Several schottky diodes were fabricated from polyaniline/ Carbon nanotube (single and multiwalled) composites. These composites were synthesized with different concentration and two carbon nanotubes types, Single and Multi-Walled Carbon Nanotubes (SWCNT & MWCNT). Aluminum and silver paste were chosen as schottky and ohmic contact respectively. physical and electrical were used to studied these composite by using Atomic Force Microscopy (AFM) and electrical measurements. The Root Mean Square RMS surface roughness of the composite samples was found to be around 4nm. The currentvoltage characteristic were measurements for all samples in the bias range ±15V at room temperature. The results shows the increasing in carbon nanotubes concentrations increase the current intensity, and the single walled gave higher current intensity than multi walled carbon nanotubes . The current –voltage characteristics for the composite devices shows the current at lower voltages obeys ohm’s contact while at higher voltages child’s law is dominated.
In this study, nanocomposites have been prepared by adding
multiwall carbon nanotubes (MWCNTs) with weight ratios (0, 2, 3,
4, 5) wt% to epoxy resin. The samples were prepared by hand lay-up
method. Influence of an applied load before and after immersion in
sodium hydroxide (NaOH) of normality (0.3N) for (15 days) at
laboratory temperature on wear rate of Ep/MWCNTs
nanocomposites was studied. The results showed that wear rate
increases with increasing the applied load for the as prepared and
immersed samples and after immersion. It was also found that epoxy
resin reinforced with MWCNTs has wear rate less than neat epoxy.
The sample (Ep + 5wt% of MWCNTs) has lower wear rate. The
immersion effect in base so
Ferrite with general formula Ni1-x Cox Fe2O4(where x=0.0.1,0.3,0.5,0.7, and 0.9), were prepared by standard ceramic technique. The main cubic spinel structure phase for all samples was confirmed by x-ray diffraction patterns. The lattice parameter results were (8.256-8.299 °A). Generally, x -ray density increased with the addition of Cobalt and showed value between (5.452-5.538gm/cm3). Atomic Force Microscopy (AFM) showed that the average grain size and surface roughness was decreasing with the increasing cobalt concentration. Scanning Electron Microscopy images show that grains had an irregular distribution and irregular shape. The A.C conductivity was found to increase with the frequency and the addition of Cobal
... Show MorePolyaniline (PANI) polymer was successfully prepared by the chemical oxidation method at 0 oC. Polyaniline-nano grapheme (GN) powder nanocomposites were prepared by the addition of GN with different weight ratios (0.1, 1, 5, and 10 g wt. %) during the polymerization of PANI. It was found that the polymerization reaction of poly-aniline was exothermic. The effect of adding nano-graphene powder during polymerization process on the time and temperature of the reaction was studied. The resulting polymer was diagnosed using several methods, including Fourier transform infrared spectroscopy (FT-IR) and UV-VIS spectrophotometry. The results of FTIR demonstrated a shift to higher wave numbers in the peaks of nanocomposites, due
... Show MoreIn this paper, A.C conductivity of micro and nano grain size- TiO2 filled epoxy composites is measured. The dielectric material used is epoxy resin, while micro and nano-sized titanium dioxide (TiO2) of grain size (1.5μm, and 50nm) was used as filler at low filler concentrations by weight (3%, and 5%). Additionally the effect of annealing temperature range (293-373)º K and at a frequency range of 102-106 Hz on the A.C conductivity of the various specimens was studied.
The result of real permittivity for micro and nanocomposite show that the real permittivity increases with decreasing frequency at range of 102-106Hz. The micron-filled material has a higher real relative permittivity than the nano-filled this is true at all the temper
The electrical properties of the AlNiCo thin films with thickness (1000oA) deposited on glass substrates using Ion – Beam sputtering (IBS) technique under vacuum <10-6 torr have been studied . Also it studied the effect of annealing temperature from this films , It is found that the effective energy decrease with increase of temperature and the conductivity decrease with increase temperature 323oK but after this degree the conductivity increasing .
In this work, polyvinylpyrrolidone (PVP), Multi-walled carbon nanotubes (MWCNTs) nanocomposite was prepared and hybrid with Graphene (Gr) by casting method. The morphological and optical properties were investigated. Fourier Transformer-Infrared (FT-IR) indicates the presence of primary distinctive peaks belonging to vibration groups that describe the prepared samples. Scanning Electron Microscopy (SEM) images showed a uniform dispersion of graphene within the PVP-MWCNT nanocomposite. The results of the optical study show decrease in the energy gap with increasing MWCNT and graphene concentration. The absorption coefficient spectra indicate the presence of two absorption peaks at 282 and 287 nm attributed to the π-π* electronic tr
... Show MoreFunctionalized-multi wall carbon nanotubes (F-MWCNTs) and functionalized-single wall carbon nanotubes (F-SWCNTs) were well enhanced using CoO Nanoparticles. The sensor device consisted of a film of sensitive material (F-MWCNTs/CoONPs) and (F-SWCNTs/CoO NPs) deposited by drop- casting on an n-type porous silicon substrate. The two sensors perform high sensitivity to NO2 gas at room temperatures. The analysis indicated that the (F-MWCNTs/CoONPs) have a better performance than (F-SWCNTs/CoONPs). The F-SWCNTs/CoONPs gas sensor shows high sensitivity (19.1 %) at RT with response time 17 sec, while F-MWCNTs/CoONPs gas sensor show better sensitivity (39 %) at RT with response time 13 sec. The device shows a very reproducible sensor p
... Show MoreSome of structural ,and electrical properties of pure and zinc (Zn) doped cadmium telluride thin films with impurity percentages (0.5, 1, 1.5)%, deposited on hot glass substrate (temperature equals to 423K) of thickness of 300nm and rate deposition of 0.5 nm.s-1 by thermal co-evaporation technique under vacuum of (2×10-5)Torr have been investigates. The structural properties for the prepared films were studied before and after. doping process by analysis of the X-ray diffraction, and it appeared that pure and dopant CdTe thin films are polycrystalline and have the cubic structure with preferential orientation in the [111] direction, and the crystal structure of the films were improved due to doping process. From d.c
... Show MoreMWCNTs-OH was used to prepare a flexible gas sensor by deposition as a network on a filter cake using the method of filtration from suspension (FFS). The morphological and structural properties of the MWCNTs network were characterized before and after exposure to Freon gas using FTIR spectra and X-ray diffractometer, which confirmed that the characteristics of the sensor did not change after exposure to the gas. The sensor was exposed to a pure Freon134a gas as well as to a mixture of Freon gas and air with different ratios at room temperature. The experiments showed that the sensor works at room temperature and the sensitivity values increased with increasing operating temperature, to be 58% unt
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