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Item Synthesis, characterization and swelling behavior of pH-sensitive polyvinylalcohol grafted poly(acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid) hydrogels for protein delivery(Springer, 2023) Hocine, Salima; Ghemati, Djamila; Aliouche, DjamelThe aim of the current study was to fabricate a pH-sensitive hydrogels for controlled release of Bovine serum albumin (BSA) protein. In this research work, polyvinylalcohol grafted poly(acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid) (PVOH-g-poly(AA-co-AMPS)) hydrogels with varying AA/AMPS molar ratio were synthesized through free radical graft copolymerization of partially neutralized acrylic monomers and characterized by Fourier transform infrared spectroscopy, Elemental analysis, X-ray diffraction, and Scanning electron microscopy, thermogravimetric analysis. Then, mechanical proprieties of hydrogels were investigated, and drug release behavior with Bovine serum albumin (BSA) as model drug was studied in vitro. The effect of AA/AMPS molar ratio, pH media on the swelling property of hydrogels was optimized. Results indicated that the strong interaction in the hydrogels resulted in the formation of a more stable copolymer. The high values of the grafting percentage which exceeds 800% confirmed the high performance of the grafting and the successful synthesis. Grafting AMPS onto PVOH/AA improved both thermal stability and mechanical properties of hydrogel. The hydrogel is simultaneous sensitive to pH and ionic strength; the swelling ratio maximizes at pH 6.8 medium and shrinks at pH 1.2, and decreases as the ionic strength increases; the swelling dynamic mechanism was explained well by Fickian diffusion and Schott’s pseudo-second-order models. Different kinetic models were applied, and it has been observed that release profile of BSA best followed the Hixson–Crowell for the release of drug in all release media. However, Zero order and Korsmeyer–peppas models only for pH 1.2 and pH 7.4. The swelling of the hydrogels and release of BSA from the drug loaded hydrogels occurred through non-Fickian diffusion mechanism. It is believed that this hydrogel could be potentially used for localized drug deliveryItem Studies on equilibrium swelling, dye adsorption, and dynamic shear rheology of polymer systems based on chitosan-poly(vinyl alcohol) and montmorillonite(Taylor & Francis, 2019) Amri, Nedjla; Radji, Sadia; Ghemati, Djamila; Aliouche, DjamelChitosan-poly(vinyl alcohol)/clay membranes were prepared by physical blending. Thesehybrid systems were characterized through infrared spectroscopy, microscopy, swelling, andoscillatory rheology. Adsorption of a commercial reactive dye by these membranes was fur-ther studied. Results showed that more stable blend membranes were formed due to thestrong interaction in the polymers. These membranes showed substantial percent swellingin water and shrinking in saline solution. Adsorption analysis showed the ability of theblends to fix organic dyes, and to be used in liquid waste processing. In dynamic rheology,it was observed that all measured viscoelastic properties were influenced by polymer com-position and clay content. For all samples, results show a typical behavior of an entangledsystem in the case of low concentrated macromolecular viscoelastic fluids. The dynamicmoduli exhibited higher values for blends, compared with values of the pure polymers,which is an indication of good stability and tendency of gel formationItem Study of the kinetics adsorption of organic pollutants on modified cellulosic polymer using ultraviolet-visible spectroscopy(2013) Ghemati, Djamila; Aliouche, DjamelWe report a study on the formation of the complex acrylamidomethylated- β-cyclodextrin, then on the grafting on cellulosic polymer. The grafting is initiated by ceric ions Ce(IV) and confirmed by infrared spectroscopy analysis (FTIR). Scanning electron microscopy (SEM) analysis was carried out to evaluate properties of structure and surface of grafted polymers. The experiments of the study of adsorption of balance of phenol and hydroquinone and a reactive dye, acid dyes, and cationic dyes using ultraviolet-visible microscopy were made in aqueous solutions for 24 hours at different pH. Our results indicate formation of a permanent chemical bond between β-cyclodextrin and polymers material. The cellulosic polymers can effectively