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![1H-NMR spectra of hydroxyethyl cellulose (HEC) (a), hydroxyethyl cellulose acetate (HECA) (b), HECA-P1 (c), and HECA-P2 (d). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]](profile/Amhamdi-Hassan/publication/236686635/figure/fig1/AS:272814452244497@1442055442453/1H-NMR-spectra-of-hydroxyethyl-cellulose-HEC-a-hydroxyethyl-cellulose-acetate-HECA.png)
1H-NMR spectra of hydroxyethyl cellulose (HEC) (a), hydroxyethyl cellulose acetate (HECA) (b), HECA-P1 (c), and HECA-P2 (d). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
Source publication
Esparto “Stipa tenacissima” cellulose esters derivatives: HECA‐COOC4H8COOC2H5, HECA‐COOC8H16COOC2H5, and HECA‐COOC6H4COOC2H5 were successfully prepared in Tetrahydrofuran (THF)/triethylamine system with a degree of substitution (DS), respectively, DSAD‐Et=0.32, DSSB‐Et=0.22, and DSTRP‐Et=0.50 using hydroxyethyl cellulose acetate (HECA; DSAC=0.50) a...
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Citations
... The typical assignment of 1 H-NMR BCac spectrum in DMSO-d 6 is shown in Fig. 3a. The sharp ring proton signals of the cellulose skeleton (AGU) are shown between the resonances 2.8 and 5.6 ppm, although the AGU protons signals appeared at 3.14, 3.64, 3.77, 4.74 and 5.52 ppm which are ascribed to H 4 , H 2 , H 3,5,6 , and H 1 , respectively (El Idrissi et al. 2013;Song et al. 2017). Moreover, the broad signal recorded at 5.52 ppm belongs to the residual hydroxyl protons linked to the carbons C2 and C3 (-O 2 H and -O 3 H) (Guo et al. 2012). ...
In this paper, the dispersion encapsulation was investigated as new process to elaborate the principal active (PA) loaded biodegradable plastic coacervates, which designs a model of vector system and drug delivery matrix. The Rosemary Essential Oil (REO) (~ 54%w) was wrapped, as PA-model, in Benzyl cellulose acrylate (BCac, DSBnz ~ 1.4 and DSAcr ~ 0.4) coacervates that elaborated in the dispersing aqueous phase as new cellulose derivative. The advantage of this modification is to ensure the transition from hydrophilic to hydrophobic character of the cellulosic shell during the encapsulation process, which leads to encapsulation in one step. Indeed, during the reaction, the dispersive forces, generated by the grafting reaction, disturb the hydrophilic character of the water-soluble cellulose acrylate (Cac0.4). Then, the hydrophobic behavior, acquired by the grafted benzylic entities, increases the BCac-affinity to the organic compounds (oily dispersed phase). Therefore, the migration of the resulting polymer chains to the EO-rich (discontinuous) micellar dispersed phase, to form a biphasic micellar membrane, is strongly suggested. Experimental investigations, such as the relationship between the degree of substitution (DS) and the demixing behavior of the polymer solutions, are in good agreement with the theoretical interpretations basing on the Flory–Huggins thermodynamic theory. The results showed a high DS effect on the physicochemical properties, especially the molar Gibbs free energy of mixing.
... HEC was obtained from the chemical modification of cellulose extracted from the esparto plant from the eastern region of Morocco according to the procedure described previously in El Idrissi et al. (2013). Dimethylformamide (DMF) was obtained from the Fluka Company. ...
... Moreover, a quadruplet situated around 7.08 ppm corresponds to the vinyl proton on α of the imidazolium group nitrogen. The signals of the methylene protons on α of the various hydroxyl groups are located at ~ 3.6 ppm, and those attached to the carbon (C6) of the cellulosic skeleton give signals at around ~ 3.5 ppm (El Idrissi et al. 2013). The signal that appeared at 4.15 ppm corresponds to protons of methylene (-CH 2 -O-C=O) on α of the ester. ...
... Moreover, the methylene group on α of the quaternary nitrogen shows a signal around 4.91 ppm. The characteristic peaks of the HEC-Br backbone appeared around 3.45, 3.6 and 4.2 ppm (El Idrissi et al. 2013). The 13 C NMR spectrum of HEC-MI (Fig. 3d) shows the appearance of new peaks around 123-137 and 36.15 ...
