Sharif Digital Repository

In this thesis a smart anticorrosive pH-responsive coat was developed with layer by layer (LbL) technique in the assembly of SiO2/CTAB/PSS/HMTA/PSS/PEI/PSS. SiO2 nanoparticles were prepared from Matland Company (Iran) with average size of 24 nm. At first, the corrosion inhibition of HMTA for API 5L Grade B steel in 3.5 wt.% NaCl solution was investigated. Tafel polarization technique showed the optimum concentration of HMTA was 0.08 M with 92% corrosion inhibition efficiency as the morphology of coverage and adsorption on the steel surface was confirmed by SEM and EDS. AFM results showed the roughness of the surface decreased from 241 nm to 56 nm that is attributed to HMTA adsorption on the... 

The corrosion rate of steel (EN 10130 DC-04) in the presence of oleuropein in aqueous corrosive solutions (of different concentrations in 1M and 0.5M hydrochloric acid and also 3.5% sodium chloride) evaluated and results was shown that oleuropein can protect steel surfaces and it acts as good inhibitor. This means that the observations of linear polarization and weight loss experiments showed inhibitor efficiency more than 97% in acidic corrosive medium and above 74% for aqueous solution of 3.5% sodium chloride. Adding oleuropein at different concentrations (i.e. 300 ppm, 700 ppm, and 1000 ppm) to three different types of polymeric paint structures (nitrocellulose alkyd base, acrylic base,... 

In this study, the effects of different corrosion inhibitors on the corrosion of aluminum alloy which is used in the cooling systems of automotive industries were investigated. Also a comparison between the corrosion behaviour of the mentioned aluminum alloy with and without any galvanic connection to 5 different metals consist of solder, stainless steel, mild steel, brass and copper was done. The corrosion rate became more by establishing galvanic coupling. The base solution was ethylene glycol and water which is the base part of all antifreeze compounds. The tests were done at high temperature about 88ºC. Two different industrial corrosion inhibitors were examined in these conditions.... 

Many experimental and theoretical studies have suggested that zinc binding to Aβ could promote amyloid-β aggregation and reactive oxygen species (ROS) production induced by AD disease. Therefore, the introduction of multifunctional drugs capable of chelating zinc metal ion and inhibiting Aβ aggregation is a promising strategy in the development of AD treatment. In present study molecular docking and molecular dynamics (MD) simulations were used to evaluate the efficacy of two new bifunctional peptide drug, composed of two different domains: C-terminal hydrophobic region of Aβ and Zn2+ chelator region. To evaluate the multifunctionality of the ligands, a comprehensive set of MD simulations up... 

Alzheimer’s disease (AD) is the most common type of dementia in the elderly. The neuropathology and treatment of AD is not precisely determined yet, but according to the pathological studies, AD is associated with presence of toxic soluble oligomers and insoluble senile plaques formed by amyloidosis of Amyloid Beta (Aβ) in neocortical region of brain. An attractive therapeutic approach to treat AD is to identify small ligands that are capable of binding to critical residues in order to inhibit or reverse Aβ amyloidosis process as source of neurotoxicity. In this area, therapeutic efforts designed various organic agents and most of them focused on the N-terminal sequence of Aβ. The aim of... 

In this research project, the aim was to investigate the potential of olive leaf extract as an eco-friendly inhibitor for enhancing the corrosion resistance of reinforcing steel in simulated geopolymer concrete pore solution (GCP) containing chloride ions. The inhibitory effects of olive leaf extract were evaluated using various electrochemical techniques as well as scanning electron microscopy. The main phenolic compounds present in olive leaf extract were identified using high performance liquid chromatography (HPLC). Moreover, the elements and chemical bonds present in the surface passive film of the steel bar immersed in the olive leaf inhibiting system were characterized using... 

In this research, it has been tried to use alumina and magnesia nanoparticles to hydroxyapatite nano powder, a three-component coating, with corrosion resistance, adhesion and desirable biocompatibility on the 316 stainless steel substrate, by electrophoretic method. It should be applied at 3 voltages of 10, 30 and 50 volts and for 3 minutes. TEA was used as a dispersing agent and ethanol as a solvent to prepare the suspension. Alumina nano powder was added to nanohydroxyapat in two amounts of 10 and 20% by weight and 20% was optimized as the amount, and magnesia nano powder was added to the composition in three amounts of 1, 3 and 5% by weight, which was 3% by weight of the results Was... 