be modified without significant change in the structural properties. Then, the results of organic pollutants adsorption in aqueous medium show the aptitude of the polymer modified to fix the phenol derivatives and synthetics dyes and used in the processing industrial liquid waste. The differences in adsorption capacities may be due to the effect of dye structure. The negative value of free energy change indicated the spontaneous nature of adsorptionItem Synthesis and characterization of porous materials containing modified cellulose by β-Cyclodextrin for the application in processing industrial liquid waste(2009) Ghemati, Djamila; Aliouche, DjamelThe cellulose made up the principal structure of many plants. The content varies according to the vegetable species, from approximately 40% in wood, to 95-99% in cotton fibers. Several ways are possible to bring an additional function to cellulose: new fibers, modification of the fibrous structure, physical or chemical treatment by a surface treatment. And due to the contribution of functions, the formerly passive cellulose becomes active. Capacity of cyclodextrins to facilitate the inclusion of hydrophobic molecules, and others chemical derivatives like the dyes, can be exploited to obtain new porous materials modify with particular performances. In this work, a porous cellulosic material modifies was obtained by chemical modification and fixing of β-cyclodextrin on polymeric surface. The results were confirmed by infra-red analysis (FTIR) and scanning electron microscopy (SEM). The experiments of adsorption of balance of a reactive dye were made in aqueous solutions for 48 hours. Our results indicate the formation of a permanent chemical bond between the β - cyclodextrin and the fibrous material, and the modification is done without change of the polymer structure, the inclusion of the molecules of dyes in the cavity of cyclodextrin is due to the several interactions. The results of dye adsorption in aqueous medium show the aptitude of porous materials to fix the dangerous industrial dyes, and used in the processing industrial liquid wasteItem Preparation and biological characterization of cellulose graft copolymers(Elsevier, 2010) Dahou, Wassila; Ghemati, Djamila; Oudia, Atika; Aliouche, DjamelAcrylic acid (AA) and acrylonitrile (AN) were graft polymerized onto cellulose fluff pulp using cericammonium nitrate as initiator. The resulting copolymers were saponified with dilute sodium hydroxide and characterized by FT-IR, SEM and TGA. The potential value of the modified cellulose was assessed through measurements of absorbency properties. A fibre-hydrogel was prepared by an addition of a bifunctional monomer, ethyleneglycol dimethacrylate (EDMA) used for grafting. In second approach, biocide cellulose carbamate was prepared by impregnating the fibres in aqueous thiourea solution and subsequent grafting with acrylonitrile. Antimicrobial activity of the treated cellulose sample was studied against Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis according to AATCC test method 100–1999. The results show that the treated fibre gives higher antimicrobial activity. The strong antimicrobial functions achieved on modified fibres, proved that the synthesized biomaterial was effective, very simple and practical to the textile finishing industryItem Biotreatment on cellulose fluff pulp : quaternary ammonium salts finish and grafting with β -cyclodextrin(2009) Ghemati, Djamila; Aliouche, Djamel; Oudia, Atika; Lamouri, SaadFor its potential performances to be expanded, cellulose needs to be processed in different ways. Therefore, an object of the present work was to provide a chemical modification of cellulose through: a specific finish with two quaternary ammonium salts (namely Aliquat 336 and Aliquat 1529, respectively). Chemical grafting of β -cyclodextrin derivative ( β -CD) onto fibers followed by the inclusion of benzoic acid in the grafted CD cavities as a probe chemical. Physicochemical properties and performances of the untreated and treated fibers have been determined with infrared spectra, microscopy, swelling measurements, antimicrobial finishing tests, and dye adsorption. Our results show that cellulose fibers can be efficiently modified with no significant changes in its structural and surface properties; the treated fibers show an attractive behavior in swelling, dye adsorption and antibacterial activity