Hydroxyethyl cellulose (HEC) is considered one of the most important hydro-soluble cellulose derivatives, thanks to its biocompatibility and biodegradability profile. In this work, a facile synthesis methodology was developed to graft ionic liquids onto the HEC ester. Firstly, a low Tg (glass transition temperature) glassy brominated hydrophobic ester based on HEC was prepared. By regioselective nucleophilic substitution of bromine with imidazole and pyridine derivatives, HEC-ILs (ionic liquids) with a high degree of substitution were elaborated in a second step. The synthesized HEC-ILs were characterized by nuclear magnetic resonance (¹H, ¹³C NMR), elemental analysis (CHNO), Fourier transform infrared spectroscopy-Attenuated total reflection (FTIR-ATR), X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. Zeta potential was used to verify the presence of permanent positive charge. Contact angle measurements were exploited to follow the reorganization of the surface of HEC-ILs in contact with water. A theoretical study was carried out to investigate the intra- and intermolecular interactions of polymer chains. The prepared cationic HEC derivatives have attractive properties such as their amphiphilic and glassy character, solubility in water, and a permanent positive charge. Such properties open a wide range of applications in the field of drug delivery and the complexation of anionic molecules.
Graphical Abstract
... Selulosa juga dikenal sebagai material yang memiliki ketahanan termal yang baik, sehingga keunggulan ini sangat diperlukan. Beberapa penelitian telah berhasil memanfaatkan selulosa dalam bentuk nanoselulosa maupun selulosa termodifikasi/terfungsionalisasi sebagai agen penguat (filler) pada matriks material polimer lainnya maupun dimanfaatkan sebagai bahan pendukung industri farmasi maupun makanan (Zhang, et al., 2013;Mai & Koo, 2016;Idrissi, Barkany, Amhamdi, & Maaroufi, 2013). ...
... The spectrum showed the absorption bands around 1406 cm − 1 which was attributed to the -CH 2 bending [57]. The bands around 1335 and 1260 cm − 1 were allotted to the vibrations of C -C and C -O characteristics of the cellulose skeleton [58]. The absorption band at 1157 cm − 1 is related to C-O anti-symmetric bridge stretching. ...
... The absorption band at 1157 cm − 1 is related to C-O anti-symmetric bridge stretching. The band at 895 cm − 1 was derived from b-glucosidic linkages between glucose units in cellulose [58]. ...
The terrible rise of antibiotic residues which possesses a serious threat to the ecological and aquatic environments. So, the development of highly cost-effective, highly operation-convenient and recyclable adsorbents was a must. In our study, we utilized the ternary layered double hydroxide (CoZnAl LDH) as an efficient adsorbent and nano-carrier for Clarithromycin (CLA) residues for their biodegradability and biocompatibility. Also, we enhanced the removal efficiency of the synthesized ternary LDH using cellulose-based activated carbon which was obtained using the hydrothermal carbonization method followed by chemical activation via static air converting the cellulose derivative (hydroxy ethyl cellulose HEC) into highly porous activated carbon that played an important role in the adsorption process. Full characterization of the synthesized activated carbon (AC) and the adsorbents before and after the adsorption processes were carried out using different techniques. The differences between the two adsorbents were investigated in a comparative study in terms of factors affecting the adsorption process like pH, the dose of adsorbent, time, and temperature. The adsorption isotherm was investigated at pH 10 with high regression coefficient (R²) of 0.99 showing maximum adsorption capacity (qmax) of 61.5 mg/g for (CLA) using LDH as adsorbent, whereas, the investigation using the modified LDH (LDH-AC) with high regression coefficient (R²) of 0.99 shows maximum adsorption capacity (qmax) of 495 mg/g for (CLA). Kinetic studies were estimated. The thermodynamic parameters such as ΔS°, ΔG° and ΔH° were estimated showing that the adsorption processes undergo exothermic and spontaneous routes.
The safety and cytotoxicity of the modified, synthesized LDH (LDH-AC) were investigated besides the investigation of the gastroprotective efficacy against generated stomach ulcers. (LDH-AC) showed significant reduction for the generated ulcer in addition to the enhancement of the gastro protective efficacy revealing the safe use of LDH-AC/CLA for biological purposes like ulcer reduction and the enhancement of the ulcer inhibition.
