naser alandis | King Saud University (original) (raw)

Papers by naser alandis

Journal of Enzyme Inhibition, 1993

Page 1. J. Enzyme Inhibition, 1993, Vol. 7, pp. 197-202 Reprints available directly from the publ... more Page 1. J. Enzyme Inhibition, 1993, Vol. 7, pp. 197-202 Reprints available directly from the publisher Photocopying permitted by license only 01993 Harwood Academic Publishers GmbH Printed in the United States of America ...

ACS omega, Nov 18, 2020

The aim of this research work is to develop polyesteramide [LMPEA] nanocomposite coating material... more The aim of this research work is to develop polyesteramide [LMPEA] nanocomposite coating material [LMPEA/Ag] using N,N-bis(2hydroxyethyl) fatty amide obtained from non-edible Leucaena leucocephala [LL] seed oil [LLO], and maleic anhydride, reinforced with silver nanoparticles [SNPs], biosynthesized in Leucaena leucocephala leaf extract. UV, XRD, TEM, and particle size analyses confirmed the biosynthesis of NP (37.55 nm). FTIR and NMR established the structure of LMPEA formed by esterification reaction, without any solvent/diluent. Coatings were mechanically strong, well adherent to substrate, flexibility retentive, hydrophobic, and antimicrobial as evident from good scratch hardness (2−3 kg), impact resistance (150 lb per inch), bend test (1/8 inch), high water contact angle measurement value (109°) relative to pristine LMPEA coating (89°), and broad-spectrum antimicrobial behavior against MRSA, P. aeruginosa, E. coli, A. baumannii, and C. albicans. LMPEA and LMPEA/Ag exhibited high corrosion protection efficiencies, 99.81% and 99.94%, respectively, in (3.5% w/v) NaCl solution for 20 days and safe usage up to 200°C. The synthesized nanocomposite coatings provide an alternate pathway for utilization of non-edible Leucaena leucocephala seed oil through a safer chemical synthesis route, without the use/generation of any harmful solvent/toxic products, adopting "Green Chemistry" principles. Leucaena leucocephala belongs to family Fabaceae and sub-family Mimossoideae. Native to Central America and Southern Mexico, it is found in most of the tropical and subtropical areas of the world. In India, it is a well-known fodder plant in villages of Tamil Nadu. The tree is draught-resistant and well adapted to a wide range of soils and has found several applications as firewood, animal forage, construction poles, shades in plantations, erosion control, and several other uses. The parts of tree are used as food or salad in Indonesia, Thailand, and India. Different parts of plant are also used as folk medicine. 4 The seed oil of Leucaena leucocephala [LLO] is rich in linoleic, oleic, palmitic, and stearic acid, which comprise more than 92% of total fatty acids of LLO, and also has a higher content of tocopherols. 5 LLO has also shown antibacterial and antifungal properties. 6 The leaves of Leucaena leucocephala plant [LL] are rich in phytochemicals such as alkaloids, flavonoids, tannins, and

Progress in Organic Coatings, Dec 1, 2012

ABSTRACT Virgin olive oil (VOO) based polyetheramide (PEtA) was developed from N-N'-bis(2... more ABSTRACT Virgin olive oil (VOO) based polyetheramide (PEtA) was developed from N-N'-bis(2-hydroxyl ethyl) olive fatty amide (HEOA) and orcinol through condensation polymerization. PEtA was further treated with toluylene 2,4-diisocynate (TDI) with different percentages (20-30 wt%) via addition polymerization to obtain poly(ether amide urethane) (PEtAU). The structural elucidation of HEOA, PEtA and PEtAU were carried out by FT-IR, H-1 NMR and C-13 NMR spectroscopic techniques. Physico-chemical and physico-mechanical properties of the material were investigated by standard methods. Thermal stability and curing behavior of virgin olive oil, HEOA, and PEtAU were assessed by thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The corrosion behavior was investigated by potentiodynamic polarization measurements in different corrosive environments (3.5 wt% NCl, 5 wt% NaCl, 3.5 wt% NaOH, tap water) at room temperature. The results showed that UPEtA coatings exhibit good physico-mechanical as well as corrosion resistance performance and can be safely used up to 200 degrees C. The work is an attempt for alternate utilization of olive oil. (c) 2012 Elsevier B.V. All rights reserved.

E-polymers, Oct 26, 2017

Jatropha oil (JO) is an inedible oil mainly used in biodiesel. We have attempted to prepare a JO-... more Jatropha oil (JO) is an inedible oil mainly used in biodiesel. We have attempted to prepare a JO-based polyesteramide/clay composite using a one-pot, two-step reaction, for application as a protective coating. The aim of the work is to utilize JO for its value-added application by preparing a JO polyesteramide/clay composite, to investigate the potential of the prepared composite as a protective coating, and also to study the effect of loaded clay on the structure, morphology, thermal stability and coating properties of the composite. The formation of composites was confirmed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and atomic force microscope (AFM) studies. The coating properties were studied by standard physicomechanical and corrosion resistance tests in corrosive media (3.5 wt% HCl, 3.5 wt% NaCl and tap water). The thermal stability was assessed by differential scanning calorimetry (DSC), thermogravimetric (TGA) and derivative thermogravimetric (DTG) analyses. The coatings showed good physico-mechanical and corrosion resistance performance and can be safely used up to 275°C. The approach paves way towards an alternate value addition to a non-edible oil.

