Othman Hamed - Academia.edu (original) (raw)

Papers by Othman Hamed

Polymers

In this work, we present a process for converting olive industry solid waste (OISW) into a value-... more In this work, we present a process for converting olive industry solid waste (OISW) into a value-added material with ionic receptors for use in the removal of toxic metal ions from wastewater. This 3D polymer is a promising adsorbent for large-scale application, since it is a low-cost material made from agricultural waste and showed exceptional performance. The synthesis of the network polymer involved the carboxymethylation of OISW and curing of the carboxymethylated OISW at an elevated temperature to promote the formation of ester linkages between OISW’s components. FT-IR, atomic force microscopy, and thermal analysis were performed on the crosslinked product. The adsorption efficiency of the crosslinked carboxymethylated OISW toward Pb(II), Cu(II), and other toxic metal ions present in sewage was evaluated as a function of adsorbent dose, temperature, pH, time, and initial metal ion. The percentage removal of about 20 metal ions present in a sewage sample collected from a sewer p...

Indonesian Journal of Science and Technology

Amorphous iron phosphate, FePO4.2H2O, was synthesized at ambient temperature using an inorganic s... more Amorphous iron phosphate, FePO4.2H2O, was synthesized at ambient temperature using an inorganic sol-gel method coupled with a microwave route. The experimental conditions for the gelling of the Fe (III)-H3PO4 system are defined. Potentiometric Time Titration (PTT) and Potentiometric Mass Titration (PMT) methods were used to investigate the acid-base surface chemistry of obtained phosphate. Variations of surface charge with the contact time, Q = f(t), are examined for time contact ranged from 0 to 72 hours. The concentrations suspensions used for this purpose were 0.75, 1.25, and 2.5 g/L. The point of zero charges (PZC) and isoelectric point (IEP) were defined using the derivative method examining the variations , at lower contact time. A value of 5.4 was obtained for both PZC and IEP. Q in the function of the t method is performed for synthesized FePO4. 2H2O in NaCl and KCl electrolytes. The optimal surface charge of 40 C corresponding to insertion of 4.2x10-4 M of Na+ or K+, is ac...

Frontiers in Chemistry

The expanding amount of remaining drug substances in wastewater adversely affects both the climat... more The expanding amount of remaining drug substances in wastewater adversely affects both the climate and human well-being. In the current investigation, we developed new cellulose acetic acid derivation/zeolite fiber as an effective technique to eliminate erythromycin (ERY) from wastewater. The number of interchangeable sites in the adsorbent structures and the ratio of ERY to the three adsorbents were identified as the main reasons for the reduction in adsorption as the initial ERY concentrations increased. Additionally, for all adsorbents, the pseudo–second-order modeling showed better fitting for the adsorption than the pseudo–first-order modeling. However, the findings obtained in the pseudo–first-order model were still enough for explaining the sorption kinetics of ERY, showing that the surface displayed all chemisorption and physi-sorption adsorption processes by both adsorbents. TheR2for the second order was very close to 1 for the three adsorbents in the case of pseudo–second-...

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Aug 1, 2018

Olive industry solid waste (OISW) is a by-product generated in the process of olive oil extractio... more Olive industry solid waste (OISW) is a by-product generated in the process of olive oil extraction. It is a lignocellulosic material consisting of cellulose, hemicelluloses, lignin and other extractives. In this work, a process for hydrolyzing the OISW into its monomers glucose, the precursor of bioethanol was developed. The hydrolysis process involves two stages: in the first stage the OISW was activated by treating it with a material that opened the cellulose structure and made it more accessible for chemical reagents. Several activating materials were evaluated among them are water, NaOH, Ca(OH)₂ and acetic acid. In the second stage, the OISW was subjected to an enzymatic treatment which hydrolyzed it into sugar. A combination of the two enzymes cellulase (endo-1,4-β-glucanase) and β-glucosidase was used in the hydrolysis. Best hydrolysis results were obtained at enzymes dose of 15.0 mg of cellulase and 20.0 mg/g of β-glucosidase per one gram of OISW at 45 o C and a pH of 4.8. A yield of 85.02% sugar was obtained from the hydrolysis of 10% NaOH pre-treated OISW under a positive pressure of air. Whereas, hydrolysis of cellulose extracted from OISW by the Kraft pulping process and bleached using DEHP beaching sequence produced about 95.30% sugar.

