Papers by Author: Zahra Fakhroueian

Abstract: ZnO nanosphericals and nanorods have interesting potential applications in various fields such as antibacterial and enhanced oil recovery process. In this work, it was shown that 30 ml of a water-based solution containing 3% of ZnO nanofluids could significantly change the wettability of a carbonate reservoir rock from a strongly oil-wet alter to a strongly water-wet condition, after 3 days aging of the rock at 70°C in the designed solution. Moreover, we have studied air-water and oil-water interfacial tensions of system containing nanofluids. Fluids included ZnO nanoparticles and quantum dots nanostructures (QDOTs ZnO) could effectively decrease the n-decane/water interfacial tension and air/water surface tension. So their efficiency is much higher in comparison with distilled water.The stabilization of various aqueous ZnO nanostructured in mixtures of NaCl, CaCl₂, MgCl₂ and Na₂SO₄ salts were investigated, and 50000-163000 ppm transparent and stable nanosalt fluids were fabricated. Wettability of an oil-wet carbonate rock aged for 3 days at 70°C in the designed ZnO nanosalt fluids was studied by measuring the contact angles. The results show a strong change in wettability of carbonate rocks from oil-wet to more water-wet condition. These nanosalt fluids performed an excellent trend of surface tension and IFT reduction in comparison with distilled water too.

Abstract: Fine SiO₂ nanosphericals (2-5nm) and new various stable nanofluids including Tween 80, Span 80, Lauric alcohol-3EO, CTAB, SDS and K-Laurate surfactants in water or paraffin based solution were used as new SiO₂ nanoproducts in oil recovery. These nanofluids can strongly change oil-wet carbonate reservoir rock to complete water-wet wettability and showed an excellent trend of surface tension (S.T) and IFT (interfacial tension) reduction in comparison with pure water and reference solutions. The CaCO₃ plates reservoir was then aged for 2, 5 and 8 days into the 1, 3 and 8% of different concentrations of synthesized SiO₂ nanofluids (effect of various concentrations via different aging time). Air/water and n-decane/water contact angles on oil-wet and clean carbonate rock aged in designed SiO₂ nanofluids were measured and the pH value as a significant factor estimated. The interesting influence of microwave irradiation on surface tension and IFT including various SiO₂ nanofluids was investigated after 12 min which some of the especial nanofluid concentrations showed successful reduction. Our findings indicated the important effect of temperature over decreasing of surface tension and IFT between oil and water interface including SiO₂ nanofluids after annealing at 70°C. Therefore, this phenomenon can be significantly capable and valuable in applying of new technology in the fabrication of novel nanofluids in EOR processes and saving source of energy regarding to conventional production.

Abstract: This work investigates the effects of nanometric (5-8 nm) ZrO₂ nanoparticles on adsorption of two surfactants, SDS (sodium dodecyl sulfate) and C₁₂TAB (dodecyl trimethyl ammonium bromide) into oil/water, air/water and solid/water interfaces. Increasing the concentration of nanoparticles reduces the interfacial tension and surface tension of SDS at low surfactant concentration (< cmc) but it has a minor effect on interfacial and surface tension of C₁₂TAB. Repulsive columbic interactions between SDS molecules and nanoparticles can cause the higher adsorption of surfactant at the oil/water interface. Adsorption of both surfactants on carbonate rock increases by adding nanoparticles to the system. This possibly happened because of the formation of surfactant-nanoparticle negatively charged aggregates that tend to adsorb on positively charged surface layer of carbonate rock. ZrO₂ nanoparticles are surface active at the oil/water interface too, as the results of interfacial tension indicate they can decrease the n-heptane/water IFT about 14 units.

Abstract: This work was instigated by the fact that sol-gel chemistry provides a relatively simple way to incorporate recognition species in a stable host green environment. In this new strategy, which represents a low cost example of bottom-up nanoassembly, chemistry art is entering the field of nanobiotechnology in fabrication and control of an expanded homogeneous length of separate single-walled and ordered, helical lattice-like open-ended natural protein nanotubes (PNTs) and also creative novel bio-nanohybrids. A new type of protein nanohybrids containg nanotubes-nanorods, nanotubes-nanofibers, nanotubes core-shell nanofibers were prepared using an electrostatic self-assembly method with the aid of chemical partial hydrolysis of milk protein α-lactalbumin (sol-gel technique) at a suitable pH value for the first time. They can have long helically coiled length and are promising for high capacity drug loading and applying in nanomedicine as organ transplantation in human body and implant material, because of their improved stability and unique mechanical and lattice thermal resistivity properties. In this study, various valuable ligand or binding sites such as distinct Mn⁺², Ca⁺²or Zn⁺² cations were used for incorporated into protein nanostructures as the self-assembly essential stimulant motor. It was found that the designed nanobioproducts could retain and stabilize as very clear and transparent green aqueous nanobiofluids during two years.