Tetrahedron Letters, 1987

The addition of formamide to l-butanol, solvent used to polymerize ndrbornene by RuC13, 3H20, str... more The addition of formamide to l-butanol, solvent used to polymerize ndrbornene by RuC13, 3H20, strongly modifies the stereochemistry of this reaction. Les techniques de polymerisation du norbornene, aussi bien de type vinylique que par ouverture du cycle, ont don+ lieu a de tres nombreux travauxIs2. Nous nous sommes plus particulierement interesses a la polymerisation par ouverture du cycle en milieu alcoolique, amorcee par RuC13, 3H20 2 : n I 0-#yJ#" Dans le cas des olefines cycliques du type norbornene, Calderon et ~011.~ ont mis en evidence l'existence de deux classes de catalyseurs : les non-stereoselectifs et les stereoselectifs auxquels appartient le systeme RuC13, 3H20. RESULTATS Par addition au milieu de formamide-solvant polaire et structure, utilise largement dans notre laboratoire comme milieu r@actionne14-nous mettons ici en evidence pour la premiere fois dans ce type de reactions qu'un catalyseur stereoselectif peut aussi etre non-stereoselectif. @and le formamide est introduit, soit avant soit simultanement avec le butanol, la reaction de polymerisation ne se fait pas. Dans le time temps, une coloration rouge sombre apparait dans le milieu. Cette coloration est sans doute due a la formation d'un complexe stable formamide-ruthenium par substitution d'une molecule d'eau lors de la premiere @tape de la reaction5 : RuC13, 3H20 t HCONH2 ___t RuC~~,(H~O)~, HCONHZ + H20 Le formamide entre alors en competition avec l'alcool lors de l'etape dissociative correspondant a l'echange de ligands au niveau du catalyseur. Afin d'eviter ce blocage irreversible du systeme catalytique, nous avons laisse un temps d'interaction d'une heure entre le catalyseur et le butanol avant d'introduire le formamide et le norbornene. Cette periode d'interaction permet la substitution d'une molecule d'eau du complexe initial RuC13, 3H20 par une molecule d'alcool pour former un nouveau complexe (RuC13 (H20)2 BuOH), ce dernier evoluant ensuite en hydrure metallique2. Cette technique nous a permis de realiser la polymerisation du norbornene avec dans certains cas une forte modification de la stereochimie du polymere. Les resultats sont rassembles dans le tableau I. 9-I1 a et@ @tabli, dans les travaux anterieurs, que la reaction en milieu classique est d'ordre 1 par rapport d RuC13, 3H20 (cf. 2). 10-a) I.

Journal of environmental science & engineering, Apr 30, 2010

Sorption of radioisotopes onto a stable colloidal phase may significantly enhance their transport... more Sorption of radioisotopes onto a stable colloidal phase may significantly enhance their transport in groundwater. The adsorption of cesium (Cs(superscript +)) and strontium (Sr(superscript ++)) from aqueous solutions onto commercial natural bentonite (NB) was studied as a function of contact time, temperature, bentonite mass and bentonite treatment (washing and heat treatment) on the uptake of these cations, independently. The heat treatment was 700℃ and washed bentonite samples termed by CB and WB respectively. Batch experiments results showed that the adsorptive capacity of NB at 293, 298 and 308 K for Cs(superscript +) and Sr(superscript ++) were 110, 105, 104 and 35, 33.6, 31.8mg/g respectively. The experimental results for strontium adsorption 293, 298 and 308 K fit well to a Langmuirian and Frendlich type isotherm but cesium adsorption fit better with Langmuir than Frendlich isotherm. Thermodynamic functions, the change of free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption were also calculated for each cation. These parameters showed that the adsorption of Cs(superscript +) and Sr(superscript ++) onto NB was feasible, spontaneous and exothermic. The adsorption of Sr(superscript ++) and Cs(superscript +) increases with increasing pH (pH 2-8) and follows pseudo-second order kinetics reaching equilibrium after an equilibration time of 300 and 5 min respectively. The adsorbed amount of Cs(superscript +) not affected by washing of NB but affected by the heat treatment. However the adsorbed amount of Sr(superscript ++) on WB was higher than NB and CB.

Grasas y Aceites, 2017

For the first time, we report the characterization of triacylglycerols and fatty acids in Leucaen... more For the first time, we report the characterization of triacylglycerols and fatty acids in Leucaena (Leucaena leucephala) oil [LUCO], an unexplored nontraditional non-medicinal plant belonging to the family Fabaceae. LUCO was converted to fatty acid methyl esters (FAMEs). We analyzed the triacylglycerols (TAGs) of pure LUCO and their FAMEs by time-of-flight mass spectrometry (TOF-MS) followed by multivariate analysis for discrimination among the FAMEs. Our investigations for the analysis of LUCO samples represent noble features of glycerides. A new type of ion source, coupled with high-resolution TOF-MS was applied for the comprehensive analysis of triacylglycerols. The composition of fatty acid based LUCO oil was studied using Gas Chromatography (GC-FID). The major fatty acid components of LUCO oil are linoleic acid (52.08%) oleic acid (21.26%), palmitic acid (7.91%) and stearic acid (6.01%). A metal analysis in LUCO was done by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)....