Volume 5, Issue 9, September 2016 Page 249 ABSTRACT The springs of water in the bed of Oued Essaq... more Volume 5, Issue 9, September 2016 Page 249 ABSTRACT The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illustrate impacts of entropic activities on the physico-chemical quality of these waters of springs. The analysis of the situation concerning spring, shows a rather important potential in quantity of water.However, the physico-chemical quality of the water is very low, characterized by very high mineralization and constituents at this state a source of degradation of the immediate environment, furthermore the results of the physicochemical parameters indicators of pollution : COD (chemical oxygen demand), BOD5 (biochemical oxygen demand over 5 days), dissolved oxygen (DO), nitrate (NO3), nitrite (NO2), ammonium (NH4), Kjeldahl nitrogen NTK, phosphates (total PT and orthophosphate PO4), etc. stipulate that the waters in thesesources are exposed to heavy pollution expressed by those parameters that exceed standards. In the absence of polluti...

Praise and thanks to Almighty Allah , the most merciful for assisting and directing me to the rig... more Praise and thanks to Almighty Allah , the most merciful for assisting and directing me to the right path, without his help my effort would have gone astray. It would have been impossible to make this thesis without the help and support of several persons: First of all I would like to express my sincere gratitude to my supervisors Dr. Othman Hamed and Dr. Shehdeh Jodeh for their excellent guidance throughout this work and they gave me always time for discussions, full of encouragement and patience. I would like to thank, Mr. Maher Kharoof the director of Quality Control Manager in Jerusalem pharmaceuticals Co.Ltd, who was always concerned about my project and his support was very reviving. I really appreciate and thank Dr. Mohammed Al-Nuri for his consistent help me and support during my research. Finally, many thank to Mr .Omair Nabulsi, and Nafez Dweekat and Mohammad Asa'ad and Khaled Abu Nasser and Najwah Sobuh for their help during this work.

Accounts of Chemical Research, 1973

Developing a new effective anticancer agent becomes an urgent need to overcome of current drug-re... more Developing a new effective anticancer agent becomes an urgent need to overcome of current drug-resistance. In this study we demonstrated that curcumin with heterocyclic moiety can function as an anticancer agent in a human. A new series of curcumin-based benzodiazepines, diazepines and diazoles were prepared using a simple one pot process. The process involved a condensation reaction of curcumin with various 1,2 diamino compounds and hydrazine. The structures of the prepared heterocycles were identified by the spectroscopic methods FT-IR, 1H NMR, and 13C NMR. The in vitro anticancer activities of the synthesized curcumin-based heterocycles against HeLa cancer cells were evaluated by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of HeLa cells was reduced in the range of 4.48- 14.57% within the studied concentrations. Curcumin-based diazepine 6 showed the highest cytotoxic effect on the HeLa cells at all concentrations. it reduced the via...

BMC Chemistry

Background Cellulose polymers with multidentate chelating functionalities that have high efficien... more Background Cellulose polymers with multidentate chelating functionalities that have high efficiency for toxic metal ions present in water were designed, synthesized, and analyzed. The synthesis was carried out by reacting microcrystalline cellulose extracted from the solid waste of the olive industry with tert-Butyl acetoacetate (Cell-AA), produced cellulose with β-ketoester functionality was then reacted with aniline and the amino acid glycine to produce Cell-β-AN and Cell-β-GL, respectively. Results The adsorption efficiency of the three polymers toward Pb(II) and various toxic metal ions present in sewage was evaluated as a function of adsorbent dose, time, temperature, pH value, and initial ion concentration to determine optimum adsorption conditions. The three polymers showed excellent efficiency toward about 20 metal ions present in a sewage sample collected from the sewer. The adsorption process follows the Langmuir adsorption isotherm model with a second-order of adsorption ...

