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Preliminary Study of Alkali Activation of Basalt: Effect of NaOH Concentration on Geopolymerization of Basalt

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Journal of Materials Science and Chemical Engineering 2017年第11期5卷 58-76页

作者： mohamed El-Shahte ismaiel Saraya Ezzat El-Fadaly Department of Chemistry Faculty of Science Al-Azhar University Cairo Egypt Environmental Studies and Research Institute Sadat City University Sadat City Egypt

The main objective of this study is to examine the possibility of using fresh basalt powder in the preparation of geopolymer pastes. Four NaOH concentrations of 2.5, 5, 7.5 and 10 M were used to alkali activation of basalt. In addition, effect of curing temperature at ambient, 45°C and 65°C were studied. The geopolymer pastes were investigated using FTIR, XRD and SEM-EDS techniques as well as compressive strength up to 90 days. The results were shown the compressive strength of prepared geopolymer increased with concentration of alkali activator up to 90 days. On the other hand, the compressive strength of prepared geopolymer pastes were improved with increased curing temperature. The results showed that there was a change in the chemical and mineral structure, due to the reaction of the sodium hydroxide with the different minerals of the basalt. In addition, the Na/Al and Si/Al ratios were completely different from that of the raw basalt. The geopolymerization reactions occurred at the surface basalt and the unreacted basalt particles actually play a supporting role in the geopolymer properties.

关键词： Fresh Basalt Alkali Activation Geopolymer FTIR XRD EDS-SEM

Influence of Nano-Barium Sulfate Agglomeration on Microstructure and Properties of the Hardened Cement-Based Materials

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Journal of Materials Science and Chemical Engineering 2015年第11期3卷 72-81页

作者： mohamed El-Shahate ismaiel Saraya Inas Mostafa Bakr Department of Chemistry Faculty of Science Al-Azhar University Cairo Egypt Faculty of Engineering Mattareya Helwan University Cairo Egypt

The aim of the present work is to study the effect of Nano-barium sulfate additions on the physic-mechanical properties of hardened cement pastes. Nano-barium sulfate was prepared by the precipitation method. Eight mixes of filled cement pastes containing 0.5 wt%, 1.0 wt%, 1.5 wt% and 2.0 wt% of both nano-barium sulfate and micro-limestone were prepared and compared to the base OPC. The hydration characteristics were evaluated by the measure of combined water content, bulk density, total porosity and compressive strength for samples hydrated up to 90 days. The progress of hydration reactions was followed up by XRD analysis. The morphology and microstructure were studied by SEM. Nano-size barium sulfate acted as a nucleating agent and enhanced the hydration of cement pastes up to 2.0% mass content. Also, the microstructure was improved considerably. Accordingly, nano-size barium sulfate can be used successfully in the preparation of filled cement.

关键词： Nano-Barium Sulfate Cement Paste Filler Compressive Strength Microstructure

Formation and Stabilization of Vaterite Calcium Carbonate by Using Natural Polysaccharide

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Advances in Nanoparticles 2017年第4期6卷 158-182页

作者： mohamed El-Shahate ismaiel Saraya Hanaa Hassan Abd El-Latif Rokbaa Chemistry Department Faculty of Science Al-Azhar University Cairo Egypt Chemistry Department Faculty of Science and Arts Al-Baha University Al Makhwah Saudi Arabia Chemistry Department Faculty of Science Halwan University Cairo Egypt

This paper aimed to study the effects of natural polysaccharide (gum arabic, GA) on the formation of vaterite calcium carbonate and its stability in aqueous solution. Gum arabic is a macromolecule that has a high molecular weight and is amphoteric in character. A 0, 2.5, 5 or 10 ml of GA solution (30%) was added to the calcium chloride solution with various initial concentrations to prepare the vaterite calcium carbonate. The calcium carbonate particles were characterized using FTIR, XRD, SEM, TEM and DSC-TG as well as calculation of phase contents. The results of XRD and FTIR analysis were showing that the presence of GA during the precipitation changes the behavior of calcium carbonate to form vaterite until at lower dose used. In addition, the molar content of vaterite increased at the expense of content of calcite with increasing the GA dose. There are slightly improvements in the vaterite content by increasing the initial concentration. The formed vaterite calcium carbonates composed of aggregates as broccoli-like or spherical shape and with particle size 1.6 - 2.5 μm in diameter. TEM images showed that these aggregates composed of the sub spherical unit with diameter 15 - 30 nm. The thermal behavior of prepared vaterite was conformed the mineral composition of these phases. The prepared calcium carbonate, which is formed in the presence of different doses of gum, has a stability in the aqueous solutions at different temperatures, as the analyzes indicated that a very small percentage of the vaterite were converted to calcite. The gum arabic prevented or depressed the transformation of vaterite to calcite through capped the surface of particles, i.e. it is more effective in stabilizing the vaterite phase with increasing in initial concentration and time.