In this research, a coating was created on the steel surface using the network structure of zeolite imidazolate-8 (ZIF-8) and its effect on the corrosion behavior of steel was investigated. Then, the effect of two coupling agents, mercaptopropyltriethoxysilane (MPTES) and aminopropyltriethoxysilane (APTES) on the coating and its anti-corrosion properties was investigated. Then, in order to make a hydrophobic coating, the substrate was first coated with ZIF-8 and then a combination of silica nanoparticles plus hexamethyldisilazane (HMDS) and polymethylhydrogensiloxane (PMHS) was added to the initial solution and then coating was done. As a result of this process, the contact angle of water... 

In this project, olive leaf extract has been investigated as a green corrosion inhibitor or in other words environmentally friendly for rebars embedded in concrete in the Persian Gulf Sea water simulator. Olive leaves were prepared by ultrasonic method at 50 ° C with the help of ethanol solvent. The water-ethanol solvent was 70:30 and the resulting extract was immediately applied to the concrete mix in specified doses. Portland cement type 2 according to ISIRI-389-96 standard has been used to prepare concrete. The resulting extract powder was added to the samples in four different doses: 2%, 4%, 6%, 8% by weight of cement to prove the inhibitory function as well as the cathodic or inhibitory... 

In this study, the extract of Tragopogon buphthalmos Boiss was investigated as a green or environmentally friendly corrosion inhibitor for mild carbon steels in high concentration hydrochloric acid solutions. Tragopogon buphthalmos Boiss was extracted using the extraction method of digestion at 50 ° C assisted by ultrasonic bath. Water-ethanol-acetone solvents were used in ratios of 30:35:35, respectively. The ratio of plant volume to solvent volume was one to ten. The container containing the extract was placed in a bath water at 50 ° C until the extract was in the form of gum, then stored at -15 ° C In a freezer. Infrared Fourier transform spectroscopy (FTIR) was used to determine the... 

In this study, the effect of green coffee extract powder, as a green corrosion inhibitor of steel in a concrete simulation environment was investigated. In this study, the green coffee extract was obtained by the Maceration method and its performance was investigated by weight loss method, electrochemical methods including Polarization, Electrochemical Impedance Spectroscopy. Scanning Electron Microscopy images were also used to visualize the corroded areas. The results of the polarization test showed that 450 mg/lit of coffee extract powder at 25 °C has the corrosion inhibiting efficiency of about 82% and the corrosion rate of the bare sample reduced from 6 to 1.16 mpy. The dosage of 550... 

In this study, pitting corrosion of 304, 316 and 316L stainless steels in 3.5% NaCl solution at different temperatures (25, 40, and 70°C), were studied by electrochemical methods such as Cyclic Potentiodynamic Polarization, Electrochemical Impedance Spectroscopy and Immersion tests. Also, the effects of different concentrations of polyethyleneimine with two molecular weights (2000 and 60000 g/mol) on pitting corrosion of these steels were investigated. Finally, the adsorption behavior of inhibitors on surface of alloys was investigated by Atomic Force Microscopy (AFM) and Attenuated Total Reflectance Fourier transform spectroscopy (ATR-FTIR). It was found that both inhibitors prevent... 

Since the beginning of oil, gas and gas condensate production, the prediction of the formation of mineral scales in different operating conditions has been a serious challenge. Mineral scale are solid particles that are separated from the free water in the reservoir due to changes in the production conditions in terms of temperature and pressure or the fluid composition of the production fluid of reservoir, and there is a possibility of their deposing on the wall of the well column and in the production system, where The way of production from reservoirs faces serious risks. free water, which is permanently entering the pipeline, contains all kinds of salts in the structure of the fluid... 