Tetrahedron Letters, 2010

Pd-catalyzed olefin dicarbonylation of chiral allylic alcohols with chirality transfer affords th... more Pd-catalyzed olefin dicarbonylation of chiral allylic alcohols with chirality transfer affords the chiral alcohol diesters contiguous chiral centers, in good to excellent diastereoselectivities (78-98%). HO CO (3 atm), PdCl 2 NaOAc, HC(OMe) 3 MeOH, rt, 72h HO CO 2 Me CO 2 Me

A combined electrochemical and theoretical study into the effect of curcumin as a corrosion inhib... more A combined electrochemical and theoretical study into the effect of curcumin as a corrosion inhibitor for mild steel in 1 M HCl.

This proposal is divided into two Parts: I. Exchange and oxidation of chiral allylic alcohols usi... more This proposal is divided into two Parts: I. Exchange and oxidation of chiral allylic alcohols using chirality transfer. II. Asymmetric synthesis using Pd(Il) catalysts with chiral auxiliaries. Part I is divided into two sections: A. The determination of stereochemistries of hydroxypalladation using chirality transfer. B. Preparation of trichiral molecules. The allylic alcohols used for these studies included (R)-(-)-Zand £-3-hexen-2-ol (13a), (R)-(-)-Z-4hexen-3-ol (13b), (R)-Zand £-3-penten-2-ol (17). The chiral alcohols were prepared by reduction of the corresponding alkynones with alpine-borane reagent to give the alkynones which were reduced with either Lindlar's catalyst or Li~ to give the Z and E isomers respectively. At low [Cr] PdCLt oxidizes 13a to a mixture of (R)-Z-4-hydroxy-2-hexanone (15a) and (R)-5-hydroxy-3-hexanone (15b ). The configuration of 15a was consistent with syn hydroxypalladation. At high [Cr] (>2 M) PdCl/isomerizes 13b to (S)-Z-13a. This result is mo...

The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illu... more The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illustrate impacts of entropic activities on the physico-chemical quality of these waters of springs. The analysis of the situation concerning spring, shows a rather important potential in quantity of water.However, the physico-chemical quality of the water is very low, characterized by very high mineralization and constituents at this state a source of degradation of the immediate environment, furthermore the results of the physicochemical parameters indicators of pollution : COD (chemical oxygen demand), BOD5 (biochemical oxygen demand over 5 days), dissolved oxygen (DO), nitrate (NO3), nitrite (NO2), ammonium (NH4 +), Kjeldahl nitrogen NTK, phosphates (total PT and orthophosphate PO4 2-), etc. stipulate that the waters in thesesources are exposed to heavy pollution expressed by those parameters that exceed standards. In the absence of polluting industry in the city of Laayoune; it appears...

The goal of this work was to develop polymer-based heterocycle for water purification from toxic ... more The goal of this work was to develop polymer-based heterocycle for water purification from toxic pesticides such as difenoconazole. The polymer chosen for this purpose was cellulose nanocrystalline (CNC); two cellulose based heterocycles were prepared by crosslinking with 2,6-pyridine dicarbonyl dichloride (Cell-X), and derivatizing with 2-furan carbonyl chloride (Cell-D). The synthesized cellulose-based heterocycles were characterized by SEM, proton NMR, TGA and FT-IR spectroscopy. To optimize adsorption conditions, the effect of various variable such as time, adsorbent dose, pH, temperature, and difenoconazole initial concentration were evaluated. Results showed that, the maximum difenoconazole removal percentage was about 94.7%, and 96.6% for Cell-X and Cell-D, respectively. Kinetic and thermodynamic studies on the adsorption process showed that the adsorption of difenoconazole by the two polymers is a pseudo-second order and follows the Langmuir isotherm model. The obtained valu...