Progress in Reaction Kinetics and Mechanism, 2012

Isothermal decomposition of unirradiated and γ-irradiated gallium acetylacetonate Ga(acac)3 with ... more Isothermal decomposition of unirradiated and γ-irradiated gallium acetylacetonate Ga(acac)3 with 103 kGy total γ-ray dose was carried out in static air. The isothermal operating temperatures were 160, 170, 180 and 190°C. The kinetics of decomposition were followed using both model-fitting and model-free approaches. The results of model fitting application on the investigated data showed that the decomposition behaviour was best described by phase-boundary controlled reaction (R2). Kinetic parameters of the decomposition process were calculated and evaluated. Analysis of the data using model free approach signifies the dependency of Ea on extent of conversion (α). Pre-γ-irradiation of gallium acetylacetonate Ga(acac)3 with 103 kGy total γ-ray dose has almost no effect on the kinetic parameters.

E-polymers, 2023

This article describes the synthesis of polyesteramide (PEA) resin from Leucaena leucocephala oil... more This article describes the synthesis of polyesteramide (PEA) resin from Leucaena leucocephala oil (LLO) obtained from seeds of L. leucocephala tree, locally grown in King Saud University Campus. LLO was transformed into amide diol by based catalyzed amidation reaction, followed by esterification reaction with malic acid (MA), that resulted in LLO-based PEA (LPEA). The synthesis was performed without using any solvent or catalyst. Fouriertransformation infrared spectroscopy and nuclear magnetic resonance confirmed the formation of LPEA by the introduction of amide and ester moieties. LPEA was further reinforced with nano graphene oxide (GO) and fabricated into nanocomposite corrosion protective coatings (LPEA/GO). LPEA/GO coatings obtained were tough, flexibility retentive and showed good corrosion resistance performance toward 3.5 w/w% NaCl medium. Thermogravimetric analysis confirmed good thermal stability of coatings with safe usage up to 200°C.

Jordan journal of chemistry, 2008

The present study examined the application of a commercial natural bentonite (untreated, NB) for ... more The present study examined the application of a commercial natural bentonite (untreated, NB) for the removal of Co (II) ions from aqueous solutions. Specific surface area of the sample was determined by means of N2 adsorption-desorption at 77 K applying the BET method. X-ray powder diffraction (XRD) was also used to characterize the (NB). The effects of pH, adsorption time, cobalt ion concentration, bentonite doses, temperature and the NB treatment (calcination of NB at 700 O C and washing by water) on the adsorption process of Co (II) were examined. The optimum pH for adsorption was found to be 6.0. The data demonstrated that the amount of Co (II) adsorbed on bentonite increases rapidly during the first hour, thereafter adsorption becomes linear with time. Pseudo-second-order model described best the kinetics of the reaction. The thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy) were determined and discussed. The adsorption of Co(II) on NB appeared to follow Langmuir adsorption. The process was found to be spontaneous and endothermic under normal conditions. The adsorbed amount of Co (II) on washed bentonite (WB) was increased by 100% compared to NB and bentonite calcined at 700oC (CB). Our results show that bentonite could especially WB be considered as a potential adsorbent for Co (II) removal from aqueous

International Journal of Polymer Analysis and Characterization, 2021

Abstract Poly(urethane-malonic-esteramide) (PUMEA), a novel resin synthesized from corn oil-based... more Abstract Poly(urethane-malonic-esteramide) (PUMEA), a novel resin synthesized from corn oil-based fatty amide, malonic acid, and isophorone diisocynate, was modified by introducing different amounts of multi-walled carbon nanotubes (MWCNTs) into the polymer matrix and cured at room temperature. The chemical structure and surface morphology were characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and field emission scanning electron microscopy, and thermal analysis was carried out by thermogravimetric analysis and differential scanning calorimetry. The PUMEA/MWCNTs composites were coated on mild steel panel and cured at room temperature. Hydrophobicity and physico-mechanical properties of the coatings were extracted by measuring contact angle, scratch and pencil hardness, bending, cross-hatch adhesion, impact, and gloss. The corrosion resistance was proved measuring the potentiodynamic polarization and electrochemical impedance of a PUMEA-coated mild steel panel immersed in a 3.5 wt% NaCl solution for 40 days. Thermal studies revealed that the PUMEA coating can be safely used up to 250 °C.

Journal of King Saud University - Science

Journal of King Abdulaziz University-Science, 2010

The aim of the present work is to investigate the ability of commercial natural bentonite (untrea... more The aim of the present work is to investigate the ability of commercial natural bentonite (untreated) (NB) to remove silver ions from aqueous solution. Specific surface area of the sample was determined as a result of N 2 adsorption-desorption at 77 K using BET method. X-ray powder diffraction (XRD) was used to characterize the (NB). Towards this aim, batch adsorption experiments were carried out and the effect of various parameters on this removal process has been investigated. The effects of pH, adsorption time, silver ion concentration, bentonite doses, Temperature and the NB treatment (calcinations and washing) on the adsorption process were examined. The optimum pH for adsorption was found to be 4-8. It was found that NB treatment has a substantial effect on the metal uptake. In adsorption studies, residual silver ions concentration reached equilibrium in a short duration of 15 min. The paper discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Adsorption of Ag + on NB appeared to follow Langmuir isotherm. Our results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions. Additionally, a pseudo-second-order rate model was adopted to describe the kinetics of adsorption. In desorption experiment, an approximately (15%) desorption yield was obtained for silver ions.

