International Journal of Nano Dimension
Year:2013 | Volume:3 | Issue:3 (11)|Papers Count:11

Density functional theory (DFT) calculations were performed to investigate the effects of a carbon nanotube (CNT) on the properties of the fluorouracil (F-Uracil) anticancer drug. To achieve the purpose, a molecular model including both of F-Uracil and CNT molecules was created to represent the CNT@F-Uracil compound. The optimized parameters indicated that the new compound could show new properties different from the original F-Uracil. The obtained chemical shielding parameters also indicated that the electronic properties of oxygen and fluorine atoms could detect notable changes whereas those of carbon and hydrogen atoms are almost negligible. Moreover, the most changes of properties were observed for nitrogen atom number one, in which make the connection link of the CNT group to the F-Uracil molecule. The changes of properties of other nitrogen atom are almost negligible.

An in vitro study was conducted to know the veridical properties of silver nanoparticles synthesized from locally available white button mushrooms (Agaricus bisporus). The characterized colloidal silver nanoparticles exhibited as an excellent virucidal property on viral strain Bacteriophage. The viral inactivation process was increased with increasing the concentration of colloidal silver nanoparticles. The silver nanoparticle at 140-160ppm concentration inhibited the viral growth in host bacterial strain.

The composite powders of barium-magnesium ferrite were prepared using sol-gel auto-combustion and microwave methods. The crystal structure and the shape of nanocomposites have been compared. X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Vibrating Sample Magnetometer (VSM) were used to investigate the structural, morphological and magnetic properties of nanopowder. The formation of pure crystallized nanocomposites occurred when the precursor was heat-treated at 800oC for 2 hours. As a result, the composite powders consist of BaFe12O19 and MgFe2O4 phases. The average crystallite size of the synthesized nanoparticles which were obtained by sol-gel auto-combustion and microwave methods were 32 and 65 nm, respectively.

Nanocrystalline particles of barium hexaferrite has been prepared by the sol-gel auto- combustion method using iron and barium nitrate with a Ba: Fe molar ratio of 1:10. The effect of fuel such as citric acid and aspartic acid was investigated on the structure and magnetic properties of nanoparticles. The results revealed that the formation of barium hexaferrite fine particles is influenced by molar ratio of metal nitrates to fuel. The formation of pure crystallized BaFe12O19 nanoparticles occurred when the precursor was heat-treated at 900oC for 2 h. Nanoparticles of barium hexaferrite with average crystalline size between 60-69 nm has been obtained. X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were employed to identify the structural phases, surface morphology and magnetic properties of the prepared nanoparticles, respectively.  Magnetic measurements showed that the BaFe12O19 nanoparticles exhibited a great coercive field and high saturation magnetization of up to 5100 Oe and 55 emu g-1, respectively.

Recovery Factor is an important parameter in determining commercial viability of the oil Reservoirs. Wettability is a major factor that affects oil Recovery. Therefore, changing rock wettability may enhance oil recovery. In this paper, the effect of polysilicon nanoparticles on wettability change of Iranian carbonate reservoir is investigated. To assess this, hydrophilic changes of carbonate rocks are studied by using the contact angle test. Our results show that with increasing nanoparticle concentration, the contact angle decreases. In the next stage, the effect of adding nanoparticles on water flooding is studied. Our experimental results demonstrated that increasing the nanoparticle concentration up to 0.1 percent increases the recovery but further increase to 0.5 reduces the effect on recovery.

Porous Silicon (PS) layers have been prepared from p-type silicon wafers of (100) orientation. SEM, XRD, FTIR and PL studies were done to characterize the surface morphological and optical properties of PS. The porosity of the PS samples was determined using the parameters obtained from SEM images by geometric method. The refractive index values of the PS samples as a function of porosity were determined by Effective Medium Approximation methods. The influence of current density on porosity and refractive index of PS, were discussed. SEM images indicated that the pores are surrounded by a thick columnar network of silicon walls. This porous silicon layer can be considered as a sponge like structure. The sizes of PS nanocrystallites were determined by XRD studies. FTIR spectra indicated that the porous layer contain SiHn complexes. PL study reveals that there is a prominent emission peak at 606 nm. No spectral shift was observed. These results suggest that this nanocrystalline porous silicon could be a potential candidate for optical as well as optoelectronic device applications.