... Pelarut terbitan merujuk kepada pelarutan selulosa yang berlaku dengan terbentuknya kumpulan terbitan seperti eter, ester dan asetal yang tidak stabil hasil daripada ubah suai secara kimia ke atas struktur selulosa asli (El Idrissi et al. 2013;Heinze & Koschella 2005). Hasil daripada kemajuan dalam bidang sains dan teknologi selulosa, fungsi, sifat dan kebolehan selulosa asli atau selulosa I kini boleh dipertingkatkan dengan membentuk struktur baharu yang dikenali sebagai selulosa terbitan dengan aplikasinya lebih meluas sebagai agen pemekat dan sistem perlepasan terkawal. ...
Filem selulosa terjana semula (FSTS) merupakan produk yang dijana semula daripada selulosa terlarut secara interaksi fizikal mahupun kimia. Sifat fizikal, mekanikal dan kimia FSTS bergantung kepada jenis pelarut yang digunakan terhadap selulosa, agen penggumpalan, teknik penuangan serta kaedah pengeringan. Pembentukan FSTS sangat bergantung kepada keterlarutan selulosa serta proses penjanaan semulanya. Oleh itu, mekanisma pembubaran di dalam pelarut terbitan dan tak-terbitan yang terpilih serta agen penggumpal seperti air, campuran air dan aseton, asid sulfurik, medium berasaskan sulfat seperti ammonium sulfat dan gabungan di antara dua kumpulan alkohol dan dua kumpulan ester akan ditekankan dalam ulasan kajian ini. Selain itu, kecenderungan aplikasi FSTS yang terhasil berdasarkan pelarut dan agen penggumpal yang berbeza juga diulas.
... In addition, the absorption bands at 1457 cm -1 and 1075 cm -1 approved the deformations in the O-H plane of the primary alcohol and the vibrations of the C-O-C polysaccharide skeleton, respectively (Azzaoui et al., 2015). The band at 880 cm -1 is a characteristic of the osidic β carbohydrate linkages (El Idrissi, El Barkany, Amhamdi, & Maaroufi, 2013). ...
In this paper, a new deep eutectic solvent (DES) has been successfully synthesized that is based on benzyltriethylammonium
bromide as a hydrogen bond acceptor (HBA) and urea as a hydrogen bond donor (HBD).
However, its usability in modifying cellulose derivatives, especially acylating hydroxyethylcellulose (HEC) was
investigated. The chemical modification (acetylation) of HEC was carried out in BTEAB/urea DES system without
any additional conventional solvent or catalyst. However, the proposed structure of acetylated HEC (HECA) was
confirmed according to the structural spectra analyses FTIR-ATR, 1H, 13C, and APT-NMR. The crystalline
behavior of acetylated and unmodified HEC in the DES system has been evaluated using XRD patterns, where the
thermal stability was evaluated basing on the TD-TGA thermograms. Hence, SEM images and EDX spectra were
recorded to prove the changes that are expected at the morphological level and elemental profile. Yet, the
nanometric sheets aspect was observed. The Functional Density Theory (DFT) was investigated as a useful
computational tool to understand mechanism and donor-acceptor interactions. The topological parameters
(electron density Laplacian, kinetic energy density, potential energy density, and energy density) at the bond
critical points (BCP), between TBEAB and urea, are deducted according to Quantum Bader's theory, and Atomsin-
molecules (AIM). The non-covalent interactions and steric effect in the DES system were studied using the
reduced density gradient isosurface (RDG). Theoretical and computational calculations revealed that the Hbonds
and the electrostatic coexist, as predominant interactions in the BTEAB-based DES resulting chemical
structure, and mechanism formation. The physical interactions between the component entities of DES lead to a
new equilibrium that is more stable than that of HBA and HBD in their separate states.
... In addition, the absorption bands at 1457 cm − 1 and 1075 cm − 1 approved the deformations in the O -H plane of the primary alcohol and the vibrations of the C-O-C polysaccharide skeleton, respectively (Azzaoui et al., 2015). The band at 880 cm − 1 is a characteristic of the osidic β carbohydrate linkages (El Idrissi, El Barkany, Amhamdi, & Maaroufi, 2013). ...