International Journal of Polymer Analysis and Characterization, 2017

ABSTRACT Corn oil-based poly(urethane-ester)amide was synthesized from corn oil-based fatty amide... more ABSTRACT Corn oil-based poly(urethane-ester)amide was synthesized from corn oil-based fatty amide diol, camphoric acid, and tolylene 2,4-diisocyanate. The structure of corn polyesteramide and corn poly(urethane-ester)amide (CPEA) was confirmed by Fourier transform infrared, 1H NMR, and 13C NMR spectroscopic techniques. CPUEA coatings were made on mild steel strips and their physicomechanical analysis (scratch hardness, impact test, conical mandrel test, and pencil hardness tests) was performed by standard methods. The surface morphology of coatings was observed by scanning electron microscopy and thermal stability was assessed by thermogravimetric analysis/differential scanning calorimetry. Anticorrosion properties of CPUEA were observed in acidic, saline, and tap water medium at room temperature using potentiodynamic polarization technique. The results of CPUEA coatings exhibit good physicomechanical and anticorrosive properties and can find application up to 175°C.

Nanoscale Research Letters, 2015

Journal of the Iranian Chemical Society, 2013

Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely ... more Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely used for the removal of heavy metals. The aim of this work is to investigate the adsorption potential of commercial natural bentonite (NB) in the removal of Pb (II) ions from aqueous solution. The effect of different variables, such as, concentration of Pb, mass of NB, pH, time, NB washing and heat treatment and temperature was investigated. The bentonite sample under the heat and washed treatment are labeled as CB and WB respectively. The adsorption experiments were carried out using batch process. The equilibrium time for Pb (II) adsorption on NB was 5 min, the processes conforming to second order kinetics. NB had a much higher adsorption capacity for Pb (II) with the Langmuir monolayer capacity (qm) of 107, 110 and 120 mg g− 1 at 293, 313 and 333 K respectively compared to others adsorbents. Thermodynamic parameters such as H°, S° and G° were calculated. The adsorption process was found to be endothermic and spontaneous. The enthalpy change for Pb (II) by NB adsorption has been estimated as 33 kJ mol−1, indicating that the adsorption of Pb (II) by NB corresponds to a physical reaction. The adsorption capacity of washed bentonite WB was very high compared to NB and CB

Journal of Nanomaterials, 2015

Reverse osmosis (RO) membranes modified withSnO2nanoparticles of varied concentrations (0.001–0.1... more Reverse osmosis (RO) membranes modified withSnO2nanoparticles of varied concentrations (0.001–0.1 wt.%) were developed via in situ interfacial polymerization (IP) of trimesoyl chloride (TMC) andm-phenylenediamine (MPD) on nanoporous polysulfone supports. The nanoparticles dispersed in the dense nodular polyamide on the polysulfone side. The effects of IP reaction time andSnO2loading on membrane separation performance were studied. The modified reverse osmosis membranes were characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), contact angle measurement, and atomic force microscopy (AFM). The synthesizedSnO2nanoparticles size varies between 10 and 30 nm. The results exhibited a smooth membrane surface and average surface roughness from 31 to 68 nm. Moreover, hydrophilicity was enhanced and contact angle decreased. The outcomes showed that an IP reaction time was essential to...

International Journal of Physical Sciences, 2008

Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely ... more Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely used for the removal of heavy metals. The aim of this work is to investigate the adsorption potential of commercial natural bentonite (NB) in the removal of Pb (II) ions from aqueous solution. The effect of different variables, such as, concentration of Pb, mass of NB, pH, time, NB washing and heat treatment and temperature was investigated. The bentonite sample under the heat and washed treatment are labeled as CB and WB respectively. The adsorption experiments were carried out using batch process. The equilibrium time for Pb (II) adsorption on NB was 5 min, the processes conforming to second order kinetics. NB had a much higher adsorption capacity for Pb (II) with the Langmuir monolayer capacity (qm) of 107, 110 and 120 mg g− 1 at 293, 313 and 333 K respectively compared to others adsorbents. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° were calculated. The adsorption process was ...

Arab Gulf Journal of Scientific Research, 2009

The adsorption kinetics of natural commercial bentonite (NB) with respect to Cu (II) has been stu... more The adsorption kinetics of natural commercial bentonite (NB) with respect to Cu (II) has been studied in order to consider its application to purify metal finishing wastewaters. The batch method has been employed, using metal concentrations in solution ranging from 40 to 2000 mg/l. We have investigated how solution pH, temperature, adsorbent amount, contact time, washing and calcinations of bentonite (the calcinations of bentonite at 700 °C and washed bentonite termed by CB and WB, respectively) affect this process. Results of kinetic experiments showed that Cu (II) adsorption rate was fast, and more than 90% of Cu adsorption occurred within 5 min. Among the kinetic models tested, the adsorption kinetics was best described by the pseudo-second-order equation. The adsorption capacity of Cu (II) ions on NB has increased with increasing pH, adsorbent amount and temperature. The Langmuir adsorption isotherm properly describes the equilibrium adsorption and the maximum adsorption capacit...

Toxicological and …, 1994

Page 1. Toxicological and Environmental Chemisiry, Vol. 43, pp. 141-145 © 1994 Gordon and Breach ... more Page 1. Toxicological and Environmental Chemisiry, Vol. 43, pp. 141-145 © 1994 Gordon and Breach Science Publishers SA Reprints available directly from the publisher Printed in Malaysia Photocopying permitted by license ...