关键词： Gum Arabic Vaterite Characterization Nanoparticles Stability

Sol-Gel γ-Al₂O₃ Nanoparticles Assessment of the Removal of Eosin Yellow Using: Adsorption, Kinetic and Thermodynamic Parameters

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Journal of Encapsulation and Adsorption Sciences 2016年第3期6卷 70-90页

作者： mohamed S. Thabet Ahmed M. ismaiel Department of Chemistry Faculty of Science Al-Azhar University Cairo Egypt Department of Chemistry Faculty of Science Jazan University Jazan Saudi Arabia

The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al2O3 nanoparticles in batch technique was studied. γ-Al2O3 NPs was prepared and characterized by SEM, TEM, XRD and FTIR analysis. The effect of pH, dosage of adsorbent, contact time, temperature, and the initial concentration of dye was investigated. The maximum amount of dye removal found about 99.36% at pH4, the adsorption dose 1g/L, with the initial dye concentration of 100 mg/L, and the temperature of 25°C, with contact time 120 min. The adsorption behavior of the eosin yellow dye is applicable to Langmuir isotherm model, with the maximum sorption capacity of 47.78 mg/g of γ-Al2O3. The kinetic data also described by the pseudo-second-order model with a correlation coefficient (0.9999), and the mechanism of the process showed a multi-linear steps and the intra-particle diffusion was not only rate controlling step. The adsorption process was endothermic with positive enthalpy of 121.8 kJ/mol, and showed spontaneous process with a mean free energy -5.19 kJ/mol, and increase randomness, 369.77 J/mol. k, at the adsorbent solution interface. The adsorption process was chemisorption in nature The activation energy estimated from Arrhenius and modified Arrhenius is 40.9 kJ/mol, 106.37 kJ/mol respectively. The sticking probability of EY onto Al2O3 NPs very high estimated from the value of S* < 1, (4.82E-19).

关键词： Eosin Y Adsorption Nanoparticles Aluminum Oxide Thermodynamic Parameters Kinetics

Statistical Analyses and Geotechnical Evaluation of Nubia Sandstone, Golden Triangle Area, Egypt

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Journal of Geoscience and Environment Protection 2021年第11期9卷 46-60页

作者： Hesham Ahmed Hussein ismaiel mohamed mohamed Askalany Ali Ismail Ali Department of Geology Faculty of Science South Valley University Qena Egypt

Great efforts had been made to use indirect non-destructive tests in the geotechnical evaluation of rocks, especially sandstones, employing different empirical equations. However, most of these equations have been derived from hard and compacted sandstones data;therefore, the focus of this research is on weak and weakly compacted sandstones, aiming firstly to obtain empirical equations for estimating their characteristics, secondly to demonstrate and visualize the correlations between the studied variables, and finally to cluster the studied samples based on their characteristics. To attain these aims, twenty oriented block samples were collected from Nubia sandstone, central Eastern Desert, Golden Triangle area, Egypt. These samples were prepared and tested according to standard test methods, including uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), Schmidt rebound number (SRN), porosity (n), bulk density (ρ), and ultrasonic P-wave velocity (UPV). The loss on ignition (LOI) was also employed as a physicochemical test for classifying the studied samples and indicating pores filling materials. The results revealed that these sandstones are characterized mainly by high n, low ρ, and low UPV values and these give an indication of weakly compacted and weakly cemented sandstone with shallow burial diagenetic conditions. Based on UCS and elastic modulus values, these sandstones are mainly classified as very low strength and highly yielding rocks. The results of regression analysis show satisfactory correlations between physical and mechanical characteristics, indicating the suitability of obtained empirical equations to deduce these properties. Principal component analysis revealed that the LOI, BTS, SRN, and US

关键词： Geotechnical Evaluation Empirical Equations Statistical Analyses Nubia Sandstone Non-Destructive Test

Potentiometric Determination of Trace Amounts of Mercury (II) in Water Sample Using a New Modified Palm Shell Activated Carbon Paste Electrode Based on Kryptofix 5

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American Journal of Analytical Chemistry 2012年第12期3卷 859-865页

作者： Ahmed Abu ismaiel mohamed Kheireddine Aroua Rozita Yusoff Chemical Engineering Department University of MalayaKuala LumpurMalaysia

A new modified palm shell activated carbon paste electrode based on 1,13-Bis(8-quinolyl)-1,4,7,10,13-pentaoxat-ride-cane ,8,8-(1,4,7,10,13-Pentaoxatridecylene)-diquinoline (Kryptofix?5) and plasticizing agent was prepared and studied as Hg2+ selective electrode. The best performance was observed with the electrode composition having the iono-phore-palm shell activated carbon-plasticizer composition 10%:50%:40% with Nernstian response over the concentration range of 1.0 × 10–8 - 1.0 × 10–2 M with a slope of 42 ± 1.5 mV per decade of concentration. The detection limit as determined from the calibration plot is 1.0 × 10–7 M. The proposed electrode shows good selectivity for Hg(II) with interfering ions. The response time of the electrode is fast (≤10 s), and can be used in the pH range of 3 - 11. The electrode was used to determine mercury in drinking water.

