2024-03-28T18:35:07Z
https://ejchem.journals.ekb.eg/?_action=export&rf=summon&issue=936
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Industrial Scale Production of Palm Super Olein using Modified and Innovative Dry Fractionation Technique
Hanafy
Hashem
Nasser
Abd- Ellh
Ghareeb
Abd-Eltawab
Adel G.
Abdel-Razek
Palm oil is vastly utilized in food processing, principally attributed to the physical and chemical characteristics that make it especially suitable for many food applications. The present work aimed to make attempts at finding a method for producing a novel palm super olein (PSO) through a new modified industrial application process. Pure and modified palm olein (palm olein + 5% palm oil) with an iodine value of 56.5 and 56.4 respectively were crystallized with a controlled cooling system and convenient stirring process. The slurry was then fractionated by dry fractionation either by conventional method at 17⁰C or by innovative method at 16.6⁰C. By varying the fractionation conditions used, a range of super olein and palm-mid fractions with different chemical and physical properties could be obtained. The Rancimat method was utilized to determine the oxidative stability of various palm oil fractions. Also, the physical and the chemical parameters of the different fractions were evaluated, whereas fatty acid composition was determined by GLC. The obtained PSO by fractionation using modified olein at 16.6 ⁰C gave PSO with MP 9⁰C and also enhanced the cloud point, melting point and iodine value. It is recommended that the modified and innovative dry fractionation process, performed in large-scale, can be taken as a model for improving palm oil fractionation.
palm olein
Palm super olein
dry fractionation
palm-mid fractions
oxidative stability
2018
02
01
1
11
https://ejchem.journals.ekb.eg/article_5163_3b81dde4edfc6cef61c0cbc530967f9a.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Performance and Emissions Characteristics of Diesel Engine Running Using Biodiesel and Its Blends with Kerosene Compared to Regular Diesel
Ferial
Zaher
Mohammed
Gad
Increase of environmental problems and depletion of fossil fuels are the driving forces to promote biodiesel as an alternative fuel in diesel engines. In the present work, biodiesel was prepared by transesterification of waste cooking oil with methanol and its physical and chemical properties were measured and found to be within acceptable limits of standard specifications of regular diesel fuel. Performance and emissions characteristics of a diesel engine running using biodiesel (B100) and its blends with kerosene were then assessed and compared to those using regular diesel (D100). Two biodiesel blends of biodiesel with kerosene have been used in this study containing 25 and 50% by volume kerosene as (K25) and (K50), respectively. The used engine was a direct injection four stroke, four cylinders diesel engine and it was run at two engine speeds being 1250 rpm and 900 rpm. The results have shown that the composition of the exhaust gases of the engine running at both speeds was better using biodiesel instead of regular diesel and it has been improved further by blending biodiesel with kerosene. With respect to the brake thermal efficiency, it was found that the use of biodiesel instead of regular diesel reduced the thermal efficiency at 1250 rpm while the reverse was true at a lower running speed of 900 rpm. However at both engine speeds, the thermal efficiency can be improved by blending biodiesel with kerosene.
Waste Cooking Oil
transesterification
kerosene
performance
emission
2018
02
01
13
21
https://ejchem.journals.ekb.eg/article_5094_129054927b072044cd3bfaf16802b086.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
High-Performance of Nanoparticles and Their Effects on The Mechanical, Thermal Stability and UV-Shielding Properties of PMMA Nanocomposites
Hesham
Moustafa
Darwish
Darwish
Ahmed
Youssef
Sameh
Reda
Abdelaziz
El-Wakil
The target of this work is to choose a suitable nanoparticle for preparing a highly ultraviolet (UV)-shielding from poly (methylmethacrylate)(PMMA) nanocomposites at low concentration and to decrease the destructive effects of UV radiation. Morphologies of the synthesized nanoparticles were investigated by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM). Whereas, pure PMMA and its nanocomposites were characterized by using dynamic mechanical analysis (DMA), tensile testing, UV-visible spectra (T%), and thermogravimetric analysis (TGA). The obtained results showed a good correlation between the tensile properties, DMA and TG analysis depending on the type of nanoparticles used in the PMMA matrix, especially in case of ZrO2 and ZnO. Furthermore, UV-vis spectra were analyzed ranging from 200 nm to 800 nm. It showed that UV radiation is significantly blocked from 100% to 0.2 % in the UV range between 200 nm and 360 nm for pure PMMA and to 0.08 % for PMMA/CeO2 nanocomposite and to 0.01 % for PMMA/CeO2 with various types of nanoparticles. After 360 nm, pure PMMA and PMMA/CeO2 were a little bit affected by UV lights, whereas the PMMA based on different nanoparticles was not affected. This result demonstrates that these nanocomposites could be strongly candidates for the sunscreens or for several fields that related to the UV photodegradation effects.