Journal of Enzyme Inhibition, 1993

Page 1. J. Enzyme Inhibition, 1993, Vol. 7, pp. 197-202 Reprints available directly from the publ... more Page 1. J. Enzyme Inhibition, 1993, Vol. 7, pp. 197-202 Reprints available directly from the publisher Photocopying permitted by license only 01993 Harwood Academic Publishers GmbH Printed in the United States of America ...

ACS omega, Nov 18, 2020

The aim of this research work is to develop polyesteramide [LMPEA] nanocomposite coating material... more The aim of this research work is to develop polyesteramide [LMPEA] nanocomposite coating material [LMPEA/Ag] using N,N-bis(2hydroxyethyl) fatty amide obtained from non-edible Leucaena leucocephala [LL] seed oil [LLO], and maleic anhydride, reinforced with silver nanoparticles [SNPs], biosynthesized in Leucaena leucocephala leaf extract. UV, XRD, TEM, and particle size analyses confirmed the biosynthesis of NP (37.55 nm). FTIR and NMR established the structure of LMPEA formed by esterification reaction, without any solvent/diluent. Coatings were mechanically strong, well adherent to substrate, flexibility retentive, hydrophobic, and antimicrobial as evident from good scratch hardness (2−3 kg), impact resistance (150 lb per inch), bend test (1/8 inch), high water contact angle measurement value (109°) relative to pristine LMPEA coating (89°), and broad-spectrum antimicrobial behavior against MRSA, P. aeruginosa, E. coli, A. baumannii, and C. albicans. LMPEA and LMPEA/Ag exhibited high corrosion protection efficiencies, 99.81% and 99.94%, respectively, in (3.5% w/v) NaCl solution for 20 days and safe usage up to 200°C. The synthesized nanocomposite coatings provide an alternate pathway for utilization of non-edible Leucaena leucocephala seed oil through a safer chemical synthesis route, without the use/generation of any harmful solvent/toxic products, adopting "Green Chemistry" principles. Leucaena leucocephala belongs to family Fabaceae and sub-family Mimossoideae. Native to Central America and Southern Mexico, it is found in most of the tropical and subtropical areas of the world. In India, it is a well-known fodder plant in villages of Tamil Nadu. The tree is draught-resistant and well adapted to a wide range of soils and has found several applications as firewood, animal forage, construction poles, shades in plantations, erosion control, and several other uses. The parts of tree are used as food or salad in Indonesia, Thailand, and India. Different parts of plant are also used as folk medicine. 4 The seed oil of Leucaena leucocephala [LLO] is rich in linoleic, oleic, palmitic, and stearic acid, which comprise more than 92% of total fatty acids of LLO, and also has a higher content of tocopherols. 5 LLO has also shown antibacterial and antifungal properties. 6 The leaves of Leucaena leucocephala plant [LL] are rich in phytochemicals such as alkaloids, flavonoids, tannins, and

Progress in Organic Coatings, Dec 1, 2012

ABSTRACT Virgin olive oil (VOO) based polyetheramide (PEtA) was developed from N-N'-bis(2... more ABSTRACT Virgin olive oil (VOO) based polyetheramide (PEtA) was developed from N-N'-bis(2-hydroxyl ethyl) olive fatty amide (HEOA) and orcinol through condensation polymerization. PEtA was further treated with toluylene 2,4-diisocynate (TDI) with different percentages (20-30 wt%) via addition polymerization to obtain poly(ether amide urethane) (PEtAU). The structural elucidation of HEOA, PEtA and PEtAU were carried out by FT-IR, H-1 NMR and C-13 NMR spectroscopic techniques. Physico-chemical and physico-mechanical properties of the material were investigated by standard methods. Thermal stability and curing behavior of virgin olive oil, HEOA, and PEtAU were assessed by thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The corrosion behavior was investigated by potentiodynamic polarization measurements in different corrosive environments (3.5 wt% NCl, 5 wt% NaCl, 3.5 wt% NaOH, tap water) at room temperature. The results showed that UPEtA coatings exhibit good physico-mechanical as well as corrosion resistance performance and can be safely used up to 200 degrees C. The work is an attempt for alternate utilization of olive oil. (c) 2012 Elsevier B.V. All rights reserved.

E-polymers, Oct 26, 2017

Jatropha oil (JO) is an inedible oil mainly used in biodiesel. We have attempted to prepare a JO-... more Jatropha oil (JO) is an inedible oil mainly used in biodiesel. We have attempted to prepare a JO-based polyesteramide/clay composite using a one-pot, two-step reaction, for application as a protective coating. The aim of the work is to utilize JO for its value-added application by preparing a JO polyesteramide/clay composite, to investigate the potential of the prepared composite as a protective coating, and also to study the effect of loaded clay on the structure, morphology, thermal stability and coating properties of the composite. The formation of composites was confirmed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and atomic force microscope (AFM) studies. The coating properties were studied by standard physicomechanical and corrosion resistance tests in corrosive media (3.5 wt% HCl, 3.5 wt% NaCl and tap water). The thermal stability was assessed by differential scanning calorimetry (DSC), thermogravimetric (TGA) and derivative thermogravimetric (DTG) analyses. The coatings showed good physico-mechanical and corrosion resistance performance and can be safely used up to 275°C. The approach paves way towards an alternate value addition to a non-edible oil.