Abstract: New nanofluids carrier containing fine homogeneous whey protein α-lactalbumin spherical nanoparticles and nanospheres have been synthesized by three methods in this research. Biochemical enzymatic catalysis by V8- protease, chemical hydrolysis (sol-gel assisted self assembly method) using cationic templates and metal ions ligand forming, and also by direct acidic titration method with applying various ethylene glycol derivatives containg alcohol solvents. Repeatability and stability of synthetic nanoparticles and nanospheres milk protein structures in clear and crystalline green water-based nanofluids was confirmed by dynamic light scattering (DLS) analysis and TEM images (2-5nm) even after a one year period of preparation. Fabrication of non-toxic nanosolutions-nanofluids including nonionic and cationic surfactants, cosurfactants and suitable solvents, besides proper incubation temperatures (37-50°C), adjusted aging times and doped of divalent ions–bridging (Ca2+, Mn2+ and Zn2+ ) between specific amino acids and carboxyl groups, are so vital factors in kinetically controlled self-assembly phenomenon of the natural protein building blocks to form high resistant and homogeneous nanoparticles and nanospheres in transparent and clear green nanofluids. Such nanofluids can have many applications in food and pharmaceutical industries for example in formulate foods with high nutritional value in oral and digestive (ingestion) routes, and drug delivery. Interesting textures of SEM images have also shown these new nanobiostructures of natural milk protein morphologies.

Abstract: The synthesis of nanostructures are very various, and the most of scientists always fabricate them by the coprecipitation method at pH = 10.5-11. If we prepare these nanocatalysts for partial oxidation of methane (POM), processes to transforme methane gas into hydrogen or synthesis gas (H2 + CO) for obtaining exact green fuel H2 gas at different pH, what will be occurring, and what is the influence of pH on nanoemulsion, nanofluids, nanostructures, and finally the application in syngas process In this study we prepared many different nanoparticles containing % x (w/w) Co, Ni, Ru and La oxides over the various supports e.g. Ce-ZrO2, MgO-CeO2, AlCeO2, SiO2, SiAl2O3, SiMgO, SiO2Al-MCM-41 nano mixed oxides sized (1-2 nm) at various pH (7, 8, 9, 11) by new coprecipitation and combine with nanofluids method using different direct agent surfactant, stabilizer, binder, alcohol solvent, dispersant and variable chemical pH controllers. The prepared nanostructures were characterized by common techniques such as SEM, TEM, XRD, Raman, FTIR, BET and TPR analysis at various pH. Also many marvellous and new mixture of nanotubes-nanoclay and nanotubes-nanocomposites with high % H2 selectivity and methane conversion were fabricated by CuOx and NiOx sputtering test followed coprecipitation method at pH 9, for POM reactions used in petrochemical industry for the first time.

Abstract: Processes to transform natural gas into hydrogen or synthesis of gas (H2+CO) have been extensively studied in recent decades. H2 can be used in fuel cells as a power source and syngas may be converted into hydrocarbons via the Fischer-Tropsch synthesis. An attractive alternative process for syngas production is the partial oxidation of methane (POM). The objective of this study is to find effective conditions in using of nanofine particles for producing high activity and novel nanocatalysts to syngas, especially selectivity green fuel H2 gas as a power source. Therefore, we could produce 98.6% methane conversion, and 97.1% H2 selectivity with the help of unique stable and new nanofine materials: Eco-friendly x%Ni / SiO2, Co /Ce/ZrO2, Ru / Ce / ZrO2, and highly active Co-Ru and Ni-Ru bimetallic over Ce-ZrO2 nanosized mixed oxide support catalysts. Recently, we prepared new and interesting nanostructures by Cu and Ni sputtering on the nanosized Ce-ZrO2 solid solution support in the first time. Several surfactants, dispersants and mixture of alcohol solvents were applied in synthesis of nanostructures and nanofluids as remarkable templates.