Many thanks to whom our thanks go as well to them for their follow up the project. I would like t... more Many thanks to whom our thanks go as well to them for their follow up the project. I would like to thank all the technicians and staff of the chemistry department at An-Najah National University, especially Mr. Omair Al-Nabulsi and Mr. Nafiz Dweikat for their help. I would like also to express my thanks to all friends in the master program for the great and lovely time that we spent together. Last but not the least, I would like to thank my family: my parents Alham and Mohammed Melhem, for giving birth to me at the first place and supporting me spiritually and financially throughout my life. v ‫ار‬ ‫اإلقر‬ ‫تحمل‬ ‫التي‬ ‫الرسالة‬ ‫مقدم‬ ‫أدناه‬ ‫الموقع‬ ‫أنا‬ ‫ان‬ ‫العنو‬ : Synthesis and characterization of magnetic nano cellulose from olive waste (Jeft) for the effective removal of methylene blue from aquous solution

Film directing toward applications in food packaging and counter top coating with ability of inhi... more Film directing toward applications in food packaging and counter top coating with ability of inhibiting antimicrobial growth is important for maintaining food freshness and reducing bacteria transmittance. In this work, cellulose-based fatty amine with antimicrobial functionality covalently attached to cellulose backbone was synthesized. The synthesis was performed in a three-step process that involves cellulose oxidation, amination of oxidized cellulose using fatty amine and reduction. Films composites with various proportions of cellulose-based amine and cellulose triacetate were prepared. The films morphologies, tensile strengths, percent of elongation and contact angle were evaluated. The cellulose-based amine showed excellent antimicrobial activity against gram positive and moderate activity toward gram-negative bacteria. The films prevented the growth of gram-positive bacteria by 99.99%. Results indicate a good mechanical properties and bioactivities of produced film which mak...

Olive Industry Solid Waste is the remaining part of the grain of the olive industry after squeezi... more Olive Industry Solid Waste is the remaining part of the grain of the olive industry after squeezing it, it consists of wood seeds and pulp. The OISW consists of cellulose, hemicelluloses, lignin and extractives. In this work, cellulose the most valuable ingredient of OISW, was extracted in a multistep process. The process begins with pre-hydrolysis stage which opens the OISW structure and makes it more accessible for chemicals. Also in this stage, most of the hemicelluloses materials present in OISW are degraded and dissolve in water. In the prehydrolysis stage, different materials were evaluated and satisfactory results were obtained using water alone. Then OISW was subjected to the pulping process using an aqueous solution of sodium sulfide and sodium hydroxide. In the pulping stage most of the lignin is degraded and removed. The produced pulp was then subjected to a bleaching process to remove residual colored materials. Excellent results were obtained using the bleaching sequenc...

Hydroxypropyl methylcellulose in an aqueous solution upon heating tends to undergo thermal gelati... more Hydroxypropyl methylcellulose in an aqueous solution upon heating tends to undergo thermal gelation, where the polymer chains form a network and precipitate from solution. This occurs at a temperature known as thermal gelation point. Polymer precipitation causes a significant drop in the shear viscosity. This could be a disadvantage in a hot environment or in applications were heat is applied. In this work, a hydroxypropylmethyl cellulose (HPMC) was formed that undergoes thermal gelation with no polymer precipitation and with enhanced rheological properties. The target HPMC was prepared from wood pulp with a low content of carboxymethyl groups. The produced hydroxypropyl methylcellulose (CMHPMC) derivative showed unique physical properties that are not achievable with typical hydroxypropyl methylcellulose. The thermal gelation temperature of an aqueous solution of CMHPMC was increased from 55 °C for commercial HPMC to 85 °C for CMHPMC. A substitution level of carboxymethylation that...

Several new epoxy monomers were synthesized from glycidylation of functional aromatic amines cont... more Several new epoxy monomers were synthesized from glycidylation of functional aromatic amines containing hydroxyl or thiol groups. The epoxy monomers were triglycidyl-2-aminophenol, triglycidyl-2-aminothiophenol, tetraglycidyl-1,2-phenylenediamine and tetraglycidyl-4-methyl-1,2-phenylenediamine. The characterization of the epoxy monomers was carried out by FTIR and 1H NMR spectroscopy. Rheological properties of solutions of the epoxy monomers in ethanol were evaluated using an advanced rheometer. The effect of solution concentration and temperature on the viscosity of the epoxy solution was evaluated. The shear rheology study at various temperatures of the epoxy resins solutions in ethanol was carried out on solutions with concentrations ranges form 0.5 to 5 wt% and temperatures (20–70 °C). The results revealed that the tetra-functional epoxy resins behave as Newtonian liquids and its viscosity is independent on the shear rate. However, the solutions of tri-functional epoxy resins ar...

