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Research subject: In this research we studied the anti-corrosion properties of epoxy coating containing anti-corrosion pigment zinc phosphate with hydrophobic nano silica with different percentage also for determine the optimal conditions for preparation of nanocomposite Taguchi experimental design method was used.
 
Research approach: Anti-corrosion properties of epoxy coating under the influence of very important factors such as the percentage of nano silica, anticorrosive pigment and pigment to resin ratio according to model L9 taguchi method was studied and analyzed. Anti-corrosion properties of epoxy coatings were studied by electrochemical impedance spectroscopy test (EIS) in 3/5% NaCl aqueous solution and salt fog test (salt spray). To investigate the distribution of nano silica particles in epoxy resin were analyzed by transmion electron microscope (TEM) and scanning electron microscope (SEM). The results show that using from zinc phosphate and nano-silica was able to improve the corrosion resistances.
 
Main results:Results shows that addition of zinc phosphate and nano silica to epoxy resin caused a decrease in number of blisters and corrosion products after exposure to corrosion test based on the results in Nyquist and Bode plots, also the similarity in results was observed for the epoxy coating loaded according to the optimum conditions with 8% zinc phosphate, 3% nano silica and pigment to resin ratio of one according to salt spary. The significance levels of the experimental parameters, which indicate how the factors affect the compressive addition of zinc phosphate and nano silica to epoxy resin, were determined by using variance (Anova) method.

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In, this research, the effects of adding silica and multiwall carbon nanotubes (MWCNT) nano particles on the low velocity impact response are experimentally studied. Vacuum assisted resin transfer molding (VARTM) method has been used to manufacture nano composite with 11 layers of plain weave carbon fibers 200 g⁄m^2 , resin R510 and hardener H515 with 66% fiber volume fraction. Samples made of nano silica and MWCNT particles have been dispersed with 1 wt. %. The prepared CARALL is made of two Aluminum 2024 facing sheets. Low velocity impact tests have been conducted using by drop weight device at the impact energy of 20, 40 and 60 j with velocity of 2.6, 3.68 and 4.5 m⁄s . The results of the low velocity impact experiments indicates that the MWCNT improves performance of fiber metal composite material and the effects of MWCNT in improving the impact properties of fiber metal laminate composite is better than of nano silica. Better adhering and dispersion of MWCNT and strong interfacial creation are some other effect factors of impact response sample reinforced with multiwall carbon nanotubes in comparison to nano silica.

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Elastomers are a group of polymeric materials that have unique properties, including time-dependent behavior and time-independent, the mechanical behavior of this material is affected by various factors. In this study, the effect of increasing the silica nanoparticles and strain rates in two quasi-static and dynamic states on the tensile behavior of HDPE / POE has been investigated. For this purpose, an elastomeric material was first created with 40% HDPE and 60% POE mixing ratio. Then with increasing Nano silica particles, 4 sample types including 3 samples 0.7%, 1% and 1.4%, and one sample of HDPE/POE was fabricated. The samples were loaded at strain rate of 0.04 1⁄s, 0.07 1⁄s , 0.1 1⁄s , 0.14 1⁄s , 0.17 1⁄s in a quasi-static tensile state. In dynamic mode, tensile load with a strain rate of 160 1⁄s and 100 1⁄s was applied to the specimens using a new fixture designed on the low velocity impact test machine (Drop weight impact test machine). In the dynamic loading, the behavior of the elastomeric material is extremely dependent on the strain rate, with increasing the strain rate the level of stress and forces in both quasi-static and dynamic loads will be increase. The increase in force levels in dynamic loading is much more than static. Also, the new designed mechanism provides access to dynamic tensile data at different strain rates in a low velocity impact machine. On the other hand, with increasing Nano silica percentage, the tensile strength of the samples is noticeably increased.

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In recent years, the use of nano-materials in different engineering and science projects has increased. The study of the impact of nano-materials in combination with other civil engineering constituents in different geotechnical and geo-environmental engineering projects is very common. This study is aimed to investigate the mechanism of cadmium retention in the process of cement based solidification/stabilization of cadmium contaminated bentonite in the presence of nano-silica. The mechanism of contaminant retention is investigated with the evaluation of cadmium and nano-silica behaviour with change in pH of the environment, adsorption, TCLP results, and evaluation of XRD experimental achievements. The bentonite sample for this research is taken from Iran-Barit Company. To establish the availability of silica ions for interaction with cement and bentonite at different pH, a series of solubility experiments of nano-silica at different pH levels were performed. The results of solubility experiments show that as the pH increases to the alkaline range, the solubility of nano-silica noticeably increases. This fact proves that at the high range of pH due to the use of cement, the required pH conditions for solubility of nano-silica will be provided. Therefore, there will be more possibility for the formation of CSH component. Cadmium nitrate was used to contaminate the bentonite sample for the experimental part. For this purpose, bentonite samples were mixed with 10, 30, and 50 cmol/kg-soil of cadmium nitrate in the electrolyte soil ratio of 20:1. Then, these samples were shaken for two hours in every 24 hours. This process was repeated for 96 hours. After this equilibrium step, the soil suspension was centrifuged. After drying these laboratory contaminated samples, they were solidified/stabilized with different percentages of cement and nano-silica. The results of this paper indicate that the contaminant adsorption and retention of cadmium by bentonite is less than that of adsorption for zinc and lead. The achieved results of TCLP experiments for solidified/stabilized samples with different percentages of cement indicate that the EPA criteria for TCLP experiment which emphasizes for test performance after 28 days, is not suitable for solidification and stabilization of cadmium. In fact, a longer period is necessary to achieve equilibrium and stable results. Furthermore, the results show that due to the low adsorption of cadmium by bentonite and due to the noticeable reduction of pH at the presence of cadmium ions, the required percentages of cement for solidification/stabilization of cadmium contaminated bentonite is much more than the required quantity of cement for other heavy metal contaminated bentonite samples. In addition, the results of XRD experiments show that the pozzolanic interaction process is more efficient in the presence of nano-silica. Furthermore, based on the results of TCLP experiments, the formation of CSH in the presence of nano-silica contributes to the contaminant retention by solidification/stabilization of cement based cadmium contaminated bentonite. Finally, according to the results of this study, in solidified/stabilized samples by mixtures of cement and nano-silica, it is shown that due to the contribution of silica ions in pozzolanic interactions, the solidification is the governing phenomenon for the prevention of heavy metal leachate from solidified/stabilized samples.