Sharif Digital Repository

Poly(vinylidene fluoride)/poly(vinyl acetate)/carbon nanotubes, PVDF/PVAc/CNT, composite films were prepared at various compositions via a solution casting method. The amorphous PVAc formed a miscible blend with PVDF and drastically improved dispersion of CNT in PVDF/CNT composites. Combination of ductile PVAc and rigid CNT had favorable effects on mechanical properties of PVDF. The elongation of PVDF increased from 8% to 300% with addition of 40 wt% PVAc and 0.5 wt% CNT and the modulus at 1.5 wt% CNT was almost 2.3 fold of that of the neat PVDF while retaining high ductility and tensile strength. XRD and FTIR results showed that CNT favored formation of β-crys-talline phase in PVDF. Also... 

In this work, flexible thermoelectric fabrics, polyester/yarn fabrics coated with polyaniline/carbon nanotube (PANI/CNT) nanocomposite, were fabricated by sequential processing: (I) polyaniline/carbon nanotube nanocomposites preparation by a one-step in-situ polymerization and (II) dip coating of a mixture solution of CNT-doped PANI on a polyester/yarn fabric. Nanocomposites were synthesized with various CNT content (0.5, 2.5, 5, and 10 wt%) and characterized using different methods. The Seebeck coefficient and electrical conductivity measurements were used to determine their thermoelectric properties. The results revealed significant improvement in both electrical conductivity and the... 

In this work, flexible thermoelectric fabrics, polyester/yarn fabrics coated with polyaniline/carbon nanotube (PANI/CNT) nanocomposite, were fabricated by sequential processing: (I) polyaniline/carbon nanotube nanocomposites preparation by a one-step in-situ polymerization and (II) dip coating of a mixture solution of CNT-doped PANI on a polyester/yarn fabric. Nanocomposites were synthesized with various CNT content (0.5, 2.5, 5, and 10 wt%) and characterized using different methods. The Seebeck coefficient and electrical conductivity measurements were used to determine their thermoelectric properties. The results revealed significant improvement in both electrical conductivity and the... 

In this study, polypropylene/carbon nanotube nanocomposites were prepared via in situ polymerization using a bi-supported Ziegler-Natta catalytic system. In this system, magnesium ethoxide and multiwall carbon nanotubes (MWCNTs) are jointly used as catalyst supports. SEM images reveal the distribution and quite good dispersion of MWCNTs throughout the polypropylene (PP) matrix. The thermal properties of the samples were examined using DSC and TGA tests. The results show that the crystallization temperature of the nanocomposites significantly increases while the melting point is not markedly affected. In addition, the thermal stability is improved. The melt rheological properties of PP/MWCNT... 

This investigation focused on a comparison between hydroxyapatite (HA) and carbon-nanotube-reinforced hydroxyapatite composite (CNTs/HA) coatings. The HA and CNTs/HA composite (with 5wt% CNTs) coatings were prepared with the sol-gel method on 316L stainless steel. Phase evaluation by means of XRD and Raman spectroscopy was performed on the HA and CNTs/HA composite coatings. The coatings were immersed in simulated body fluid (SBF) in order to evaluate the biological properties of the coatings. During the first week of immersion, the increase in the amount of Ca2+ precipitation in the SBF when CNTs/HA was used was lower than for the HA coatings. This behavior can be related to the difference... 

In this work, the synthesis and characterization of a new nanocomposite from carbon nanotubes-graft-polymer (CNTs-g-P) is reported. The products were obtained by the filling of multi-walled carbon nanotubes (MWCNTs) (inner diameter 2040 nm) with CoFe2O4 magnetic nanoparticles, been grafted with poly (caprolactone). The filling process was carried out by using acid treatment through wet chemistry. The structure and the properties of the new nanocomposite were studied with TEM, VSM, TGA, and spectroscopic techniques. © 2009 World Scientific Publishing Company  

In this paper, CuO/CNT nanocomposite was synthesized and its photocatalytic dye degradation ability for colored textile wastewater was studied. The characteristics of the nanocomposite were investigated by XRD, SEM and FTIR. The photodegradation of Direct Red 31 (DR31) and Reactive Red 120 (RR120) by CuO/CNT in presence of H2O2 was investigated. Photocatalytic dye degradation was determined by UV-vis spectrophotometer. Effects of catalyst dosage, initial dye concentration and salt on photodegradation performance were studied. The photocatalytic dye degradation ability of pure CuO and CuO/CNT nanocomposite is 78 % and 89 % for DR31 and 70 % and 87 % for RR120, respectively. The results showed... 

In this study, ultra-fine grained Cu and Cu + carbon nanotube (CNT) nanocomposites were prepared through a processes combining flake powder metallurgy, hot pressing, and high-pressure torsion (HPT). The effects of grain refinement and CNT reinforcement on the microstructure, hardness, wear resistance, and corrosion behavior of the newly developed nanocomposites were investigated. The results indicated that the HPT process decreased the grain size of Cu and Cu + CNT by 67.7% and 68.1%, respectively, and increased their microhardness by 151% and 132%. The addition of CNTs substantially improved the tribological behavior of Cu by generating a mechanically mixed carbon- and oxide-rich layer.... 

In this study, ultra-fine grained Cu and Cu + carbon nanotube (CNT) nanocomposites were prepared through a processes combining flake powder metallurgy, hot pressing, and high-pressure torsion (HPT). The effects of grain refinement and CNT reinforcement on the microstructure, hardness, wear resistance, and corrosion behavior of the newly developed nanocomposites were investigated. The results indicated that the HPT process decreased the grain size of Cu and Cu + CNT by 67.7% and 68.1%, respectively, and increased their microhardness by 151% and 132%. The addition of CNTs substantially improved the tribological behavior of Cu by generating a mechanically mixed carbon- and oxide-rich layer.... 

In this study, ultra-fine grained Cu and Cu + carbon nanotube (CNT) nanocomposites were prepared through a processes combining flake powder metallurgy, hot pressing, and high-pressure torsion (HPT). The effects of grain refinement and CNT reinforcement on the microstructure, hardness, wear resistance, and corrosion behavior of the newly developed nanocomposites were investigated. The results indicated that the HPT process decreased the grain size of Cu and Cu + CNT by 67.7% and 68.1%, respectively, and increased their microhardness by 151% and 132%. The addition of CNTs substantially improved the tribological behavior of Cu by generating a mechanically mixed carbon- and oxide-rich layer.... 

The electrochemical oxidation of sumatriptan on the surface of carbon paste electrode modified with multi-walled carbon nanotube and cobalt methyl-salophen complex is studied by using cyclic voltammetry and polarization studies. The results indicate that the drug is irreversibly oxidized in a one electron oxidation mechanism. It was found that the peak potential shifted negatively with increasing pH, confirms that H + participate in the oxidation process. The electrode is shown to be very effective for the detection of sumatriptan in the presence of other biological reductant compounds. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of... 

Reinforced polydiphenylamine (PDPA) nanocomposite was synthesized by oxidation of diphenylamine in 4molL-1 sulfuric acid solution containing a fixed amount of carbon nanotubes (CNTs) in the presence of cetyltrimethylammonium bromide (CTAB). The surface characteristic of PDPA and PDPA/CNT nanocomposites was investigated using scanning electron microscopy (SEM). The prepared PDPA/CNT nanocomposite was used as an extraction medium for microextraction in packed syringe (MEPS) of selected pesticides from aquatic environment. The effect of CNT doping level and the presence of surfactant on the extraction capability of nanocomposite was investigated and it was revealed that when 4% (w/w) of CNT in...