Polymers

In this work, we present a process for converting olive industry solid waste (OISW) into a value-... more In this work, we present a process for converting olive industry solid waste (OISW) into a value-added material with ionic receptors for use in the removal of toxic metal ions from wastewater. This 3D polymer is a promising adsorbent for large-scale application, since it is a low-cost material made from agricultural waste and showed exceptional performance. The synthesis of the network polymer involved the carboxymethylation of OISW and curing of the carboxymethylated OISW at an elevated temperature to promote the formation of ester linkages between OISW’s components. FT-IR, atomic force microscopy, and thermal analysis were performed on the crosslinked product. The adsorption efficiency of the crosslinked carboxymethylated OISW toward Pb(II), Cu(II), and other toxic metal ions present in sewage was evaluated as a function of adsorbent dose, temperature, pH, time, and initial metal ion. The percentage removal of about 20 metal ions present in a sewage sample collected from a sewer p...

Indonesian Journal of Science and Technology

Amorphous iron phosphate, FePO4.2H2O, was synthesized at ambient temperature using an inorganic s... more Amorphous iron phosphate, FePO4.2H2O, was synthesized at ambient temperature using an inorganic sol-gel method coupled with a microwave route. The experimental conditions for the gelling of the Fe (III)-H3PO4 system are defined. Potentiometric Time Titration (PTT) and Potentiometric Mass Titration (PMT) methods were used to investigate the acid-base surface chemistry of obtained phosphate. Variations of surface charge with the contact time, Q = f(t), are examined for time contact ranged from 0 to 72 hours. The concentrations suspensions used for this purpose were 0.75, 1.25, and 2.5 g/L. The point of zero charges (PZC) and isoelectric point (IEP) were defined using the derivative method examining the variations , at lower contact time. A value of 5.4 was obtained for both PZC and IEP. Q in the function of the t method is performed for synthesized FePO4. 2H2O in NaCl and KCl electrolytes. The optimal surface charge of 40 C corresponding to insertion of 4.2x10-4 M of Na+ or K+, is ac...

Frontiers in Chemistry

The expanding amount of remaining drug substances in wastewater adversely affects both the climat... more The expanding amount of remaining drug substances in wastewater adversely affects both the climate and human well-being. In the current investigation, we developed new cellulose acetic acid derivation/zeolite fiber as an effective technique to eliminate erythromycin (ERY) from wastewater. The number of interchangeable sites in the adsorbent structures and the ratio of ERY to the three adsorbents were identified as the main reasons for the reduction in adsorption as the initial ERY concentrations increased. Additionally, for all adsorbents, the pseudo–second-order modeling showed better fitting for the adsorption than the pseudo–first-order modeling. However, the findings obtained in the pseudo–first-order model were still enough for explaining the sorption kinetics of ERY, showing that the surface displayed all chemisorption and physi-sorption adsorption processes by both adsorbents. TheR2for the second order was very close to 1 for the three adsorbents in the case of pseudo–second-...

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Aug 1, 2018

Olive industry solid waste (OISW) is a by-product generated in the process of olive oil extractio... more Olive industry solid waste (OISW) is a by-product generated in the process of olive oil extraction. It is a lignocellulosic material consisting of cellulose, hemicelluloses, lignin and other extractives. In this work, a process for hydrolyzing the OISW into its monomers glucose, the precursor of bioethanol was developed. The hydrolysis process involves two stages: in the first stage the OISW was activated by treating it with a material that opened the cellulose structure and made it more accessible for chemical reagents. Several activating materials were evaluated among them are water, NaOH, Ca(OH)₂ and acetic acid. In the second stage, the OISW was subjected to an enzymatic treatment which hydrolyzed it into sugar. A combination of the two enzymes cellulase (endo-1,4-β-glucanase) and β-glucosidase was used in the hydrolysis. Best hydrolysis results were obtained at enzymes dose of 15.0 mg of cellulase and 20.0 mg/g of β-glucosidase per one gram of OISW at 45 o C and a pH of 4.8. A yield of 85.02% sugar was obtained from the hydrolysis of 10% NaOH pre-treated OISW under a positive pressure of air. Whereas, hydrolysis of cellulose extracted from OISW by the Kraft pulping process and bleached using DEHP beaching sequence produced about 95.30% sugar.

