Publications Internationales
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Item Impact of π-Extended Auxiliary Acceptors on the Photovoltaic Performance of Dithienosilole-Based Sensitizers. A DFT/TDDFT Investigation(Springer, 2025) Kheffache, Djaffar; Goudjil, Manal; Guemmour, Hind; Rekis, MaammarA novel series of dithienosilole-based D-A-π-A sensitizers was designed for potential application in organic photovoltaic devices by modifying the auxiliary acceptor in the reference dye B-87. Several π-extended electron-withdrawing acceptors, such as benzobisthiadiazole (BBT), thiadiazolobenzotriazole (TBT), thiadiazoloquinoxaline (TQX), pyrazinoquinoxaline (PQX), naphthothiadiazole (NTD), and naphthotriazole (NTA), were investigated for their impact on photovoltaic performance. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations were employed to analyze optical and photophysical properties, considering key photovoltaic parameters such as light harvesting efficiency (LHE), injection driving force (), free energy of regeneration (), and open circuit voltage (VOC). Additional analyses were conducted on the geometries, electronic structures, and absorption spectra of all dyes adsorbed onto the (TiO2)9 anatase cluster. While π-extended auxiliary acceptors generally lowers the HOMO-LUMO gap and broadens absorption, it also reduces intramolecular charge transfer and increase electron trapping. Notably, BBT, TBT, TQX, PQX, and NTD negatively affect charge transfer, leading to weakened photovoltaic performance, particularly a reduced Voc. The designed dye, featuring the π-extended acceptor naphthotriazole (NTA), demonstrates strong potential for DSSC applications due to its enhanced optoelectronic properties and efficient intramolecular charge transferItem Theoretical investigation of the self-association of antitumor drug imexon(Springer, 2020) Guemmour, Hind; Kheffache, DjaffarThe dimers resulting from self-association of oxo-imino, oxo-amino, and hydroxyl-imino tautomers of imexon, that present two hydrogen bonds, were fully optimized with the density functional methods B3LYP, M06-2X in conjunction with 6-311++G(d,p) basis set. Additionally, second-order Møller-Plesset (MP2) level in combination with 6-311++G(d,p) basis set was employed for comparison purpose. The thermodynamic stability of the self assembled structures in gaseous phase has been obtained according to the analyses of total electronic energies and hydrogen bonding interactions. The bulk water environment has been simulated using the universal solvation model based on solute electron density (SMD). Stability and structure of homochiral and heterochiral imexon dimers resulting from the three imexon tautomers have been carried out to investigate the chiral discrimination. The imexon dimer with heterochiral configuration resulting from self-assembling oxo-amino tautomer is found to be thermodynamically most stable in both gas and aqueous phases. The interaction energies for these self assembled structures were further evaluated with the basis set superposition error corrections. The so-called seven-point interaction energy which includes corrections for BSSE and deformation was calculated. The intermolecular interactions of the selected dimers have been analyzed by calculation of electron density (ρ) and Laplacian (∇2ρ) at the bond critical points (BCPs) using atoms-in-molecule (AIM) theory.Item Sustainable starch-based bioplastics reinforced with carob filler: characterization and biodegradability assessments(Taylor and Francis Ltd., 2024) Guemmour, Hind; Kheffache, Djaffar; Khier, NawalStarch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix.Item Vinyl acetate Semi-Continuous emulsion terpolymerization with butyl acrylate and 2-Ethyl hexyl acrylate monomers(Springer, 2021) Guemmour, Hind; Kheffache, DjaffarIn this article we report preparation, physico-chemical and mechanical characterization of poly (vinyl acetate) (PAVc) fi lms resulting from the copolymerization of vinyl acetate (VAc) with two acrylate monomers, butyl acrylate (BuA) and 2‐ethyl hexyl acrylate (2-EHA) via emulsion polymerization method. Vinyl acetate (VAc) was used as principal monomer and copolymerized with butyl acrylate (BuA) and 2‐ethyl hexyl acrylate (2-EHA) at the feeding ratio of 85/15/0, 85/0/15, 85/5/10, 85/10/5, 85/7.5/7.5 wt % of VAc/BuA/2-EHA using deionised water as dispersion medium. The semi-continuous emulsion polymerization was carried out in the presence of potassium persulfate used as free radical initiator, two emulsifiers, anionic and non-ionic surfactants and hydroxyethyl cellulose (HEC) used as a protective colloidal. The obtained copolymers were further analysed by Brookfi eld viscosimeter, Fourier transform infrared spectroscopy (FTIR/ATR), thermogravimetric analysis (TGA/DTG), scanning electron microscopy (SEM) and mechanical tests. The infl uence of composition on thermal characteristics of the obtained fi lms is describedItem Synthesis, characterization and morphology of new aliphatic-aromatic copolyesters based on trans-1,3- indanediol(Taylor and Francis Online, 2018) Guemmour, Hind; Benaboura, AhmedIn this article we report the study on the synthesis and thermal characterization of a new family of aliphatic/aromatic copolyesters that incorporate pure isomer trans-1,3-indanediol. The aromatic diacid terephthaloyl chloride and aliphatic diols HO–(CH2)n–OH with various methylene lengths have been used as co-monomers. The aliphatic diols employed in this study are 1,3-propanediol, 1,4-butanediol, 1,7-heptanediol and 1,10-decanediol. The relevant properties of the synthesized aliphatic–aromatic copolyesters involve viscosity measurements, IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). The obtained aliphatic-aromatic copolyesters present thermostable nature and semi-crystalline properties.Item Synthesis and characterization of aliphatic-aromatic copolyesters based on Cis-1,3-indanediol(Springer, 2013) Guemmour, Hind; Benaboura, AhmedItem Conformational and NMR analysis on cis 1,3-indanediol(Elsevier, 2011) Guemmour, Hind; Kheffache, Djaffar; Benaboura, AhmedItem Conformational analysis and intramolecular hydrogen bonding of cis-3-aminoindan-1-o l : a quantum chemical study(Springer, 2013) Kheffache, Djaffar; Guemmour, Hind; Dekhira, Azzedine; Benaboura, Ahmed; Ouamerali, Ourida