Journal of Applied Research in Chemistry
Year:2012 | Volume:6 | Issue:3|Papers Count:9

In this paper, Al2O3-MWCNT hybrid was prepared by a very simple and economical wet chemical method. The as-prepared hybrid was used for emulsion preparation with other ingredients such as water, suitable surfactant, kerosene and 2-propanol. It is observed that cationic surfactants (CTAB) is superior to the anionic (SDBS) and non-ionic (TX-100) surfactants and has suitable stability in different temperatures. According to the interfacial tension and contact angle experiment results, the as-prepared nanofluid can be used in chemical enhanced oil recovery (C-EOR) especially for the carbonate reservoirs. Morphology and structure of the as-prepared hybrid were recognized by XRD and FE-SEM.

In this research, a novel chemical solution was introduced as a cleaner reagent for removing metallic lead pollution, as a fouling metal, from chromium surfaces. The cleaner solution contains hydrogen peroxide (H2O2) as oxidizing and EDTA as a chelating agent of lead ions. The effect of some experimental parameters such as oxidizing and chelating agent concentration, temperature and stirring speed of the mixture (rpm) during the operation on the efficiency of lead cleaning procedure was investigated by means of sequential experimental method. The results of scanning electron microscopy (SEM/EDAX) showed that by using this procedure, the lead pollution layer could be completely removed from the real chromium surfaces without corrosion of the original surface. However, our results show that under optimum conditions for the complete and fast removing of lead pollution layer from chromium surfaces, that is, H2O2 6% (V/V), EDTA 30 mM, stirring speed of the mixture 50 rpm and temperature 30oC, to achieve the most cleaned sample, the total removal time of 3 g fouling lead layer is only 12 minutes. Finally, the results of this study illustrated that the efficiency of the proposed EDTA/H2O2 cleaning method is higher compared to the previous cleaning experimental techniques.

In this research, extraction of the oils from 15 varieties of Iranian date seed was investigated in laboratory scale and pilot plant. The yields of oil extraction in laboratory scale were obtained to be 6.2% to 13.2% with average 9.55%. Obtained optimized conditions were obtained using petroleum ether solvent in laboratory scale. The yield of oil extraction in pilot plant scale was obtained to be 6.6%.

In the past few years sulfur removal from fuels has attracted much attention due to the strict environmental regulations. Nanoparticles are widely used as sorbent because of their unique properties. Application of the external magnetic fields has provided a promising solution in separation science. In this study through immobilization of ionic liquids onto the surface of iron oxide magnetic nanopartiocles, a new Nano sorbent for extractive removal of the gasoline sulfur compounds was prepared. Magnetic characteristic of the nanosorbents provide the ease of separation, and interaction of the ionic liquid with sulfur compounds makes the separation possible. Reusability of these nanosorbents for a couple of cycles was possible. Effective factors of nanosorbent performance have been optimizedand successfully used for the desulfurization of a model gasoline and a real one.

Nowadays 2-mercaptobenzothiazole is widely used in vulcanization process for preparation of rubber products. An important disadvantage of this accelerator is its poor dispersion in polymer matrix. In this study in order to increase the lipophilic property of the accelerator and to improve the dispersion of it in polymer matrix and increase its efficiency, some of the new derivatives of benzothiazole family were prepared by adding lipophilic chains obtained from the reaction of 2-mercaptobenzothiazole with alkylhalyds, such as benzoyl chloride and 4-nitro benzyl bromide. Rheological and physico-mechanical properties of rubber compounds prepared by new accelerators were investigated. Results showed that s-benzothiazole-2-yl tiobenzoat increases the scorch time of the compound, while the other properties were preserved. This is very important for the rubber products that need more time for processing before the vulcanization would start. The second compound that was prepared by 2-(4-nitrobenzil) tiobenzothiazole did not good results due to passive participation in vulcanization process.

Influence of nanosilica on surface properties of poly(butylene terephthalate) was investigated by making use of Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurement (CAM), scanning electron microscopy (SEM) and reflectance spectroscopy (RS). FTIR results indicated that surface groups of silica have some interfacial interactions and bonding with carboxyl or hydroxyl end groups of PBT chains. AFM and SEM figures of the resultant Nano composites illustrated increased surface roughness compared to pure PBT. Optical properties of nanocomposite films were finally determined by the aid of reflectance spectrophotometer.

Sevochloran, (CF3)2CHOCH2Cl, was synthesized in 87% yield from (CF3)2CHOH, HFIP, alcohol and trioxane using AlCl3 as catalyst and chlorinating agent. The resulting chloromethyl ether was then used as alkylating agent to perform nucleophilic substitution reaction with different N and O nucleophiles. The nucleophilic substitution reactions withphenol, 2,4-dimethyl phenol and 2,5-di-tBu hydroquinone were carried out and the resulting O-alkylated products were obtained in 96, 94 and 20% yields, respectively. The N-alkylation reactions with 4-methyl imidazole, triethylenediamine, dimethylaminopyridine and 1-benzyl imidazole were also successful and the corresponding products were obtained in 40, 55, 85 and 71%, respectively. 19F NMR spectroscopy was used as a powerful method to distinguish if new O-C and N-C bondshave been formed by searching the presence of (CF3)2CH in the resulting products. In the case of 4-methyl imidazole, two products were characterized in the reaction mixture and it was realized that both N cites are potentially active for the nucleophilic substitution reaction. In addition, from the analysis of the reaction mixture of dimethylaminopyridine, it was found out that pyridine nitrogen reacts with sevofluorane under the reaction condition experienced.

The effect of salt concentration on thermodynamic stability of aggregations in anionic and cationic-rich mixtures of CTAB (cetyltrimethylammonium bromide) and SDS (sodium dodecyl sulfate) were investigated using conductometryand surface tension. The micellization free energy (DGmic) by critical micellization concentration (CMC) and degree of counter ion binding were determined. The results showed that the formation of mixed aggregates was more spontaneous in anionic-rich than cationic rich region. Also, electrostatic repulsion between head groups was reduced by using salt addition and micelle was formed. It was observed that, for both the planar air/aqueous interface and micellar systems, the nonideality decreased as the amount of electrolyte in the aqueous medium was increased. This was attributed to a decrease of the surface charge density caused by increasing the concentration of bromide ions. Also, the thermodynamic stability of micelles in presence of salt for removing oily dirt was investigated.