Volume 5, Issue 9, September 2016 Page 249 ABSTRACT The springs of water in the bed of Oued Essaq... more Volume 5, Issue 9, September 2016 Page 249 ABSTRACT The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illustrate impacts of entropic activities on the physico-chemical quality of these waters of springs. The analysis of the situation concerning spring, shows a rather important potential in quantity of water.However, the physico-chemical quality of the water is very low, characterized by very high mineralization and constituents at this state a source of degradation of the immediate environment, furthermore the results of the physicochemical parameters indicators of pollution : COD (chemical oxygen demand), BOD5 (biochemical oxygen demand over 5 days), dissolved oxygen (DO), nitrate (NO3), nitrite (NO2), ammonium (NH4), Kjeldahl nitrogen NTK, phosphates (total PT and orthophosphate PO4), etc. stipulate that the waters in thesesources are exposed to heavy pollution expressed by those parameters that exceed standards. In the absence of polluti...

Praise and thanks to Almighty Allah , the most merciful for assisting and directing me to the rig... more Praise and thanks to Almighty Allah , the most merciful for assisting and directing me to the right path, without his help my effort would have gone astray. It would have been impossible to make this thesis without the help and support of several persons: First of all I would like to express my sincere gratitude to my supervisors Dr. Othman Hamed and Dr. Shehdeh Jodeh for their excellent guidance throughout this work and they gave me always time for discussions, full of encouragement and patience. I would like to thank, Mr. Maher Kharoof the director of Quality Control Manager in Jerusalem pharmaceuticals Co.Ltd, who was always concerned about my project and his support was very reviving. I really appreciate and thank Dr. Mohammed Al-Nuri for his consistent help me and support during my research. Finally, many thank to Mr .Omair Nabulsi, and Nafez Dweekat and Mohammad Asa'ad and Khaled Abu Nasser and Najwah Sobuh for their help during this work.

Accounts of Chemical Research, 1973

Developing a new effective anticancer agent becomes an urgent need to overcome of current drug-re... more Developing a new effective anticancer agent becomes an urgent need to overcome of current drug-resistance. In this study we demonstrated that curcumin with heterocyclic moiety can function as an anticancer agent in a human. A new series of curcumin-based benzodiazepines, diazepines and diazoles were prepared using a simple one pot process. The process involved a condensation reaction of curcumin with various 1,2 diamino compounds and hydrazine. The structures of the prepared heterocycles were identified by the spectroscopic methods FT-IR, 1H NMR, and 13C NMR. The in vitro anticancer activities of the synthesized curcumin-based heterocycles against HeLa cancer cells were evaluated by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of HeLa cells was reduced in the range of 4.48- 14.57% within the studied concentrations. Curcumin-based diazepine 6 showed the highest cytotoxic effect on the HeLa cells at all concentrations. it reduced the via...

BMC Chemistry

Background Cellulose polymers with multidentate chelating functionalities that have high efficien... more Background Cellulose polymers with multidentate chelating functionalities that have high efficiency for toxic metal ions present in water were designed, synthesized, and analyzed. The synthesis was carried out by reacting microcrystalline cellulose extracted from the solid waste of the olive industry with tert-Butyl acetoacetate (Cell-AA), produced cellulose with β-ketoester functionality was then reacted with aniline and the amino acid glycine to produce Cell-β-AN and Cell-β-GL, respectively. Results The adsorption efficiency of the three polymers toward Pb(II) and various toxic metal ions present in sewage was evaluated as a function of adsorbent dose, time, temperature, pH value, and initial ion concentration to determine optimum adsorption conditions. The three polymers showed excellent efficiency toward about 20 metal ions present in a sewage sample collected from the sewer. The adsorption process follows the Langmuir adsorption isotherm model with a second-order of adsorption ...