Nanoparticles
PMMA nanocomposites
X-Ray Diffraction
UV-visible spectra
Tensile Properties
thermogravimetric analysis
2018
02
01
23
32
https://ejchem.journals.ekb.eg/article_4439_83b6593b6e7bac9fed1d5c9b0e1abb20.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Study the Effect of a Polymerizable Surfactant on the Physico‒Mechanical Properties of Natural Rubber (NR) and Styrene Butadiene Rubber (SBR)
Doaa
El-Nashar
Aman
Khalaf
A.M.
Naser
H.
Abdel-Wahhab
Ayman
Ellaban
Polymerizable surfactant (methoxy polyethylene glycol methacrylate) (MPM) was synthesized by direct esterification reaction between (methoxy polyethylene glycol) and methacrylic acid and characterized by FTIR spectroscopy and proton nuclear magnetic resonance (1H NMR) spectroscopy. MPM was incorporated natural rubber (NR) and styrene butadiene rubber (SBR) and inspected as antioxidants for mixes vulcanizates to raise their resistant for ageing through storage to increase shelf life time. As well as possible to compare the effect of investigated (methoxy polyethylene glycol methacrylate) (MPM) with the commercial applied antioxidant in the production of rubber, as (2,2,4-trimethyl-1,2-dihydroquinoline[TMQ]. The rheometric and physico mechanical properties of rubber mixes after and before thermal ageing were measured. The results obtained revealed that 1 and 1.5 methoxy polyethylene glycol methacrylate (MPM) parts per 100 of rubber (phr) have superior effect in the protection of NR and SBR vulcanizates respectively.
Polymerizable surfactant
natural rubber
synthetic rubber
antioxidant
Ageing
physico - mechanical properties
2018
02
01
33
44
https://ejchem.journals.ekb.eg/article_5200_34882f7b25a39e0748e000286d392d25.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Biocidal Activity and Corrosion Inhibition of Some Cationic Surfactants Derived from Thiol Polyurethane
Mohammed
Zaky
Ibrahim
Sabbah
Nabil
Negm
Mostafa
Hendawy
Six series of cationic polyurethane surfactants [PQ10-20] were synthesized by the reaction between different six esters (which prepared by condensation of fatty alcohol namely: octanol, decanol, dodecanol, tetradecanol, hexadecanol and octadecanol with bromoacetic acid) and polyurethane as quaternizing agent. The chemical structures of these surfactants were confirmed using elemental analysis, FTIR spectra,+HNMR and UV analysis. The surface activities of the synthesized cationic thiol polyurethane surfactants showed their tendency towards adsorption at the air/water interface. The adsorption tendency was estimated from the values of surface tension and the depression of surface tension at the critical micelle concentration. The studied surfactants were evaluated as antimicrobial agents against pathogenic and sulfur reducing bacteria using inhibition zone diameters and minimum inhibition concentration values. The synthesized cationic thiol polyurethane surfactants showed good antimicrobial activities against the tested microorganisms including Gram positive, Gram negative as well as fungi. The synthesized compounds were tested for the activity as corrosion inhibitors against carbon steel corrosion in 2N H2SO4 at 50, 100, 200, 400 and 600 ppm. The inhibition efficiencies of the tested compounds showed good inhibition and protection of the carbon steel. The corrosion inhibition tendency correlated to the surface activity and chemical structure of the compounds.
