitosan, the mechanical properties of the films with limited (up to 5 wt.%) to moderate (5–25 wt.%) amounts of fillers increased as a result of the attractive electrostatic forces formed between the fillers and chitosan functional groups (–NH3+, CH2OH and NHCOCH3). However, due to the occurrence of coarse aggregates, the strength of filler-rich films declined. The addition of fillers led to an increase in porosity and water absorption of the films, but it had irregular effects on their wettability and water vapor transmission rate. These observations as well as the thermal stability of the films were discussed in relation to the characterization results.

Shrimp shells and waste of olive stones were used as feedstock for the preparation of chitosan and activated carbon. The adsorption of CrVI and CrIII species in aqueous solution by the materials prepared and their blend were studied by using the well-known kinetic and isotherm models, Fourier transform infrared spectroscopy and scanning electron microscope. It was demonstrated that the rates of adsorption were controlled by diffusion inside particles and throughout the liquid film, and adsorption occurred spontaneously (− 26

Clay-based materials composed of geopolymers and natural fibbers, among others, could be suitable composites for building construction. So, in this study, composites of a heated kaolinitic-illitic clay and cuttlebone or chitosan (up to 10 mass%) were etched with a NaOH solution (6 M), shaped as briquettes and cured at 83 °C for up to 30 days. The microstructure of the cured composites was investigated, and some of their practical performances were evaluated. The results showed that metakaolinite and illite - to some extent-, and a portion of Na+ ions were involved in the formation of zeolite (chabazite) and Na-carbonate respectively. Moreover, layers of cuttlebone or chitosan were built up around the clay particles, and the thick layers developed in the cuttlebone- and in the chitosan-rich composites affected differently the zeolization process. Chitosan versus cuttlebone favoured zeolization by facilitating the ions mobility, and the illite reactivity. By referring to the mechanical/physical properties of the cured NaOH-etched heated clay, the bending and the compressive strengths of the cured composites as well as their water absorption increased by two-to three times. The strengthening of the composites was related mainly to the reduction of porosity (up to 40% for the cuttlebone-rich composite).

Dropping out of school has been a major concern at the Moroccan university for several years and is apparent in several university reports. 28% to 30% of students drop out in their first year. The risk factors for dropping out are numerous. The risk of dropping out of school is higher for a student from a disadvantageous social background than for those from a privileged background, with identical academic skills. Research shows that many factors, such as anxiety, uncertainty, Lack of guidance, isolation or alienation, academic difficulties, teaching methods and the teachers’ attitude are key determinants of students’ disengagement from their studies. Actions have been taken by the Moroccan government to reduce this phenomenon; particularly in the form of the “Programme d’Urgence” launched by the Ministry (2008-2012), but the situation has not improved significantly.This publication reports the results of a research conducted at the Cadi Ayyad University since 2015. The tool used to run this investigation is a questionnaire while withdrawing their baccalaureate’s degree from the student affairs service, canceling their registration.

On enregistre depuis l’Independance du Maroc, en 1956, une evolution du systeme educatif, consequence de plusieurs reformes de l’organisation de la scolarite, de la formation des professeurs, de la refonte des programmes scolaires et particulierement ceux des disciplines scientifiques. Ces changements ont ete guides par l’intention de considerer l’ecole comme un levier de developpement du pays qui ne pourra jouer pleinement son role que si la democratisation d’acces a l’ecole et aux connaissances est effective pour tous les enfants et egalement tout au long de la vie. La reussite de la scolarisation est ainsi consideree comme un facteur determinant qui permettra au pays de se doter de cadres qualifies, de reussir l’essor economique et social et de reduire substantiellement l’analphabetisme et les ingredients du sous developpement. Dans cet article, nous essayons de decrire les grandes reformes du systeme educatif au Maroc qui se sont succede depuis son Independance, les motivations qui ont conduit aux choix operes et nous tentons d’analyser la progression et les obstacles rencontres dans la scolarisation. Nous prendrons comme exemple celui des sciences.

A series of polyhydroxylated symmetrical macrocycles has been prepared in satisfactory yield by 1:1 condensation of several bis-epoxides with various bis-nucleophiles. Preliminary results are reported, which illustrate the synthesis of crown ethers and oxa-azacrown and oxa-thiacrown compounds.