Tetrahedron Letters, 1987

The addition of formamide to l-butanol, solvent used to polymerize ndrbornene by RuC13, 3H20, str... more The addition of formamide to l-butanol, solvent used to polymerize ndrbornene by RuC13, 3H20, strongly modifies the stereochemistry of this reaction. Les techniques de polymerisation du norbornene, aussi bien de type vinylique que par ouverture du cycle, ont don+ lieu a de tres nombreux travauxIs2. Nous nous sommes plus particulierement interesses a la polymerisation par ouverture du cycle en milieu alcoolique, amorcee par RuC13, 3H20 2 : n I 0-#yJ#" Dans le cas des olefines cycliques du type norbornene, Calderon et ~011.~ ont mis en evidence l'existence de deux classes de catalyseurs : les non-stereoselectifs et les stereoselectifs auxquels appartient le systeme RuC13, 3H20. RESULTATS Par addition au milieu de formamide-solvant polaire et structure, utilise largement dans notre laboratoire comme milieu r@actionne14-nous mettons ici en evidence pour la premiere fois dans ce type de reactions qu'un catalyseur stereoselectif peut aussi etre non-stereoselectif. @and le formamide est introduit, soit avant soit simultanement avec le butanol, la reaction de polymerisation ne se fait pas. Dans le time temps, une coloration rouge sombre apparait dans le milieu. Cette coloration est sans doute due a la formation d'un complexe stable formamide-ruthenium par substitution d'une molecule d'eau lors de la premiere @tape de la reaction5 : RuC13, 3H20 t HCONH2 ___t RuC~~,(H~O)~, HCONHZ + H20 Le formamide entre alors en competition avec l'alcool lors de l'etape dissociative correspondant a l'echange de ligands au niveau du catalyseur. Afin d'eviter ce blocage irreversible du systeme catalytique, nous avons laisse un temps d'interaction d'une heure entre le catalyseur et le butanol avant d'introduire le formamide et le norbornene. Cette periode d'interaction permet la substitution d'une molecule d'eau du complexe initial RuC13, 3H20 par une molecule d'alcool pour former un nouveau complexe (RuC13 (H20)2 BuOH), ce dernier evoluant ensuite en hydrure metallique2. Cette technique nous a permis de realiser la polymerisation du norbornene avec dans certains cas une forte modification de la stereochimie du polymere. Les resultats sont rassembles dans le tableau I. 9-I1 a et@ @tabli, dans les travaux anterieurs, que la reaction en milieu classique est d'ordre 1 par rapport d RuC13, 3H20 (cf. 2). 10-a) I.

Journal of environmental science & engineering, Apr 30, 2010

Sorption of radioisotopes onto a stable colloidal phase may significantly enhance their transport... more Sorption of radioisotopes onto a stable colloidal phase may significantly enhance their transport in groundwater. The adsorption of cesium (Cs(superscript +)) and strontium (Sr(superscript ++)) from aqueous solutions onto commercial natural bentonite (NB) was studied as a function of contact time, temperature, bentonite mass and bentonite treatment (washing and heat treatment) on the uptake of these cations, independently. The heat treatment was 700℃ and washed bentonite samples termed by CB and WB respectively. Batch experiments results showed that the adsorptive capacity of NB at 293, 298 and 308 K for Cs(superscript +) and Sr(superscript ++) were 110, 105, 104 and 35, 33.6, 31.8mg/g respectively. The experimental results for strontium adsorption 293, 298 and 308 K fit well to a Langmuirian and Frendlich type isotherm but cesium adsorption fit better with Langmuir than Frendlich isotherm. Thermodynamic functions, the change of free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption were also calculated for each cation. These parameters showed that the adsorption of Cs(superscript +) and Sr(superscript ++) onto NB was feasible, spontaneous and exothermic. The adsorption of Sr(superscript ++) and Cs(superscript +) increases with increasing pH (pH 2-8) and follows pseudo-second order kinetics reaching equilibrium after an equilibration time of 300 and 5 min respectively. The adsorbed amount of Cs(superscript +) not affected by washing of NB but affected by the heat treatment. However the adsorbed amount of Sr(superscript ++) on WB was higher than NB and CB.

Grasas y Aceites, 2017

For the first time, we report the characterization of triacylglycerols and fatty acids in Leucaen... more For the first time, we report the characterization of triacylglycerols and fatty acids in Leucaena (Leucaena leucephala) oil [LUCO], an unexplored nontraditional non-medicinal plant belonging to the family Fabaceae. LUCO was converted to fatty acid methyl esters (FAMEs). We analyzed the triacylglycerols (TAGs) of pure LUCO and their FAMEs by time-of-flight mass spectrometry (TOF-MS) followed by multivariate analysis for discrimination among the FAMEs. Our investigations for the analysis of LUCO samples represent noble features of glycerides. A new type of ion source, coupled with high-resolution TOF-MS was applied for the comprehensive analysis of triacylglycerols. The composition of fatty acid based LUCO oil was studied using Gas Chromatography (GC-FID). The major fatty acid components of LUCO oil are linoleic acid (52.08%) oleic acid (21.26%), palmitic acid (7.91%) and stearic acid (6.01%). A metal analysis in LUCO was done by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)....