cationic surfactants
Surface activity
Adsorption
antimicrobial activity
Corrosion inhibition
polyurethane
2018
02
01
45
60
https://ejchem.journals.ekb.eg/article_4704_ddde25ec24c1d4db8168219490cbc829.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Preparation and Characterization of Poly Dimethylsiloxane Based on Polyurethane Hydrogels with Interpenetrating Network Structure for Contact Lenses Uses
Fahima
Helaly
Sanaa
El Sawy
Ahmad
Hashem
Reda
Mourad
The interpenetrating polymer network (IPN) silicone hydrogels have been synthesized using polydimethylsiloxane- polyurethane- polyethylene glycol methacrylate (PDMS–PU–PEGMA) prepolymer with different concentrations of N,N dimethyl acrylamide (DMA), polyethylene glycol methacrylate (PEGMA) and methacryloxypropyl tris(trimethylsoloxy)silane (TRIS) by UV initiated polymerization process in the presence of free radical photoinitiator. The physicomechanical and chemical properties of the IPN silicone hydrogels, as water content, protein resistance, contact angle, optical transparency and mechanical properties were evaluated. The results revealed that DMA and PEGMA incorporated in IPN silicone hydrogel improves the hydrophilicity of silicone hydrogel with higher optical transparency and better protein resistance ability. The moduli of IPN silicone hydrogels indicate stiffer network as the concentration of PDMS–PU–PEGMA prepolymer increased. IPN silicone hydrogels belong to hydrophilic surfaces with the lowest water contact angle of 48.76o.
Interpenetrating polymer network
silicone hydrogels
polydimethylsiloxane- polyurethane
contact lenses
2018
02
01
61
74
https://ejchem.journals.ekb.eg/article_5162_d65f711d059fc0b1ae15c39b61e68eaf.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Carbon Nanotubes as Superior Sorbent for Removal of Phenol from Industrial Waste Water
Carmen
Elshafiee
Mohamed
Abdel-salam
Sayed
Moalla
Hager
Ali
Doaa
Osman
Renee
Abdalla
Yasser
Moustafa
Organic pollutant substances have direct effect on humans and animals. Wastewater containing organic pollutant like phenol compound can contaminate ground water resource and thus lead to a serious ground water problem. This study present the adsorption technique of (MWCNTs) which is used as adsorbents for the removal of phenol compounds from synthetic contaminated water. Many parameters are studied like pH, agitation speed, contact time and adsorbent concentration to determine their influence on the removal of phenol and on adsorption rate .The concentration of phenol in water before and after treatment was determined (analyzed) using high performance liquid chromatography technique (HPLC).The kinetic studies for adsorption followed the pseudo-second order model. The adsorption isotherm fit with Langmuir isotherm. The optimum conditions using MWCNTs were contact time 120 min, pH 7, agitation speed 130 rpm and dose of adsorbent 0.3 g. The removal percentage was 85.54%.
carbon nanotubes
adsorbent materials
Phenolic compounds
industrial waste water
agitation
kinetic adsorption
2018
02
01
75
84
https://ejchem.journals.ekb.eg/article_4387_f2fddf79d5d6af8de44eb78e75c9c1c8.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Micro-encapsulation of Eugenia supra-auxillaris phenolics Rich Fraction for Its Possible Use as a Natural Food Preservative
Hoda
Elsayed
Heba
Salama
Kawther
Elshafei
Nesrine
Hegazi
Eugenia supra-auxillaris (family Myrtaceae) leaves were explored for their total phenolic content and antimicrobial activity against some food borne pathogens for its probable use as a food preservative. The total extract of E. supra-auxillaris exhibited significant antimicrobial activity against Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa and Aspergillus niger at concentration of 100 mg/ml. Upon fractionation, the ethyl acetate fraction appeared to be more potent than the n-butanol fraction in inhibiting bacterial and fungal growth and had higher polyphenolic content. Three phenolic compounds were isolated and identified from the bioactive fraction. The impact of microencapsulation of the ethyl acetate fraction with sodium alginate (2%) was investigated. The micro-encapsulated fraction retained its antimicrobial activity as low as a concentration of 25 mg/ml. Since the tested pathogens are frequent candidates causing food-borne illnesses, it would be interesting to investigate the potentiality of their possible application in food to increase shelf life or promote safety.