In this paper, a new deep eutectic solvent (DES) has been successfully synthesized that is based on benzyltriethylammonium bromide as a hydrogen bond acceptor (HBA) and urea as a hydrogen bond donor (HBD). However, its usability in modifying cellulose derivatives, especially acylating hydroxyethylcellulose (HEC) was investigated. The chemical modification (acetylation) of HEC was carried out in BTEAB/urea DES system without any additional conventional solvent or catalyst. However, the proposed structure of acetylated HEC (HECA) was confirmed according to the structural spectra analyses FTIR-ATR, ¹H, ¹³C, and APT-NMR. The crystalline behavior of acetylated and unmodified HEC in the DES system has been evaluated using XRD patterns, where the thermal stability was evaluated basing on the TD-TGA thermograms. Hence, SEM images and EDX spectra were recorded to prove the changes that are expected at the morphological level and elemental profile. Yet, the nanometric sheets aspect was observed. The Functional Density Theory (DFT) was investigated as a useful computational tool to understand mechanism and donor-acceptor interactions. The topological parameters (electron density Laplacian, kinetic energy density, potential energy density, and energy density) at the bond critical points (BCP), between TBEAB and urea, are deducted according to Quantum Bader's theory, and Atoms-in-molecules (AIM). The non-covalent interactions and steric effect in the DES system were studied using the reduced density gradient isosurface (RDG). Theoretical and computational calculations revealed that the H-bonds and the electrostatic coexist, as predominant interactions in the BTEAB-based DES resulting chemical structure, and mechanism formation. The physical interactions between the component entities of DES lead to a new equilibrium that is more stable than that of HBA and HBD in their separate states.
... This decreasing indicates that the content of the amorphous regions increases significantly, allowing their modification and transformation to occur easily. 60 In addition, this fact indicates that these products have lost their crystallinity after fiber modification. For CA and fluorinated CA carbamates, a small variation in the crystallinity index between CA (63.98%), ...
Cellulose (Cell) and cellulose acetate (CA) are attractive durable materials; they can acquire various properties through modification in order to obtain valuable industrial products. First, a series of novel fluorinated cellulose carbamate and fluorinated CA carbamate have been synthesized. The introduction of fluoro-groups onto cellulose and CA chain backbone was achieved by the one-pot grafting method using diisocyanate as a coupling agent, which can be considered as a green procedure. The compounds prepared were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) measurements. The results obtained from these analytical techniques confirm that modification occurs successfully. Second, the solubility behavior and biodegradation process of these new fluorinated materials have been studied. The results show that these new materials exhibit better solubility compared to cellulose, but this solubility decreases compared to that of CA. The phenomenon of biodegradation was studied using two methods, the rate of biodegradability was determined. The results of this part show that the biodegradation of fluorinated materials decreases compared to that of the starting materials. These novel materials are biodegradable, can substitute currently used industrial non-biodegradable products and be promising agents for several uses, such as bioplastics, drug carriers, etc. A sustainable development and an increased use of green chemistry principles are among the essential objectives of this work.
... and 4b, the loss of weight during the TG analysis of HEC can be divided into three steps. The initial weight loss (~17% for HEC) by heating the materials up to 150 °C owing to the moisture elimination with decomposition temperature (T d ) of 74 °C for to the thermal cleavage of the glucosidic units and scission of the C-O bonds[39]. The third step starts at 450 °C and represents the carbonization of the products to ash. ...
The present investigation deals with the elaboration in homogenous conditions of new cross-linked, hydroxyl cellulose (HEC) based material. Further, its application as a new eco-friendly low-cost efficient adsorbent of hazardous metal ions from an aquatic environment is treated. In this respect, the functionalization of HEC has been carried out using EDTA as a cross-linking agent exploiting its high capacity to chelate heavy metal ions in aqueous solutions. The proposed structure of the new crosslinked material (HECD) was investigated using structural analyses (FTIR-ATR vibrational spectroscopy and CP/MAS 13C NMR Spectroscopy). Also, the thermal and crystalline behaviours of unmodified and modified HEC were studied using thermogravimetric (TG and DTG) and DRX patterns. In addition, SEM images were recorded to demonstrate the changes expected at the morphological and textural level. Furthermore, the adsorption capacity of Pb (II), Cu (II), Cd (II) and Zn (II) ions from aqueous solutions by HECD was investigated using batch technique and optimized according to metal concentration, pH, contact time, ionic selectivity and regenerability. Thus, to examine the mechanism of adsorption, the experimental data is fitted to kinetic, isothermal, and thermodynamic modelling.
... The CrI decreased from 88% to 85% for cellulose and its Cell-HDI-thiol derivative, indicating that the content of the amorphous regions has not changed so much. 49 In addition, this fact indicates that the product does not lose its crystallinity after this modification type. For cellulose acetate and CA-HDI-thiol, respectively, an increase in the crystallinity index was noted, varying from 64% to 84%. ...