Progress in Reaction Kinetics and Mechanism, 2012

Isothermal decomposition of unirradiated and γ-irradiated gallium acetylacetonate Ga(acac)3 with ... more Isothermal decomposition of unirradiated and γ-irradiated gallium acetylacetonate Ga(acac)3 with 103 kGy total γ-ray dose was carried out in static air. The isothermal operating temperatures were 160, 170, 180 and 190°C. The kinetics of decomposition were followed using both model-fitting and model-free approaches. The results of model fitting application on the investigated data showed that the decomposition behaviour was best described by phase-boundary controlled reaction (R2). Kinetic parameters of the decomposition process were calculated and evaluated. Analysis of the data using model free approach signifies the dependency of Ea on extent of conversion (α). Pre-γ-irradiation of gallium acetylacetonate Ga(acac)3 with 103 kGy total γ-ray dose has almost no effect on the kinetic parameters.

E-polymers, 2023

This article describes the synthesis of polyesteramide (PEA) resin from Leucaena leucocephala oil... more This article describes the synthesis of polyesteramide (PEA) resin from Leucaena leucocephala oil (LLO) obtained from seeds of L. leucocephala tree, locally grown in King Saud University Campus. LLO was transformed into amide diol by based catalyzed amidation reaction, followed by esterification reaction with malic acid (MA), that resulted in LLO-based PEA (LPEA). The synthesis was performed without using any solvent or catalyst. Fouriertransformation infrared spectroscopy and nuclear magnetic resonance confirmed the formation of LPEA by the introduction of amide and ester moieties. LPEA was further reinforced with nano graphene oxide (GO) and fabricated into nanocomposite corrosion protective coatings (LPEA/GO). LPEA/GO coatings obtained were tough, flexibility retentive and showed good corrosion resistance performance toward 3.5 w/w% NaCl medium. Thermogravimetric analysis confirmed good thermal stability of coatings with safe usage up to 200°C.

Jordan journal of chemistry, 2008

The present study examined the application of a commercial natural bentonite (untreated, NB) for ... more The present study examined the application of a commercial natural bentonite (untreated, NB) for the removal of Co (II) ions from aqueous solutions. Specific surface area of the sample was determined by means of N2 adsorption-desorption at 77 K applying the BET method. X-ray powder diffraction (XRD) was also used to characterize the (NB). The effects of pH, adsorption time, cobalt ion concentration, bentonite doses, temperature and the NB treatment (calcination of NB at 700 O C and washing by water) on the adsorption process of Co (II) were examined. The optimum pH for adsorption was found to be 6.0. The data demonstrated that the amount of Co (II) adsorbed on bentonite increases rapidly during the first hour, thereafter adsorption becomes linear with time. Pseudo-second-order model described best the kinetics of the reaction. The thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy) were determined and discussed. The adsorption of Co(II) on NB appeared to follow Langmuir adsorption. The process was found to be spontaneous and endothermic under normal conditions. The adsorbed amount of Co (II) on washed bentonite (WB) was increased by 100% compared to NB and bentonite calcined at 700oC (CB). Our results show that bentonite could especially WB be considered as a potential adsorbent for Co (II) removal from aqueous

International Journal of Polymer Analysis and Characterization, 2021

Abstract Poly(urethane-malonic-esteramide) (PUMEA), a novel resin synthesized from corn oil-based... more Abstract Poly(urethane-malonic-esteramide) (PUMEA), a novel resin synthesized from corn oil-based fatty amide, malonic acid, and isophorone diisocynate, was modified by introducing different amounts of multi-walled carbon nanotubes (MWCNTs) into the polymer matrix and cured at room temperature. The chemical structure and surface morphology were characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and field emission scanning electron microscopy, and thermal analysis was carried out by thermogravimetric analysis and differential scanning calorimetry. The PUMEA/MWCNTs composites were coated on mild steel panel and cured at room temperature. Hydrophobicity and physico-mechanical properties of the coatings were extracted by measuring contact angle, scratch and pencil hardness, bending, cross-hatch adhesion, impact, and gloss. The corrosion resistance was proved measuring the potentiodynamic polarization and electrochemical impedance of a PUMEA-coated mild steel panel immersed in a 3.5 wt% NaCl solution for 40 days. Thermal studies revealed that the PUMEA coating can be safely used up to 250 °C.

Journal of King Saud University - Science

Journal of King Abdulaziz University-Science, 2010

The aim of the present work is to investigate the ability of commercial natural bentonite (untrea... more The aim of the present work is to investigate the ability of commercial natural bentonite (untreated) (NB) to remove silver ions from aqueous solution. Specific surface area of the sample was determined as a result of N 2 adsorption-desorption at 77 K using BET method. X-ray powder diffraction (XRD) was used to characterize the (NB). Towards this aim, batch adsorption experiments were carried out and the effect of various parameters on this removal process has been investigated. The effects of pH, adsorption time, silver ion concentration, bentonite doses, Temperature and the NB treatment (calcinations and washing) on the adsorption process were examined. The optimum pH for adsorption was found to be 4-8. It was found that NB treatment has a substantial effect on the metal uptake. In adsorption studies, residual silver ions concentration reached equilibrium in a short duration of 15 min. The paper discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Adsorption of Ag + on NB appeared to follow Langmuir isotherm. Our results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions. Additionally, a pseudo-second-order rate model was adopted to describe the kinetics of adsorption. In desorption experiment, an approximately (15%) desorption yield was obtained for silver ions.