Eugenia supra-auxillaris
Phenolics
micro-encapsulation
anti-microbial
Sodium alginate
2018
02
01
85
91
https://ejchem.journals.ekb.eg/article_4740_112fcb18ecd04b195e843c4e4f8c35a4.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Production of Vitamin B12 and Folate Using a Potent Mutant Strain of Klebsiella pneumonia
Ibrahim
Abdelsalam
Abstract The production of vitamin B12 and folate under solid state fermentation was investigated by using different mutants of klebsiella penumonia. The results showed that the isolate no ( EM33TE) produce the maximum B12 and folate yields ( 77.45 and 88.22 ug/ml) respectively. The supplementation of the fermentation medium by different carbon sources (glucose, fructose, mannose, sucrose, maltose, lactose ,starch and dextrin) indicated that the best carbon source was glucose and the maximum B12 yield (356.9ug/ml) was obtained by the sequential addition of glucose(10g ) to the fermentation medium . PCR studies revealed that clear differences at bands number and size between the original strain and its mutants using RAPD analysis by three different random primers, these differences in RAPD profiles confirmed the evidence of genetic variations of mutants and K.pneumonia genome after EMS-mutagenesis
Keywords: Vitamin B12
folate
EMS-mutagenesis
Solid state fermentation
RAPD analysis
2018
02
01
93
100
https://ejchem.journals.ekb.eg/article_4831_bba6e4085eadfecc37a965a521e9647f.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Tamarix aphylla Biomass as Efficient Adsorbent for Removal of Pb(II) Ions from Aqueous Solution: Kinetic and Applicability for Different Isotherm Models
Magdy
Madbouly
A.
Al-Anwar
Tamarix aphylla biomass (TAB) is a low cost adsorbent that has been used for the removal of Pb (II) ions from an aqueous solution. It was characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) to support the adsorption of Pb (II) ions. The ability of TAB to adsorb Pb (II) ions was investigated by using batch adsorption procedure. The effects of various parameters such as solution pH, adsorbent concentration, contact time and initial Pb (II) ions concentration were examined. The adsorbent data were analyzed using two, three, four and five parameter models at 30oC by using nonlinear regression analysis. Various kinetics models including the Pseudo-first-order, Pseudo-second-order, Elovich, Intra-particle diffusion and Bangham models have been applied to the experimental data to predict the adsorption mechanism. It was found that pseudo-second-order rate was better obeyed than pseudo-first-order reaction supporting that chemisorption process was involved. The examination of error analysis methods showed that the Langmuir model provide the best fit for experimental data than other isotherms. The obtained results show that TAB can be used as an effective and a natural low-cost adsorbent for the removal of Pb (II) ions from aqueous solutions.
Tamarix aphylla
Pb(II) ions
Adsorption
aqueous solution
Isotherm models
Adsorption kinetics
2018
02
01
101
119
https://ejchem.journals.ekb.eg/article_5176_e94bd52a7d476f7015b17ffe8ade8a89.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Highly Sensitive Eu3+ Doped in Sol-Gel Matrix Optical Sensor for The Assessment of Ciprofloxacin in Different Real Samples
Mohamed
Attia
A.
Youssef
Ahmed
Mohamed Ismael
Ramy
Gaafar
Asmaa
Adel
Ahmed
Twfik
Ahmed
Wafaey
Hesham
Gamal El-Din Afify
Ahmed
Sayed Abozaid
The efficiency of excited-state interaction between Eu3+ doped in sol- gel matrix and the industrial product ciprofloxacin of (CFX) has been studied in different solvent and pHs. A high luminescence intensity peak at 617 nm of europium- ciprofloxacin complex at λex=365 nm in acetonitrile was obtained. The photophysical properties of the red emissive Eu3+ complex doped in sol-gel matrix have been elucidated, the europium was used as optical sensor for the assessment of ciprofloxacin in the pharmaceutical tablets and serum samples at pH 8.0 and λex = 365 nm with a concentration range of 5.0 ×10−9 - 1.0 ×10−6 mol L−1 for ciprofloxacin, correlation coefficient of 0.99 and detection limit of 1.65 ×10−9 mol L−1.