Tetrahedron Letters, 2010

Pd-catalyzed olefin dicarbonylation of chiral allylic alcohols with chirality transfer affords th... more Pd-catalyzed olefin dicarbonylation of chiral allylic alcohols with chirality transfer affords the chiral alcohol diesters contiguous chiral centers, in good to excellent diastereoselectivities (78-98%). HO CO (3 atm), PdCl 2 NaOAc, HC(OMe) 3 MeOH, rt, 72h HO CO 2 Me CO 2 Me

A combined electrochemical and theoretical study into the effect of curcumin as a corrosion inhib... more A combined electrochemical and theoretical study into the effect of curcumin as a corrosion inhibitor for mild steel in 1 M HCl.

This proposal is divided into two Parts: I. Exchange and oxidation of chiral allylic alcohols usi... more This proposal is divided into two Parts: I. Exchange and oxidation of chiral allylic alcohols using chirality transfer. II. Asymmetric synthesis using Pd(Il) catalysts with chiral auxiliaries. Part I is divided into two sections: A. The determination of stereochemistries of hydroxypalladation using chirality transfer. B. Preparation of trichiral molecules. The allylic alcohols used for these studies included (R)-(-)-Zand £-3-hexen-2-ol (13a), (R)-(-)-Z-4hexen-3-ol (13b), (R)-Zand £-3-penten-2-ol (17). The chiral alcohols were prepared by reduction of the corresponding alkynones with alpine-borane reagent to give the alkynones which were reduced with either Lindlar's catalyst or Li~ to give the Z and E isomers respectively. At low [Cr] PdCLt oxidizes 13a to a mixture of (R)-Z-4-hydroxy-2-hexanone (15a) and (R)-5-hydroxy-3-hexanone (15b ). The configuration of 15a was consistent with syn hydroxypalladation. At high [Cr] (>2 M) PdCl/isomerizes 13b to (S)-Z-13a. This result is mo...

The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illu... more The springs of water in the bed of Oued Essaquia Elhamra object of our study, were chosen to illustrate impacts of entropic activities on the physico-chemical quality of these waters of springs. The analysis of the situation concerning spring, shows a rather important potential in quantity of water.However, the physico-chemical quality of the water is very low, characterized by very high mineralization and constituents at this state a source of degradation of the immediate environment, furthermore the results of the physicochemical parameters indicators of pollution : COD (chemical oxygen demand), BOD5 (biochemical oxygen demand over 5 days), dissolved oxygen (DO), nitrate (NO3), nitrite (NO2), ammonium (NH4 +), Kjeldahl nitrogen NTK, phosphates (total PT and orthophosphate PO4 2-), etc. stipulate that the waters in thesesources are exposed to heavy pollution expressed by those parameters that exceed standards. In the absence of polluting industry in the city of Laayoune; it appears...

The goal of this work was to develop polymer-based heterocycle for water purification from toxic ... more The goal of this work was to develop polymer-based heterocycle for water purification from toxic pesticides such as difenoconazole. The polymer chosen for this purpose was cellulose nanocrystalline (CNC); two cellulose based heterocycles were prepared by crosslinking with 2,6-pyridine dicarbonyl dichloride (Cell-X), and derivatizing with 2-furan carbonyl chloride (Cell-D). The synthesized cellulose-based heterocycles were characterized by SEM, proton NMR, TGA and FT-IR spectroscopy. To optimize adsorption conditions, the effect of various variable such as time, adsorbent dose, pH, temperature, and difenoconazole initial concentration were evaluated. Results showed that, the maximum difenoconazole removal percentage was about 94.7%, and 96.6% for Cell-X and Cell-D, respectively. Kinetic and thermodynamic studies on the adsorption process showed that the adsorption of difenoconazole by the two polymers is a pseudo-second order and follows the Langmuir isotherm model. The obtained valu...