Cellulose nanocrystals as a reinforcement in polymer nanocomposites are part of current research for reasons such as source renewable, biocompatibility, nanoscale dimensions, high specific surface area, and surface chemistry. This research used cellulose nanocrystals as a corrosion inhibitor carrier in epoxy-based composite with 1% by weight. In order to load the corrosion inhibitor, firstly, cellulose nanocrystals were surface modified by aniline so that they can spread well in the hydrophobic epoxy matrix. Different corrosion inhibitors were tested for adsorption on the surface of cellulose nanocrystals modified with polyaniline, but finally the acidic agent of phosphoric acid showed... 

In order to protect the corrosion of steel, a self-healing epoxy nanocomposite containing modified graphite carbon nitride (g-C3N4) and ZIF-67 was made along with benzotriazole (BTA) and cerium inhibitors. To increase the efficiency and also to increase the duration of use of inhibitors, it is better to load these inhibitors on containers such as MOFs. One of the useful MOFs for this purpose is ZIF-67, which has a high specific surface area that allows the transport of inhibitors with high capacity. But these containers fail after some time, so to improve the physical properties of the coating systems, g-C3N4 was also used as a mineral material, which of course was also used as a filler.... 

The present work focuses on the sustainable development of an intelligent self-healing anticorrosion coating using nanocontainers based on the aluminium oxide nanostructure-pomegranate peel extract-Ce3+ (Ce-PPE@Cat). The Ce-PPE@Cat nanopigment was introduced into the epoxy film (Ep) to achieve a smart barrier/ self-healing anti-corrosive property. To this end, a couple of characterization tests, including FT-IR, TGA, and, BET have been carried out to investigate the Ce-PPE@Cat nanopigment structure/composition. The effectiveness of the anti-corrosion performance of the established coatings was confirmed by EIS, FE-SEM, and accelerated salt spray test. Furthermore, EIS studies revealed that... 

In this study, MOF / PAN hybrid nanoparticles have been used as active anti-corrosion inhibitors for the first time. At first, UIO-66, PANI, and hybrid nanoparticles were synthesized based on different weight percentages of UIO-66. Their functional groups, crystal structure, nanoparticle morphology, porosity structure, stability and thermal performance were investigated using FT-IR, XRD, FE-SEM, BET, and TGA analyses, respectively. The type of nanoparticle structure formation was investigated by TEM images. The particle size distribution along with their surface charge was determined using DLS analysis. Inhibitory properties of nanoparticles were evaluated by TOEFL polarization method and... 

Quartz crystal microbalance (QCM) is a piezoelectric sensor used to measure the mass of adsorbent deposition at the nanoscale on the surface, real-time and non-destructively. The QCM technique has recently gained extensive attention in the chemical and oil industries and other research fields such as medicine and nanotechnology due to its various applications in the advanced sciences. This technique provides comprehensive insights to scientists in the field of phase equilibrium of low-solubility and solid-liquid interactions. Therefore, many attempts have been made to investigate the interaction phenomenon mechanistically using QCM.Scale formation can have many adverse effects, and... 

One of the chief kinds of receptors in cancer angiogenesis is the tyrosine kinase VEGFR-2. This target receptor is presented in both forms; active and inactive. adenosine triphosphate (ATP) residue is the location of deformational change from inactive to active form. Small molecule inhibitors have been designed for various forms of this receptor. In current study, the interaction of small molecular inhibitors including; Regorafenib, Cabozantinib and Thiosanib with dual VEGFR-2 receptor forms was investigated by molecular dynamics with Gromacs software. Cabozantinib and Regorafenib inhibitors had a lower binding energy in interaction with the inactive state however, Thiosanib inhibitors in... 

In this study, metal-organic frameworks (MOFs) UiO-66 and NH2-UiO-66 were prepared and loaded with 2-mercaptobenzothiazole as corrosion inhibitor .Epoxy coatings containing inhibitor loaded nanoparticles were applied on mild steel to corrosion protection in 3.5 wt.% NaCl solution. Fourier transform infrared spectroscopy (FTIR) was used to confirm Inhibitor loading. In order to estimate the loading amount of corrosion inhibitor, thermogravimetric analysis was investigated. FE-SEM images demonstrated nanoparticle dispersibility in epoxy matrix.The results of electrochemical impedance spectroscopy (EIS) alalysis showed improvement of the corrosion resistance of the coatings containing...