ciprofloxacin
Europium (III)
enhancing
Luminescence
Optical Sensor
sol-gel
2018
02
01
121
129
https://ejchem.journals.ekb.eg/article_4440_68a74ff11255957ba87f6ea95d202d31.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Application of Some Physical Techniques for Forensic Discrimination of Printer Toner
Samia
Shraa
Yasser
Moustafa
Al-Sayed
Bakr
Abdel Aleem
Abo Elmagd
Ibrahim
Abd El-Aziz
The documents examiner had trouble forensic discrimination between types of toner using a single analysis method. In our study seven samples of toner removes from laser printers of various and same brands of different models will be analysed using more than one method as Fourier transform infrared (FT-IR), Raman spectroscopy, X-ray fluorescence (XRF) and X-ray diffraction (XRD) to distinguish between different toner samples and applying all analysis data for forensic evidence. Results of FT-IR analysis show that all toner samples of HP brand had the same polymeric resin. Raman spectroscopy used to differentiate between toner samples had the same polymeric resin in FT-IR analysis by comparing their Raman spectrum. Toner samples of HP 2300 and HP 4700 printers were indistinguishable by using results of FT-IR and Raman spectroscopy, therefore, more elemental analysis will be required. XRF used to differentiate between indistinguishable toner samples of HP 2300 and HP 4700 printers by FT-IR and Raman spectroscopy. Also for all toner samples, results of XRF shown that iron, silicon, cupper, calcium, and ruthenium were the major percent elements present in toner. The results of XRD show that there are common compounds (phases) between the analyzed toner samples and the composition for major elements present were oxides.
Toner analysis
Laser printer
Raman spectroscopy
FT-IR
XRF
XRD
Forensic discrimination
2018
02
01
131
142
https://ejchem.journals.ekb.eg/article_4495_f88fca5c4c33413ebe68d2a99b98d7ad.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Spectrophotometric Microdetermination of Tretinoin, Isotretinoinusing Iodine and Tazarotene Microdetermination Via Reaction with Rose-Bengal Reagent
Mohamed
Zayed
Marwa
Abdel Basset
THE reactions of Iodine or Rose-Bengal (Rbng) reagents with three of retinoid drugs Tretinoin (Tret), Isotretinoin (Itret) and Tazarotene (Taz) had been studied for the development of simple, rapid, sensitive spectrophotometric methods for micro-determining of these drugs in pure and in their pharmaceutical formulation. These methods are based on the formation of reaction product between the drugs and iodine or rose -bengal reagent. The spectra of the formed reaction products were measured at selected proper conditions of time, temperature, pH and selected wavelength. The analytical parameters such as standard deviation (SD), relative standard deviation (RSD), Sandell’s sensitivity (S), LOQ and LOD were calculated in order to check accuracy, sensitivity and precision of the given procedures. The values of SD = 0.1312 - 1.100, RSD = 0.5556 - 1.946 %, S = 0.0229 – 0.0508 μg cm-2, LOQ = 13.17 – 17.45 μg mL-1, LOD = 4.347 – 5.757 μg mL-1 obtained of these parameters refer to the accuracy and sensitivity of the suggested procedures and can be applied for analyses of these drugs in their pharmaceutical formulations. Beer's law was valid in the range 9.041 – 29.71, 35.75 – 119.6 and 10.48 – 71.11 μg mL-1 with recovery of (97.84 - 102.8 %), (98.67 - 101.8 %), (98.32 - 102.0 %) for Tretinoin, Isotretinoin and Tazarotene respectively, The importance of this research stems from applications of these retinoid derivatives in skin improvements. They are always used as creams and found to be effective for photo-damage and for protection from skin irritation. Therefore, the proposed methods had been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. The results obtained were found to be in good agreement with those obtained by official methods. This evaluation had been done by F- and t- tests
Keywords: Tretinoin
Isotretinoin
Tazarotene
Iodine
Rose- Bengal and Spectrophotometry
2018
02
01
143
153
https://ejchem.journals.ekb.eg/article_4386_c4142219cb5025a989a2c6cb389dce32.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Up-grading of Locally Produced Metallurgical Grade Silicon (MG-Si)
Heba
Ali
Mohamed
El-Sadek
Mohamed
Morsi
Kamilia
El-Barawy
Rabab
Abou-Shahba
Locally produced metallurgical grade silicon (MG-Si ~ 97%) was upgraded by using wet-milling process. This is including milling of MG-Si in presence of 2M HCl solution for different time periods up to 60 min. The effect of milling time in HCl solution was studied. Soaking of the milled products (at optimum milling time 15 min) with continuous stirring in the same solution of 2M HCl for interval time up to 240 min also were investigated. Finally, the effect of addition of 2M HF to the milled product was discussed. The leached samples were investigated by X-ray fluorescence (XRF), and scanning electron microscope (SEM). It was found that, 99.92% purity of MG-Si was achieved after 15 min milling time with 2M HCl followed by addition 2M HF for 240 min with continuous stirring. About 97 % removal efficiency of the impurities was obtained.