International Journal of Polymer Analysis and Characterization, 2017

ABSTRACT Corn oil-based poly(urethane-ester)amide was synthesized from corn oil-based fatty amide... more ABSTRACT Corn oil-based poly(urethane-ester)amide was synthesized from corn oil-based fatty amide diol, camphoric acid, and tolylene 2,4-diisocyanate. The structure of corn polyesteramide and corn poly(urethane-ester)amide (CPEA) was confirmed by Fourier transform infrared, 1H NMR, and 13C NMR spectroscopic techniques. CPUEA coatings were made on mild steel strips and their physicomechanical analysis (scratch hardness, impact test, conical mandrel test, and pencil hardness tests) was performed by standard methods. The surface morphology of coatings was observed by scanning electron microscopy and thermal stability was assessed by thermogravimetric analysis/differential scanning calorimetry. Anticorrosion properties of CPUEA were observed in acidic, saline, and tap water medium at room temperature using potentiodynamic polarization technique. The results of CPUEA coatings exhibit good physicomechanical and anticorrosive properties and can find application up to 175°C.

Nanoscale Research Letters, 2015

Journal of the Iranian Chemical Society, 2013

Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely ... more Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely used for the removal of heavy metals. The aim of this work is to investigate the adsorption potential of commercial natural bentonite (NB) in the removal of Pb (II) ions from aqueous solution. The effect of different variables, such as, concentration of Pb, mass of NB, pH, time, NB washing and heat treatment and temperature was investigated. The bentonite sample under the heat and washed treatment are labeled as CB and WB respectively. The adsorption experiments were carried out using batch process. The equilibrium time for Pb (II) adsorption on NB was 5 min, the processes conforming to second order kinetics. NB had a much higher adsorption capacity for Pb (II) with the Langmuir monolayer capacity (qm) of 107, 110 and 120 mg g− 1 at 293, 313 and 333 K respectively compared to others adsorbents. Thermodynamic parameters such as H°, S° and G° were calculated. The adsorption process was found to be endothermic and spontaneous. The enthalpy change for Pb (II) by NB adsorption has been estimated as 33 kJ mol−1, indicating that the adsorption of Pb (II) by NB corresponds to a physical reaction. The adsorption capacity of washed bentonite WB was very high compared to NB and CB

Journal of Nanomaterials, 2015

Reverse osmosis (RO) membranes modified withSnO2nanoparticles of varied concentrations (0.001–0.1... more Reverse osmosis (RO) membranes modified withSnO2nanoparticles of varied concentrations (0.001–0.1 wt.%) were developed via in situ interfacial polymerization (IP) of trimesoyl chloride (TMC) andm-phenylenediamine (MPD) on nanoporous polysulfone supports. The nanoparticles dispersed in the dense nodular polyamide on the polysulfone side. The effects of IP reaction time andSnO2loading on membrane separation performance were studied. The modified reverse osmosis membranes were characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), contact angle measurement, and atomic force microscopy (AFM). The synthesizedSnO2nanoparticles size varies between 10 and 30 nm. The results exhibited a smooth membrane surface and average surface roughness from 31 to 68 nm. Moreover, hydrophilicity was enhanced and contact angle decreased. The outcomes showed that an IP reaction time was essential to...

International Journal of Physical Sciences, 2008

Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely ... more Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely used for the removal of heavy metals. The aim of this work is to investigate the adsorption potential of commercial natural bentonite (NB) in the removal of Pb (II) ions from aqueous solution. The effect of different variables, such as, concentration of Pb, mass of NB, pH, time, NB washing and heat treatment and temperature was investigated. The bentonite sample under the heat and washed treatment are labeled as CB and WB respectively. The adsorption experiments were carried out using batch process. The equilibrium time for Pb (II) adsorption on NB was 5 min, the processes conforming to second order kinetics. NB had a much higher adsorption capacity for Pb (II) with the Langmuir monolayer capacity (qm) of 107, 110 and 120 mg g− 1 at 293, 313 and 333 K respectively compared to others adsorbents. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° were calculated. The adsorption process was ...

Arab Gulf Journal of Scientific Research, 2009

The adsorption kinetics of natural commercial bentonite (NB) with respect to Cu (II) has been stu... more The adsorption kinetics of natural commercial bentonite (NB) with respect to Cu (II) has been studied in order to consider its application to purify metal finishing wastewaters. The batch method has been employed, using metal concentrations in solution ranging from 40 to 2000 mg/l. We have investigated how solution pH, temperature, adsorbent amount, contact time, washing and calcinations of bentonite (the calcinations of bentonite at 700 °C and washed bentonite termed by CB and WB, respectively) affect this process. Results of kinetic experiments showed that Cu (II) adsorption rate was fast, and more than 90% of Cu adsorption occurred within 5 min. Among the kinetic models tested, the adsorption kinetics was best described by the pseudo-second-order equation. The adsorption capacity of Cu (II) ions on NB has increased with increasing pH, adsorbent amount and temperature. The Langmuir adsorption isotherm properly describes the equilibrium adsorption and the maximum adsorption capacit...

Toxicological and …, 1994

Page 1. Toxicological and Environmental Chemisiry, Vol. 43, pp. 141-145 © 1994 Gordon and Breach ... more Page 1. Toxicological and Environmental Chemisiry, Vol. 43, pp. 141-145 © 1994 Gordon and Breach Science Publishers SA Reprints available directly from the publisher Printed in Malaysia Photocopying permitted by license ...