This paper reports the correlation between film thickness, nanostructure and DC electrical properties of copper thin films deposited by PVD method on glass substrate. X-ray diffraction (XRD) and atomic force microscopy (AFM) were used for crystallography and morphology investigation, respectively. Resistivity was measured by four point probe instrument, while a Hall effects measurement system was employed for Hall Effect analysis. The grain size calculated from XRD and AFM, roughness, resistivity, hall coefficient, carrier concentration and mobility were plotted as a function of thickness. The result showed amorphous structure for 20 nm thickness, but with increasing the film thickness, Cu (111) preferred orientation was observed. The grain size, roughness and concentration of carriers increased and resistivity, hall coefficient and mobility decreased with increasing the film thickness.  The result of copper thin films electrical investigation showed the value of resistivity and concentrations of carriers come to bulk state value at approximately 160 nm thickness.

A new mixed  halo chromate  nanoparticle compound was synthesised and characterized. Triphenylphosphonium trifluoroiodochromate (III) [P (C6H5) 3H]+[CrF3I]- nanoparticle was synthesized by using triphenylphosphonium  iodide reaction with CrF3, in the presence of  3-mercaptopropionic acid. This method is a simple and direct method. The product was characterized by spectroscopic and analytical methods such as 31P-NMR, FT-IR, XRD, SEM. Theoretical calculations were used for the structural optimization of this compound. The structure of compound has been calculated and optimized by the density functional theory (DFT) based method at B3LYP/6-311G levels of theory, using the Gaussian 98 package of programs. The comparison between theory and experiment is made. On the base of application of scanning electron microscopy (SEM) is showed about 54 nm particle sizes.

ZrO2 nanopowder was prepared by the sol-gel auto-combustion method. The product was characterized by X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX) and scanning electron microscopy (SEM). The average crystalline size of ZrO2 was obtained 62 nm. Also, photocatalytic removal of nitrophenol from aqueous solution by using nanoscale ZrO2 under UV light irradiation was studied. The effect of initial pollution concentrations in 3, 5 and 10 ppm in presence of ZrO2 nanoparticles was studied in photocatalytic degradation process. Nitrophenol was degraded 84, 78 and 66% in the presence of 0.04 g of ZrO2 within 70 minutes.

For the first time this study reported the success of using nanocrystalline hexagonal close-packed (hcp) nickel (Ni) modified composite graphite (CG) electrode (hcp-nano Ni/CG) for the electrocatalytic oxidation of glycerol in alkaline medium (0.1 M KOH). The hcp-nano Ni/CG electrode had an improve response and specificity on the electrocatalytic oxidation of glycerol over the bare CG. The electrocatalysis was the result of the formation of NiOOH during the oxidation process. The process was influenced by scan rate and concentration of glycerol. A linear relationship of concentration with current was obtained over concentration range of 0.5-12.0 mM glycerol with limit of detection (S/N=3) at 0.033 mM glycerol. The hcp nano Ni modified CG electrode was applied for direct determination of free glycerol in biodiesel samples. As a glycerol sensor the hcp nano Ni modified CG is quite stable.

Most reservoir fluids contain heavy paraffinic compounds that may precipitate as a solid or solid like material called wax if the fluid is cooled down. Wax precipitation is a phenomenon of considerable importance in oil industry. An increase in aggregation results in enhanced oil viscosity. This however causes significant negative effects on production, transportation and processing of crude oil. So, structural characterization of wax is considered to be important topic. In this work, normal paraffin molecules C20, C21, C23, C24, C25, C27, and C29 have been considered as representatives of wax molecule. Intermolecular forces have been calculated using quantum mechanics and statistical analysis. Second virial coefficients have been obtained for these molecules by applying intermolecular potential energy. Finally SRK and PR equation of states parameters have been achieved to have molecular consideration of wax structure.