关键词： Palm Shell Activated Carbon Kryptofix 5 Ion Selective Electrode Mercury

Geotechnical Evaluation of Sedimentary Rocks and Karstification Phenomena of Carbonates Exposed along New Upper Egypt-Red Sea Road, Eastern Desert, Egypt

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Journal of Earth Science and Engineering 2012年第11期2卷 636-647页

作者： Hesham A.H. ismaiel mohamed M. Badry Geology Department Faculty of Science South Valley University Qena 83523 Egypt Quality Control Sector Nasr General Contracting Company Cairo 2919 Egypt

Geotechnical properties of sedimentary rocks exposed along upper Egypt-Red Sea road were investigated to evaluate their geotechnical behavior. One of the most important aims of this work was to determine the engineering problems affected on the road due to the geotechnical behavior of the studied sedimentary rocks and to suggest the suitable solution. Specific weight, unconfined compressive strength, slaking durability and free swelling were measured. The results showed that the studied crystalline limestone, marly limestone and Issawia limestone had higher unconfined compressive strength values ranging from 34,184.00 kN/m2 to 42,602.00 kN/m2 and the studied shale, siltstone and coral reef had lower values ranging from 3,689.00 kN/m2 to 6,933.00 kN/m2. The results showed also that the studied shale, siltstone and mudstone had fast to very fast slaking rate and their slaking amount described as low to medium after Gamble＇s slake durability classification. Replacement and/or chemical stabilization （using lime and/or cement kiln dust） of the expansive sedimentary rocks （shale and mudstone） were recommended to reduce the swelling. Geophysical investigations including shallow seismic, microgravity and GPR （ground penetrating radar） were recommended to scan the sub-grade of the road at El Maaza plateau to determine possible other caves and large voids under the road to avoid its collapse.

关键词： Unconfined compressive strength free swelling karstification cave stalactites stalagmites.

Kinetic and Equilibrium Isotherms Studies of Adsorption of Pb(II) from Water onto Natural Adsorbent

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Journal of Environmental Protection 2014年第17期5卷 1667-1681页

作者： Taha M. Elmorsi Zeinhom H. mohamed Walied Shopak Ahmed M. ismaiel Chemistry Department Faculty of Science Jazan University Jazan KSA Chemistry Department Faculty of Science Al-Azhar University Cairo Egypt

In this research dobera leaves (DL), an agricultural waste, available in large quantity in south region of Saudi Arabia, were used as low-cost adsorbent for removal of metal ions such as Pb(II). Batch operation was used to study the equilibrium behavior of DL. The effects of initial concentration of Pb(II), solution pH, contact time and adsorbent dose were evaluated. To study the kinetics of adsorption of Pb(II) onto DL, pseudo-first-order, pseudo-second-order and intra-particle diffusion were used. Adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R2. Furthermore, to design the equilibrium data of adsorption of process, four adsorption isotherm models such as Langmuir, Freundlich Temkin and Dubinin-Radushkevich (D-R) were used. It is found that Langmuir equation has the highest value of R2 (0.999) compared with other models. In presences of a mixture of Pb(II)/Ni(II), DL were found to be selective for Pb(II) ions with a high adsorptive capacity of 83 mg/g and show favorable adsorption with RL 90%) from drinking water with less competition of other ions present in water.

关键词： Dobera Leaves Pb(II) Adsorption Kinetics Adsorption Isotherms

Removal of Direct Dyes with Cement Kiln Dust

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材料科学与工程（中英文B版） 2011年第1期1卷 97-105页

作者： mohamed E1-Shahate ismaiel Saraya Mahmoud EI-Saied Aboul-Fetouh Hashaim Saied Nassar Aref mohamed Abd-E1-Rahman Department of chemistry Faculty of Science Al-Azhar University Nasr City Cairo Egypt Mubarak City for Scientific Research and Technological Applications New Borg El-Arab Alexandria Egypt

This paper aims to investigate removal of some direct dyes from aqueous solution using cement kiln dust, and monitoring the dye in colored cement kiln dust. Solution with 0.8 g/l concentration was treated with cement kiln dust until the color of dye disappears. The colored cement kiln residue was separate by filtration and dried on microwave oven. The concentration of dye was measured before and after treatment by UV-Vis spectroscopy as well as after washing of colored residue with water. Also, the colored residue was investigated with, XRD, IR and DSC techniques as well as measured the loss on ignition at 450 °C for 2 h. Obtained results showed that cement kiln dust has the power to remove all existing direct dyes and the residue has the same color of dye. When colored residue was washed with water, there was no back diffusion of dye in to water. This may be mainly due to chemical reaction that took place between cement kiln dust and dye. Thus analysis such as IR, XRD and DSC are in agreement with these results.

关键词：直接染料水泥窑灰粉尘紫外可见光谱浓度测定清水冲洗 X射线衍射 DSC技术