MG-Si
up-grading of MG-silicon
purification of silicon
acid leaching
2018
02
01
155
161
https://ejchem.journals.ekb.eg/article_4708_5443e3a141955dd69a20ce7ac4affef3.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Processing, Characterization and Application of Some Borophosphate Glasses Containing Antibacterial and Antifungal Oxides in Bioactive Demands
Mona
Ouis
Amira
Fayad
Abeer A.
Abd El Aty
Gehan T.
El-Bassyouni
A series of borophosphate glasses doped individually with few antibacterial oxides; CeO2, ZnO and CuO were prepared by melt quenching technique. The structure and bioactivity of the prepared samples were analyzed through FTIR spectral technique and corrosion behavior before and after immersion for 2 weeks in simulated body fluid (SBF) under static condition. Microstructure of the glass was examined using SEM to confirm the bioactivity of glass through the formation of calcium phosphate (CaP) layer on the surface. FTIR spectra of the glass after immersion in SBF show characteristic peaks of calcium phosphate. Weight loss% display a difference in solubility in the SBF solution in relation to the antibacterial oxide added. SEM results show clear nodular microcrystalline calcium phosphate. The prepared glasses revealed effect against some microbes and bacteria. It was established that the addition of the antibacterial oxides had a positive effect on the glass bioactivity and may find a part in biomedical applications.
Borophosphate glasses
Bioactivity
FTIR
SEM
antibacterial-antifungal glass
2018
02
01
163
173
https://ejchem.journals.ekb.eg/article_5026_e6ed7773bc4f35e7aa56545f6e444086.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Fabrication of Commercial Nanoporous Alumina by Low Voltage Anodizing
Ashraf
El-Shamy
The present work is considered as an introductory study on the procurement of membranes from nanoporous alumina through one-step anodization. The nonporous alumina was obtained by anodizing the specimens at low voltage 5V for 20 minutes in phosphoric acid. The self-ordered porous arrangements can be acquired by using this process. The variables of space between pores, high pore density on the alumina surface are subjected to comparison with membranes which obtained by other methods. The mixture of phosphoric acid and chromium trioxide is used for removing the formed aluminum oxide after the first anodization. The self-ordered porous configuration is obtained at the second anodization step at the same conditions of the first anodization process. The nonporous alumina membrane was subjected to characterization of its surface morphology by scanning electron microscopy SEM and the electric properties were examined by using the electrochemical impedance test EIS. The formed nanoporous structures can be used for fabrication of sensor elements.
Porous alumina
Anodization
Nanostructures
Nanopore
Self-organization
2018
02
01
175
185
https://ejchem.journals.ekb.eg/article_4792_4b03a2d7a36e632d4ad8a99109194264.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Enhance the Quality of Cellulosic Fibers Produced from Agricultural Wastes through Flocculation Using Chitosan
Samar
Mohamed
Zenat
Nagieb
Mona
Abd El Sabour
Paper sheets were prepared by using different types of cellulosic fibers produced from agricultural wastes. Chitosan solutions with different concentrations were added to surface of paper sheets. Mechanical properties enhanced in case of treated paper sheets with chitosan comparing with untreated. Generally in all cases of paper sheets obtained from different pulps, the strength properties reached their optimum enhancement in presence of 0.5% chitosan solution almost. Optical properties enhanced by addition of chitosan. Paper sheets obtained from unbleached bagasse treated with chitosan gave the best results compared with that obtained from the others. Also paper sheets obtained from unbleached rice straw and that obtained from unbleached mixed (rice straw and 25% bagasse) gave impressive results. Crystallinity index from the ratio A 1435cm-1/ A 900 cm-1 in infra-red spectra and X-ray diffractometry proved all the above where X-ray data showed that treated paper sheets was accompanied by a significant increase in the fraction of crystalline polymer compared with untreated. It was observed from the morphology of fibers that fibers of the sized paper enhanced and became tight and smooth.