Many thanks to whom our thanks go as well to them for their follow up the project. I would like t... more Many thanks to whom our thanks go as well to them for their follow up the project. I would like to thank all the technicians and staff of the chemistry department at An-Najah National University, especially Mr. Omair Al-Nabulsi and Mr. Nafiz Dweikat for their help. I would like also to express my thanks to all friends in the master program for the great and lovely time that we spent together. Last but not the least, I would like to thank my family: my parents Alham and Mohammed Melhem, for giving birth to me at the first place and supporting me spiritually and financially throughout my life. v ‫ار‬ ‫اإلقر‬ ‫تحمل‬ ‫التي‬ ‫الرسالة‬ ‫مقدم‬ ‫أدناه‬ ‫الموقع‬ ‫أنا‬ ‫ان‬ ‫العنو‬ : Synthesis and characterization of magnetic nano cellulose from olive waste (Jeft) for the effective removal of methylene blue from aquous solution

Film directing toward applications in food packaging and counter top coating with ability of inhi... more Film directing toward applications in food packaging and counter top coating with ability of inhibiting antimicrobial growth is important for maintaining food freshness and reducing bacteria transmittance. In this work, cellulose-based fatty amine with antimicrobial functionality covalently attached to cellulose backbone was synthesized. The synthesis was performed in a three-step process that involves cellulose oxidation, amination of oxidized cellulose using fatty amine and reduction. Films composites with various proportions of cellulose-based amine and cellulose triacetate were prepared. The films morphologies, tensile strengths, percent of elongation and contact angle were evaluated. The cellulose-based amine showed excellent antimicrobial activity against gram positive and moderate activity toward gram-negative bacteria. The films prevented the growth of gram-positive bacteria by 99.99%. Results indicate a good mechanical properties and bioactivities of produced film which mak...

Olive Industry Solid Waste is the remaining part of the grain of the olive industry after squeezi... more Olive Industry Solid Waste is the remaining part of the grain of the olive industry after squeezing it, it consists of wood seeds and pulp. The OISW consists of cellulose, hemicelluloses, lignin and extractives. In this work, cellulose the most valuable ingredient of OISW, was extracted in a multistep process. The process begins with pre-hydrolysis stage which opens the OISW structure and makes it more accessible for chemicals. Also in this stage, most of the hemicelluloses materials present in OISW are degraded and dissolve in water. In the prehydrolysis stage, different materials were evaluated and satisfactory results were obtained using water alone. Then OISW was subjected to the pulping process using an aqueous solution of sodium sulfide and sodium hydroxide. In the pulping stage most of the lignin is degraded and removed. The produced pulp was then subjected to a bleaching process to remove residual colored materials. Excellent results were obtained using the bleaching sequenc...

Hydroxypropyl methylcellulose in an aqueous solution upon heating tends to undergo thermal gelati... more Hydroxypropyl methylcellulose in an aqueous solution upon heating tends to undergo thermal gelation, where the polymer chains form a network and precipitate from solution. This occurs at a temperature known as thermal gelation point. Polymer precipitation causes a significant drop in the shear viscosity. This could be a disadvantage in a hot environment or in applications were heat is applied. In this work, a hydroxypropylmethyl cellulose (HPMC) was formed that undergoes thermal gelation with no polymer precipitation and with enhanced rheological properties. The target HPMC was prepared from wood pulp with a low content of carboxymethyl groups. The produced hydroxypropyl methylcellulose (CMHPMC) derivative showed unique physical properties that are not achievable with typical hydroxypropyl methylcellulose. The thermal gelation temperature of an aqueous solution of CMHPMC was increased from 55 °C for commercial HPMC to 85 °C for CMHPMC. A substitution level of carboxymethylation that...

Several new epoxy monomers were synthesized from glycidylation of functional aromatic amines cont... more Several new epoxy monomers were synthesized from glycidylation of functional aromatic amines containing hydroxyl or thiol groups. The epoxy monomers were triglycidyl-2-aminophenol, triglycidyl-2-aminothiophenol, tetraglycidyl-1,2-phenylenediamine and tetraglycidyl-4-methyl-1,2-phenylenediamine. The characterization of the epoxy monomers was carried out by FTIR and 1H NMR spectroscopy. Rheological properties of solutions of the epoxy monomers in ethanol were evaluated using an advanced rheometer. The effect of solution concentration and temperature on the viscosity of the epoxy solution was evaluated. The shear rheology study at various temperatures of the epoxy resins solutions in ethanol was carried out on solutions with concentrations ranges form 0.5 to 5 wt% and temperatures (20–70 °C). The results revealed that the tetra-functional epoxy resins behave as Newtonian liquids and its viscosity is independent on the shear rate. However, the solutions of tri-functional epoxy resins ar...