Paper sheets
Chitosan
X-Ray Diffraction
Optical properties
Mechanical Properties
2018
02
01
187
196
https://ejchem.journals.ekb.eg/article_4703_77a39e1db97f057e3821255f002aec38.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Synthesis and Study Antimicrobial Activities of Some Novel Tetrazole Derivatives
Maher
Nessim
Safaa I.
Elewa
Manal G.
Mohamed
Four (2-phenol derivatives) were coupled with 1H-tetrazole-5-diazonium chloride to synthesize four new compounds namely Ta-d. These prepared Azophenols reacted with two 4-alkoxy acids (8 and 10) to form two new series of 4-((1H-tetrazol-5-yl) diazenyl)-2-(R)-phenyl-4-(octyloxy) benzoates T8a-d and 4-((1H-tetrazol-5-yl)diazenyl)-2-(R)-phenyl-4-(decyloxy) benzoates T10a-d respectively. The structures of the twelve synthesized compounds were confirmed using the conventional tools of analysis, Elemental Analysis, FT-IR and 1H-NMR spectroscopy. They were tested as anti-fungi and anti-bacteria. Most of the prepared compounds possessed good antimicrobial action for Gram Positive and Gram-Negative Bacteria, whereas they gave no action on Aspergillus Fumigatus or Candida albicans.
Tetrazoles
Diazotization
phenols
1H-NMR
Biological Activity
2018
02
01
197
206
https://ejchem.journals.ekb.eg/article_5025_ea403e1f94e75a8e03c8db5e230fc860.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Cyanoacetyl urea in heterocyclic synthesis part V: Facile synthesis of poly-functionalized pyrimdines via different behaviors of its free urea amino group
Hoda
Othman
Maher
Al-Hashash
Galal
Nawwar
The poly-functional precursor, cyano-acetyl urea, could be utilized in the synthesis of various pyrimidens utilizing its benzothiazole derivative 1. The free amino group in 1 undergoes different chemical behavior according to the reaction conditions to afford pyrimidines 3,4,5,6,7a,b and 9a,b, respectively.
1
3-Benzothiazole
Pyrimidine
Cyanoacetyl urea
small molecules
2018
02
01
207
212
https://ejchem.journals.ekb.eg/article_5093_3cffb52308afdf3f2e85b1ba877a223b.pdf
Egyptian Journal of Chemistry
Egypt. J. Chem.
0449-2285
0449-2285
2018
61
1
Effect of KF Modification to Kaolinite Catalytic Activity in Microwave-Assisted Biodiesel Conversion
Is
Fatimah
Dwiarso
Rubiyanto
ptian
Yudha
Preparation of reusable catalyst based on KF-modified kaolinite clay for reusable catalyst application on biodiesel conversion has been investigated. Materials preparation were carried out by simple mixing and solid reaction between KF and kaolinite at various KF loading. The effect of KF content loaded the surface structure and surface basicity have been studied. Characterization of the materials was investigated based on scanning electrone microscopy-energy dispersive-x ray spectroscopy (SEM-EDX) SEM, x-ray diffraction (XRD) and gas sorption analysis. Increasing the reusability and the effectivity of catalysts utilization was studied by comparing reflux method and microwave (MW)-assisted reaction of biodiesel production from Jatropha oil. Results showed that increasing solid basicity is the character plays important role for increasing catalytic activity in biodiesel conversion. By comparing the reaction method, it is found that similar biodiesel yield was obtained with shorter time, higher turnover frequency (TOF) and better reusability over MW assisted-method.
Biodiesel
clay
Kaolinite
microwave
KF-modified clay
2018
02
01
213
223
https://ejchem.journals.ekb.eg/article_5242_3d55dd9598116518c16e3cef2757b83a.pdf